SSL3252UK/C2,515_技术文档

SSL3252

Photo flash LED driver

Rev. 1 — 7 July 2011

Product data sheet

1. General description

The SSL3252 is a photo flash LED driver designed for battery operated mobile devices

such as mobile phones and PDAs. The boost converter delivers high performance and

drives a single or dual high brightness LED at up to 500 mA with over 85 % efficiency. The

driver can be programmed to operate in Flash mode, Torch mode, Assist light mode, or

Indicator mode.

The small silicon size and the high internal switching frequency of 2 MHz minimize the

size of the application and make the SSL3252 very suitable for mobile phones where

space is limited, and only requiring three external components. System protection has

been a very important part of the SSL3252 design, so a time-out function can be

programmed to prevent overstressing the LED, and the driver itself is protected from

overheating.

2. Features and benefits

 High power single or dual LED output driving up to 500 mA flash current

 Separate indicator LED output of 2.5 mA to 10 mA

 High side current source for main and indicator LEDs

 Output voltage of up to 8.85 V

 Wide input voltage ranging from 2.5 V to 5.5 V

 High efficiency of over 85 % at optimum output current

 Switching frequency of 2 MHz

 Flash mode, Assist light mode, Torch mode and Indicator mode are supported

 Internally timed flash operation up to 850 ms

 I²C-bus, programmable up to 400 kHz

 Strobe signal to avoid I²C latency for the flash

 Direct enable signals for stand-alone operation

 Forward voltage sensing to allow single/dual LED detection

 Soft start/soft stop

 Integrated protection circuits for enhanced system reliability:

 Internal time-out

 OverTemperature Protection (OTP)

 UnderVoltage LockOut (UVLO)

 OverVoltage Protection (OVP)

 Short-circuit protection

 Inductor peak current limit and broken coil detection

 Low device shut-down current of less than 1 A

 Small WLCSP12 package with 500 m bump pitch

SSL3252

NXP Semiconductors

Photo flash LED driver

3. Applications

 Photo flash LED driver for mobile phones and digital cameras

 White LED driver for battery powered portable devices

4. Ordering information

Table 1.

Ordering information

Type number

Package

Name

Description

Version

SSL3252UK/C2

WLCSP12

wafer level chip-size package; 12 bumps; 1.58  2.06  0.6 mm

SSL3252UK

5. Block diagram

V

BAT

4.7 µF

2.2 µH

PGND

VIN

LX

VO

4.7 µF

LINEAR

CURRENT

SOURCE

IF_SEL

PGND

CURRENT

FEEDBACK

SYNCHRONOUS

SWITCHER

SDA/EN2

SCL/EN1

I

source

2

I C-BUS

INTERFACE

AND CONTROL

UP CONVERTER

LED one or two LEDs

STRB/2LED

TORCH

400 kHz

R1 R2

(1)

R3

(2)

R4

(2)

I_IND

GND

PGND

014aaa297

(1) Pull-down resistor R2 is connected to STRB/2LED pin only in I²C mode.

(2) Pull-down resistors R3 and R4 are connected to the EN1 and EN2 functions of the SCL/EN1 and SDA/EN2 pins only in Direct

enable mode.

Fig 1. Block diagram

SSL3252

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 1 — 7 July 2011

2 of 30

SSL3252

NXP Semiconductors

Photo flash LED driver

6. Pinning information

6.1 Pinning

SSL3252UK/C2

Bump A1

Index area

1

2

3

A

B

C

D

Transparent top view

002aag318

Fig 2. Pin configuration

6.2 Pin description

Table 2.

Symbol

PGND

GND

Pin description

A1

A2

A3

B1

B2

B3

C1

Type

Description

ground

power ground

ground

signal ground

VIN

input

input voltage

LX

analog input

input

inductor connection

Torch mode activate

indicator LED current source

output voltage

TORCH

I_IND

VO

analog output

STRB/2LED C2

input/output (I/O) strobe signal input to trigger flash in I²C mode;

2LED signal output in Direct enable mode (open-drain)

IF_SEL

C3

input

interface select; choose between Direct enable mode

or I²C mode

LED

D1

D2

analog output

main LED current source

SDA/EN2

input/output (I/O) serial data line in I²C mode / enable 2 in Direct enable

mode

SCL/EN1

D3

input

serial clock line in I²C mode / enable 1 in Direct enable

mode.

SSL3252

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 1 — 7 July 2011

3 of 30

SSL3252

NXP Semiconductors

Photo flash LED driver

7. Functional description

7.1 Introduction

The SSL3252 is a boost converter intended to drive either a single high power flash LED

or two high power flash LEDs in series. The LED current is controlled by the output

voltage of the boost converter and the integrated linear current source. The SSL3252 has

two interface modes and six operational modes. The interface mode is selected by the

interface select pin IF_SEL. Depending on the Interface mode selected, the device can

either be controlled by an I²C-bus interface, or external enable lines.

The interface modes are:

• I²C mode

• Direct enable mode

The operational modes are:

• Standby mode

• Shut-down mode

• Flash mode

• Torch mode

• Assist light mode

• Indicator mode

In all LED modes, to ensure a constant switching frequency, the regulated converter

employs Pulse Width Modulation (PWM).

In applications where the required LED voltage is lower than the applied input voltage, the

converter switches to linear mode. The excess voltage difference between the required

LED voltage and input voltage is now compensated by increasing the voltage over the

linear current source and therefore on the LED pin.

Apart from the main LED(s), a separate indicator LED can be driven from the SSL3252.

This is driven by a linear current source circuit that operates independent of the switch

mode converter for the main LED(s).

7.2 Interface modes

The device is equipped with two interfaces: I²C and Direct enable. Which interface mode

is used is defined by the level of the IF_SEL pin. Table 3 describes the interface

possibilities.

Table 3.

Interface modes

Interface mode

I²C mode

IF_SEL

Relevant controls

1

0

SDA, SCL, STRB/2LED, TORCH

EN1, EN2, TORCH

Direct enable mode

SSL3252

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 1 — 7 July 2011

4 of 30

SSL3252

NXP Semiconductors

Photo flash LED driver

7.2.1 Using the direct enable control

When the Direct enable mode is used, the device can be switched to the various

operational modes using the TORCH, EN1 and EN2 control signals. The definitions of

these control signals are given in Table 4. The EN1 and EN2 functions of the SCL/EN1

and SDA/EN2 pins have a higher priority than the pin TORCH. Figure 3 shows all the

possible transitions between the various interface modes.

The device is in Shut-down mode when all control pins (IF_SEL, EN1, EN2, TORCH) are

LOW.

Shut-down

mode

Indicator

mode

Torch

mode

Flash

mode

Assist light

mode

014aaa303

Fig 3. Direct enable mode transitions

Table 4.

Direct enable logic definition

IF_SEL SCL/ SDA/ TORCH Mode

Output states

EN1 EN2 pin

0

Shut-down Outputs disabled; shut-down current less than

1 A

0

1

0

1

0

1

Torch

Fixed value; 40 mA dual LEDs; 80 mA single LED

X^[1]

Assist light Fixed value; 40 mA dual LEDs; 80 mA single LED

Indicator

Flash

Fixed value 2.5 mA

Fixed value; 320 mA dual LEDs;

500 mA single LED

[1] X = Don’t care.

SSL3252

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 1 — 7 July 2011

5 of 30

SSL3252

NXP Semiconductors

Photo flash LED driver

7.2.2 Using the I²C control

Using the I²C interface mode enables additional features and settings as described in the

I²C register set Table 6. The definition of the control pins is given in Table 5. Figure 4

shows the typical transitions between the various modes.

The device cannot enter Shut-down mode when in I²C mode. The lowest power

consumption can be achieved in Standby mode. When using I²C, the device can still be

put in Shut-down mode by first making all control pins LOW (SDA = SCL = TORCH = 0)

and then going to Direct enable Shut-down mode by making IF_SEL LOW.

Flash

without

strobe

Flash with

Shut-down

edge sensitive

mode

strobe

Flash with

level sensitive

strobe

Standby

mode

Output

ON

Torch

mode

Indicator

mode

Assist light

mode

014aaa304

Fig 4. I²C mode typical transitions

I²C logic definition

Table 5.

IF_SEL Torch mode; Output ON; Output

Output

mode;

TORCH Mode

Output states

bit D4;

bit D3;

mode;

Reg 04h

bit D1;

Reg 04h

bit D0;

Reg 04h

1

X

1

0

X

0

1

Standby

Torch

Outputs disabled; standby current

less than 10 A

X

0

Depends on the register value;

between 20 mA and 160 mA;

TORCH signal triggers this mode

only if the registers allow it

1

X

1

0

1

0

1

X

Assist light Depends on the register value;

between 20 mA and 160 mA

Indicator

Depends on the register value;

between 2.5 mA and 10 mA

Flash

Depends on the register value;

between 200 mA and 500 mA for a

single LED and 200 mA to 400 mA

for dual LEDs

SSL3252

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 1 — 7 July 2011

6 of 30

SSL3252

NXP Semiconductors

Photo flash LED driver

7.3 Operational modes

7.3.1 Shut-down mode

To enter the Shut-down mode, all control pins, IF_SEL, EN1 function of SCL/EN1, EN2

function of SDA/EN2, and TORCH, must be LOW. In this mode, the internal circuitry of the

device is turned off to guarantee a shut-down current of less than 1 A. The PMOS switch

of the converter is conducting, and the NMOS is set to high-impedance. To avoid current

leakage into the LED, the current source circuitry for both the main LED and the indicator

LED are switched to high-impedance.

7.3.2 Standby mode

The device only enters Standby mode in I²C mode when pin IF_SEL is HIGH and the

outputs are not active. In Standby mode, part of the internal circuitry of the device remains

on, but the converter is not switching. To avoid current leakage into the LED, the current

source circuitry for both the main LED and the indicator LED are switched to

high-impedance. In this mode, I²C communication with the device is possible.

7.3.3 Switching between Standby mode and Shut-down mode

When using the I²C interface, the lowest power mode is the Standby mode. To further

reduce the power, switching to Direct enable mode allows the device to enter Shut-down

mode. When switching to and from the Direct enable interface, the I²C lines have to be

switched LOW to avoid that they are interpreted as EN1 and EN2.

When IF_SEL is switched HIGH, the I²C lines may still be LOW. After the SDA lines and

the SCL lines have become HIGH, the bus free time has to be respected, as is specified in

the I²C-bus timing specifications. I²C communication cannot be started until at least

350 s after the IF_SEL line is switched HIGH.

When switching from Standby mode to Shut-down mode, the I²C lines need to be set

LOW before the IF_SEL line is set LOW, or at least within 5 s after that, to avoid the

I²C levels being interpreted as EN1 and EN2, which may cause the LEDs to be lit.

Shut-down/

Torch mode

Shut-down/

Torch mode

minimum

350 µs

2

IF_SEL

I C mode/Standby mode

maximum

5 µs

SDA/EN2

SCL/EN1

START

condition

STOP

condition

014aaa305

Fig 5. Switching between Standby mode and Shut-down mode

SSL3252

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 1 — 7 July 2011

7 of 30

SSL3252

NXP Semiconductors

Photo flash LED driver

7.3.4 Torch mode

The Torch mode allows the main LED to be switched on at a lower LED current setting

without timing limitations. Torch mode can be selected by connecting pin TORCH to

HIGH. Pin TORCH is a debounced input. This allows the pin to be directly connected to a

mechanical switch. The debouncing circuit is active during both the LOW-to-HIGH and the

HIGH-to-LOW transitions. It uses a time constant of typically 9 ms.The main LEDs will

light to the set torch current level. The TORCH pin has an internal 350 k pull-down

resistor.

In I²C mode, the LED current is defined by bits D[2:0] in the current set register. The torch

current can be set between 20 mA and 160 mA. The same bits are also used for Assist

light mode. For details see Table 5 and Figure 4.

When using the Direct enable mode, the default torch current values are used. When only

one LED is used, the torch current will be set to a default level of 80 mA. For two LEDs

this value is 40 mA. The EN1 and EN2 signals have higher priority than the TORCH pin

signal. For details see Table 4 and Figure 3.

Figure 6 shows the current register setting for the torch.

I

(mA)

LED

160

140

120

100

80

(1)

(2)

(3)

60

40

20

register

value

0

1

2

3

4

5

6

7

014aaa306

(1) I²C level

(2) Direct enable level; one LED

(3) Direct enable level; two LEDs

Fig 6. Torch and Assist light LED current levels

SSL3252

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 1 — 7 July 2011

8 of 30

SSL3252

NXP Semiconductors

Photo flash LED driver

7.3.5 Assist light mode

The Assist light mode allows the main LED to be switched on at a lower LED current

setting, without any timing limitations. The Assist light mode can be selected in both I²C

and Direct enable modes.

In I²C mode, the LED current is defined by bits D[2:0] in the current set register. The

Assist light current value can be set between 20 mA and 160 mA. The same bits are also

used for Torch mode. Entering Assist light mode is possible if bits D[1:0] from the control

register are set to 10 and bit D3 from the same register is set to 1.

When using the Direct enable mode, the default Assist light current values are used.

When only one LED is used, the Assist light current will be set to a default level of 80 mA.

For two LEDs this value is 40 mA. The state of the EN1 function of the SCL/EN1 pin must

be LOW and the state of the EN2 function of the SDA/EN2 pin HIGH to enter Assist light

mode (see Table 4). Figure 6 shows the current register setting for the Assist light.

7.3.6 Flash mode

The Flash mode allows the main LEDs to be used at high current settings. The Flash

mode current can be set to up to 500 mA in both the I²C mode and Direct enable mode.

In I²C mode, the current is defined by bits D[7:4] in the current set register. When two

LEDs are used and the register is set for more than 400 mA, the maximum current is

clipped to 400 mA. Generating the Flash mode can be done in the following three ways:

• software controlled

• edge sensitive strobe

• level sensitive strobe

When using the I²C software controlled flash, the bits in the control register D[1:0] = 11,

D2 = 0 and D3 = 1 must be set and the timing of the flash is determined by the value of

the bits D[3:0] in the indicator/timer register. Figure 7 shows the software controlled flash

operation.

2

I C

command

SDA/SCL

output on bit D3

register 04h

I

LED

014aaa655

Fig 7. I²C Flash mode

The strobe signal coming directly from the host, or camera processor, can be used to

avoid I²C latency for the flash. To select Strobe flash mode, bit D2 in the control register

must be set to 1. In I²C mode the STRB function of the STRB/2LED pin has an internal

SSL3252

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 1 — 7 July 2011

9 of 30

SSL3252

NXP Semiconductors

Photo flash LED driver

pull-down resistor of 350 k, and can be either level sensitive or edge sensitive,

depending on the value of the bit D5 in the control register (0 = edge sensitive,

1 = level sensitive).

When using the level sensitive strobe, the flash operates as long as the strobe signal is

active, or until the time limit set by the ‘flash timer’ bits in the indicator/timer register is

reached. This will generate time-out fault. Figure 8 shows the level sensitive strobe flash

operation.

output on bit D3

register 04h

STRB

I

LED

014aaa656

Fig 8. Level sensitive strobe

When the edge sensitive strobe signal is used, the flash is activated at the positive edge

of the STRB function of the STRB/2LED pin, and the flash operation time will be defined

from the timer register value. Figure 9 shows the edge sensitive strobe flash operation.

output on bit D3

register 04h

STRB

I

LED

014aaa654

Fig 9. Edge sensitive strobe

After the flash pulse in all three flash modes, the output ON bit is automatically cleared.

In Direct enable mode, the flash current will be set to a default level. When only one LED

is used, the flash current will be set to a default level of 500 mA. For two LEDs, this value

is 320 mA. Entering Flash mode in Direct enable mode can be done by switching the level

to HIGH on both the EN1 and EN2 functions of the SCL/EN1 and SDA/EN2 pins (Table 4).

The LED will stay lit in Flash mode for as long as the enable pins are set to Flash mode,

but limited to a maximum of 850 ms by the time-out timer. Figure 10 shows the current

levels for the flash in both the I²C and the Direct enable use case. More details on flash

timing are given in Section 7.4.1.

SSL3252

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 1 — 7 July 2011

10 of 30

SSL3252

NXP Semiconductors

Photo flash LED driver

I

(mA)

LED

(2)

500

480

440

400

360

320

280

(1)

(3)

(4)

240

200

register

value

0

1

2

3

4

5

6

7

8

9 10 11 12 13 14 15

014aaa308

(1) I²C level for one LED.

(2) Direct enable default level for one LED.

(3) I²C maximum level for two LEDs.

(4) Direct enable default level for two LEDs.

Fig 10. Flash mode LED current levels

7.3.7 Indicator

The indicator LED is connected between the dedicated indicator LED current output pin

(I_IND) and GND. Internally, a linear current source controls the indicator LED current to

the required current level.

In I²C interface mode, the indicator LED current can be set between 2.5 mA and 10 mA by

bits D[7:6] of the indicator/timer register.

When using the Direct enable mode, the indicator current is set to a default level of

2.5 mA.

Figure 11 shows the LED current levels for the indicator in both the I²C and the Direct

enable use case.

SSL3252

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 1 — 7 July 2011

11 of 30

SSL3252

NXP Semiconductors

Photo flash LED driver

I

(mA)

I_IND

10

7.5

5

Direct enable

2.5

register

value

0

1

2

3

014aaa309

Fig 11. Indicator LED current levels

7.4 Protection circuits

There are several integrated protection circuits that protect the device and the application

against defects. Some of the protection circuits trigger the corresponding bit in the

fault and info register. In I²C mode, the external logic can read out the status of the

protection circuits to determine what fault has occurred, and decide on the proper action

to take. In Direct enable mode, the status register cannot be read out, but the protection

circuits are still functional. In I²C mode the faults are cleared automatically by reading the

fault and info register. In Direct enable mode the faults are cleared when the EN1 function

of SCL/EN1, EN2 function of SCL/EN2 and TORCH pins are set to LOW.

7.4.1 Time-out protection

A time-out protection function is used to avoid main LED overloading during flash. The

timer is started when the Flash mode is activated by the software, or by hardware strobe

signals in I²C mode, or by the signals EN1 and EN2 in Direct enable mode.

The time-out protection is active in I²C level sensitive strobe Flash and Direct enable

modes. When using I²C level sensitive strobe Flash mode the time-out protection is

triggered when the STRB signal is active longer than the time set by the ‘flash timer’ bits in

indicator/timer register. In Direct enable mode, the default time limit is used as a trigger for

this protection. If the EN1/EN2 signals are active (HIGH) longer than the default limit of

850 ms, the time-out protection is triggered. In case of a time-out fault the IC will stop

switching and go into Fault mode. The fault and info register is set accordingly to flag a

fault condition.

SSL3252

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 1 — 7 July 2011

12 of 30

SSL3252

NXP Semiconductors

Photo flash LED driver

7.4.2 Overtemperature protection

If the chip temperature exceeds its limit (T_otp, see Table 9), the SSL3252 will stop

switching and enter Fault mode.

When an overtemperature situation is encountered, the fault and info register is set

accordingly to flag a fault condition. If the chip temperature drops below the T_{otp(hys) level}

and the fault register is cleared, the SSL3252 can operate normally.

7.4.3 Overvoltage protection

If the output voltage (V_O) exceeds its limit (V_O(ovp), see Table 9), the SSL3252 will stop

switching and enter Fault mode. Overvoltage protection will be triggered when there is no

LED connected to LED pin (open), or no capacitor connected to VO pin (open).

If the overvoltage protection is triggered, the fault and info register is set accordingly to

flag a fault condition.

7.4.4 Short-circuit protection

The output is short-circuit protected to avoid device and battery overloading. If the LED is

shorted to GND (voltage on LED drops below 1.2 V) due to a main LED, or application

failure, the SSL3252 will stop switching and enter Fault mode.

If the short-circuit protection is triggered, the fault and info register is set accordingly to

flag a fault condition.

7.4.5 Broken coil detection

To avoid device and battery overloading from high peak currents, the device is equipped

with broken coil peak current protection. This protection will be triggered when the core of

the coil is broken and the inductance of the coil drops below 800 nH (25 %). The broken

coil detection is done at the beginning of the ramp-up of the LED current. In case of

broken coil detection, the SSL3252 will stop switching and go in Fault mode.

If the broken coil protection is triggered, the fault and info register is set accordingly to flag

a fault condition.

7.4.6 Indicator output protection

The I_IND output is short-circuit and open-circuit protected to detect the fault condition.

In case I_IND is shorted (V_{I_IND}is less than 1.2 V) to GND or open (I_IND current is lower

than 1.25 mA), the SSL3252 will only stop the indicator LED current source. The rest of

the device will remain functional.

If the indicator output protection is triggered, the fault and info register is set accordingly to

flag a fault condition.

7.4.7 Undervoltage lockout

As a result of a low input voltage, the input voltage can drop too low to guarantee normal

operation. When the input voltage has dropped below the undervoltage lockout level, the

device switches to Fault mode stopping the switching completely. Start-up in I²C mode is

only possible by crossing the start-up level (V_I(UVLO)+ V_hys(UVLO)) and if the TORCH pin is

LOW, see Table 9. Start-up in Direct enable mode is only possible by crossing the start-up

level and if EN1 function of SCL/EN1, EN2 function of SDA/EN2 and TORCH pins are

SSL3252

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 1 — 7 July 2011

13 of 30

SSL3252

NXP Semiconductors

Photo flash LED driver

LOW. Recovering from this error results in the reset of all register settings. This protection

cannot be read out in the status register. Figure 12 shows the UVLO and trigger points

and hysteresis.

50 mV to 150 mV

V

I

UVLO (hysteresis)

UVLO

2.3 V to 2.5 V

014aaa310

Fig 12. UVLO levels and hysteresis V_I

7.5 Soft ramp-up/ramp-down of LED current

The device is equipped with a soft ramp-up/ramp-down circuit to avoid battery

overloading. When entering the Torch mode, Assist light mode or Flash mode, when

switching back to Standby mode or Shut-down mode, or just going from one current mode

to another (e.g., Torch mode to Flash mode), the soft start circuit will slowly increase or

decrease the output current until the required LED current has been reached. The

maximum total ramp-up time will be 1 ms including the 150 s wake-up time for going

from 0 mA to the maximum current of 500 mA and the maximum ramp-down time of

770 s for going from 500 mA to 0 mA. The ramp-up/ramp-down time depends on the

LED current setting.

770 µs

500 mA

I

LED

150 µs

0 A

wake-up

ramp-up

ramp-down

shut-down

014aaa311

Fig 13. Maximum soft ramp-up and ramp-down time (for 500 mA LED current)

7.6 Peak current limit

The device is equipped with a peak current limit function to avoid saturation of the

inductor. This circuit limits the peak inductor currents to the value set in the control register

(04h bits D[7:6]). In Direct enable mode the default current limit value is 1.75 A. No

protection is activated.

SSL3252

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 1 — 7 July 2011

14 of 30

SSL3252

NXP Semiconductors

Photo flash LED driver

7.7 Start-up sequence

When I²C mode is selected (IF_SEL is HIGH) and the voltage on the VIN pin is rising to a

level higher than the Power-On Reset (POR) value (POR level is typically 2.0 V) all

registers are set to their reset state. After the registers are set, the device enters Standby

mode and waits for I²C commands.

If the Direct enable mode is selected (IF_SEL is low), POR is detected, and pins EN1

function of SCL/EN1, EN2 function of SDA/EN2, and TORCH are set to LOW, the device

will stay in Shut-down mode. When activity is detected on one of the control pins (EN1

function of SCL/EN1, EN2 function of SDA/EN2 or TORCH), the SSL3252 will start to

operate using the default settings. When the activity ends (all control pins are LOW) the

device will go back to Shut-down mode.

7.8 LED detection

There is an internal circuit integrated into the SSL3252, which is capable of detecting the

number of LEDs connected in series to the LED output, and automatically selecting the

right default current settings. The number of LEDs is detected every time the LED is

ramping up. At an LED current of 80 mA the voltage at the LED output is compared to the

reference level of 4.35 V plus the offset set by bits D[5:4] in the indicator/timer register. If

the measured voltage is higher than the reference level, this is interpreted as two LEDs

connected in series at the LED pin and the device changes all current settings to the dual

LED default value. If the voltage is lower than the reference level, the single LED current

settings are selected.

In I²C mode, bit D3 in the fault and info register is set according to the detected amount of

LEDs. In Direct enable mode, the 2LED function of the STRB/2LED pin is used to indicate

the number of detected LEDs. The STRB/2LED pin is an open-drain output pin in Direct

enable mode with a maximum sink current of 1 mA. The 2LED function of the STRB/2LED

pin will only signal the number of LEDs in Flash mode. The signal on the 2LED function of

the STRB/2LED pin will be active during the flash period from the moment of the detection

(80 mA LED current) until the moment the LED current is back to 0 mA. In all other

operating modes, the 2LED function of the STRB/2LED pin will be high-impedance.

In I²C mode, LED detection can be disabled by setting bit D3 in the current set register to

0. In this case, the number of LEDs can only be set via the I²C-bus by writing the required

value to bit 3 from the fault and info register, which results in the corresponding default

currents being set.

When operating in Assist light mode or Torch mode and with the LED detection enabled,

the LED output will always first ramp-up to 80 mA and then ramp-up or ramp-down to the

value set by the current register.

7.9 I²C-bus protocol

The I²C interface is a 2-wire serial interface developed by NXP Semiconductors to

communicate between different ICs or modules. The two wires are a Serial DAta line

(SDA) and a Serial Clock Line (SCL). Both lines must be connected to a positive supply

via a pull-up resistor when connected to the output stages of a device. Data transfer may

only be initiated when the bus is not busy. The SSL3252 I²C-bus characteristic is the

400 kbit/s Fast-mode I²C-bus from the I²C-bus specification.

SSL3252

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 1 — 7 July 2011

15 of 30

SSL3252

NXP Semiconductors

Photo flash LED driver

Remark: For more details on the I²C-bus standard, refer to the document

UM10204, “I²C-bus specification and user manual”

(www.nxp.com/documents/user_manual/UM10204.pdf).

The following text describes the protocols used by the SSL3252 for the read and write

sequences. The read sequence may use a repeated START condition during the

sequence, to stop the bus being released during the communication. The sequences can

be used to read or write only one data byte, or to read or write a sequence of data bytes.

After a START condition, a valid hardware address must be sent to the SSL3252 followed

by a subaddress and n data bytes. See Figure 14 and Figure 15 below. For the format and

the timing of the START condition (S), the STOP condition (P) and the Acknowledge bit

(A), refer to the user manual UM10204.

S

slave address

W

A

subaddress n

A

th

n

register

P

S = START condition

P = STOP condition

A = Acknowledge

from master to slave

from slave to master

N = Not Acknowledged

014aaa316

Fig 14. I²C write data transfer format

S

slave address

W

R

A

subaddress n

A

th

n

register

N

P

S = START condition

P = STOP condition

A = Acknowledge

from master to slave

from slave to master

N = Not Acknowledged

014aaa317

Fig 15. I²C read data transfer format

7.9.1 Addressing

Each SSL3252 in an I²C-bus system is activated by sending a valid slave address to the

device. The slave address always has to be sent as the first byte after the START

condition in the I²C-bus protocol. See Figure 16.

MSB

0

LSB

0

R

1

0

W

014aaa318

Fig 16. I²C slave address

SSL3252

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 1 — 7 July 2011

16 of 30

SSL3252

NXP Semiconductors

Photo flash LED driver

There is one address byte required since 7-bit addresses are used. The last bit of the

address byte is the read/write bit and should always be set according to the required

operation. This 7-bit address is 0110 000b (30h). The combination with the LSB R/W bit

gives a write address of 60h and a read address of 61h.

The second byte sent to the SSL3252 is the subaddress of the specific register.

7.9.2 Data

After the subaddress the data bytes are sent. The definition of the data transfer is given in

Figure 14 and Figure 15. After each data byte an acknowledge is given and the

subaddress is automatically incremented to the next subaddress.

A description of the data that can be programmed in the registers is given in Table 6.

7.9.3 Register map

Table 6.

Description of registers

Legend: * default reset register value.

Address Register Bit

Symbol

Access Value

Description

00h

Design info

7 to 4 Man_ID

R

0100*

0001*

0000*

0000

0001

:

Manufacturer ID

3 to 0 Model_ID

Model ID

01h

Version control 7 to 4 Reserved

3 to 0 Design version

Reserved for future use

Design version 1

Design version 2

:

1111

00*

01

Design version 16

02h

Indicator/timer 7 to 6 Indicator

current

R/W

Indicator LED current 2.5 mA (default)

Indicator LED current 5 mA

Indicator LED current 7.5 mA

Indicator LED current 10 mA

No offset (default)

10

11

5 to 4 Vref offset

3 to 0 Flash timer

00*

01

Offset = V_ref+ 0.3 V

Offset = V_ref 0.3 V

Offset = V_ref+ 0.6 V

Software flash timer value 100 ms

Software flash timer value 150 ms

:

10

11

0000

0001

:

1111*

Software flash timer value 850 ms (default)

SSL3252

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 1 — 7 July 2011

17 of 30

SSL3252

NXP Semiconductors

Photo flash LED driver

Table 6.

Description of registers …continued

Legend: * default reset register value.

Address Register

Bit

Symbol

Access Value

Description

03h

Current set

7 to 4 Flash^[1]

R/W

0000

0001

:

Flash current 200 mA

Flash current 220 mA

:

0110*

:

Flash current 320 mA (default dual LEDs)

:

1111

1*

Flash current 500 mA (default single LED)

3

LED detection

enable

R/W

Enabled number of LED detection

(default enabled)

2 to 0 Assist/Torch

current

000

Assist/Torch current 20 mA

001*

Assist/Torch current 40 mA

(default two LEDs)

:

011

Assist/Torch current 80 mA

(default one LED)

:

111

00

01

10*

11

1*

Assist/Torch current 160 mA

Coil peak current limit 1.25 A

Coil peak current limit 1.5 A

Coil peak current limit 1.75 A (default)

Coil peak current limit 2.00 A

04h

Control

7 to 6 Coil peak

R/W

5

4

3

2

Strobe signal

Torch mode

Output ON

Strobe

R/W

Strobe signal usage (0 = edge sensitive,

1 = level sensitive)

1*

0*

Torch mode allowed in Standby mode

(1 = allowed)

Turn ON outputs Indicator mode,

Assist light mode or Flash mode (1 = ON)

R/W

1*

00*

01

10

11

0*

-

Strobe signal mode (1 = enabled)

Torch mode (default)

Indicator mode

1 to 0 Output mode

Assist light mode

Flash mode

05h

Fault and info

7

6

5

4

3

OVP

R

Overvoltage protection (1 = fault)

Short-circuit LED (1 = fault)

Overtemperature (1 = fault)

Time-out (1 = fault)

Short circuit

Over temp

Timeout

R

Amount LEDs

R/W

Amount of LEDs on LED (0 = one LED,

1 = two LEDs)

2

1

0

Indicator LED

Broken coil

Reserved

R

0*

Short or open circuit on I_IND (1 = fault)

Broken coil (1 = fault)

Reserved for future use

[1] For register settings above 400 mA and dual LED detected, the output LED current will be limited to 400 mA.

SSL3252

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 1 — 7 July 2011

18 of 30

SSL3252

NXP Semiconductors

Photo flash LED driver

8. Limiting values

Table 7.

Limiting values

In accordance with the Absolute Maximum Rating System (IEC 60134).

Symbol

V_I

Parameter

Conditions

Min

0.5

-

Max

+5.5

V_I

Unit

V

input voltage

on pin VIN

V_{SDA_EN2}

V_{SCL_EN1}

V_{STRB_2LED}

V_{IF_SEL}

V_TORCH

V_{I_IND}

V_O(LED)

V_O

voltage on pin SDA/EN2

voltage on pin SCL/EN1

voltage on pin STRB/2LED

voltage on pin IF_SEL

voltage on pin TORCH

voltage on pin I_IND

LED output voltage

output voltage

V

V_I

V

V_I

V

V_I

V

V_I

V

V_I

V

pin LED

pin VO

+10^[1]

0.8

V

V_LX

voltage on pin LX

V

P_tot

total power dissipation

junction temperature

ambient temperature

storage temperature

T_amb= 85 C

W

C

V

T_j

40

55

-

+150

+85

+150

2000

T_amb

T_stg

IC

V_ESD

electrostatic discharge

voltage

human body model

according to

JESD22-A114-E

charged-device

-

500

V

model according to

JESD22-C101-A

[1] Tolerant to the specified maximum voltage while operating. Do not apply voltages externally; this may

cause permanent damage to the device.

9. Thermal characteristics

Table 8.

Thermal characteristics

Parameter

thermal resistance from junction mounted on dedicated

to ambient

4 layer PCB in free air^[1]

Symbol

Conditions

Typ

Unit

R_th(j-a)

83

K/W

[1] The junction to ambient thermal resistance is dependent on board layout, PCB material application and

environmental conditions.

SSL3252

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 1 — 7 July 2011

19 of 30

SSL3252

NXP Semiconductors

Photo flash LED driver

10. Characteristics

Table 9.

Characteristics

V_I= 2.7 V to 5.5 V; T_amb= 40 C to +85 C, unless otherwise specified.

Symbol

General voltage levels

V_Iinput voltage

Parameter

Conditions

Min

Typ^[1]Max

Unit

pin VIN

2.7

2.5

-

5.5

V

[2]

V_{I(extnd)(VIN)}extended input voltage on

pin VIN

V_I(UVLO)

V_hys(UVLO)

V_th

undervoltage lockout

input voltage

V_Ifalling

V_Irising

2.3

50

2.4

2.5

V

undervoltage lockout

hysteresis voltage

100

4.35

150

4.45

mV

V

threshold voltage

on pin LED for single and dual LED

detection; no offset;

4.25

register value 00

General current levels

I_stb

standby current

Standby and Fault modes

Shut-down mode

-

10

1

A

I_sd

shutdown current

I_lmtr(IM)(LX)

peak current limiter current

on pin LX

inductor peak current limiter

register value 00

1.125

1.35

1.575

1.8

1.25

1.5

1.375

1.65

1.925

2.2

A

register value 01

register value 10

1.75

2.0

register value 11

High power LED parameters

V_O(LED)

LED output voltage

pin LED

2.8

-

8.5

1.2

V

short-circuit protection level on

pin LED

V_hr

headroom voltage

current source; headroom voltage;

V_hr= V_O V_LED; in Boost mode,

V_I= 3.6 V

-

300

-

mV

I_LED

LED current

pin LED; I²C mode; single LED

pin LED; I²C mode; dual LED

from 20 mA to 180 mA

20

-

500

400

20

mA

%

-

I_LED

LED current variation

-

from 200 mA to 500 mA

-

10

%

V_O(ovp)

overvoltage protection output pin VO

voltage

9

9.5

10

V

Indicator LED parameters

I_{I_IND}

current on pin I_IND

IF_SEL = 1 (I²C mode)

2.5

-

10

-

mA

[3]

IF_SEL = 0 (Direct enable mode)

-

2.5

-

open-circuit protection level at pin

I_IND

1.25

V_{I_IND}

voltage on pin I_IND

1.2

-

V_I 0.01 V

short-circuit protection level at pin

I_IND

1.2

V

I_{I_IND}

current variation on pin I_IND

-

20

%

SSL3252

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 1 — 7 July 2011

20 of 30

SSL3252

NXP Semiconductors

Photo flash LED driver

Table 9.

Characteristics …continued

V_I= 2.7 V to 5.5 V; T_amb= 40 C to +85 C, unless otherwise specified.

Symbol

Parameter

Conditions

Min

Typ^[1]Max

Unit

Power MOSFETs

R_DSon

drain-source on-state

resistance

NMOS

PMOS

-

240

400

-

m

Timing

f_sw

switching frequency

time-out time

1.85

-

2.0

2.15

-

MHz

ms

t_to

Flash mode; the absolute value can

be set with I²C

850

t_to

time-out time variation

soft start time

-

7.5

%

t_start(soft)

from Standby mode or Shut-down

mode to maximum current on LED

(from 0 mA to 500 mA)

1000

s

t_stop(soft)

soft stop time

from maximum current on LED (from

500 mA to 0 mA) to Standby mode

or Shut-down mode

-

825

s

I²C interface

V_IL

LOW-level input voltage

HIGH-level input voltage

LOW-level output voltage

SCL clock frequency

SCL/SDA

0

-

0.54

V_I

V

V_IH

V_OL

f_SCL

SCL/SDA

1.26

0

V

LOW on SDA; I_sink= 3 mA

0.4

400

V

0

kHz

2LED function of STRB/2LED

V_OL

I_OH

LOW-level output voltage

HIGH-level output current

I_sink= 1 mA; LOW state

HIGH state

0

-

0.4

1

V

A

SCL/EN1, SDA/EN2, IF_SEL, STRB function of STRB/2LED, TORCH

V_IL

LOW-level input voltage

HIGH-level input voltage

LOW - digital input voltage

HIGH - digital input voltage

0

-

0.54

V_I

V

V_IH

1.26

-

V

R_pd(int)

internal pull-down resistance pins TORCH, STRB function of

STRB/2LED (only in I²C mode),

350

-

k

SCL/EN1, SDA/EN2 (only in Direct

enable mode)

t_degl(TORCH)deglitch time on pin TORCH

6.3

9

11.7

ms

Temperature

T_otp

overtemperature protection

trip

temperature rising

temperature falling

-

150

20

-

C

T_otp(hys)

overtemperature protection

trip hysteresis

[1] All typical values are measured at T_amb= 25 C and V_I= 3.6 V.

[2] When operating in extended input voltage range, the device will be fully functional but has a reduced performance specification on

certain parameters. An extended input voltage range is entered when the input voltage is dropping below 2.7 V, assuming the device is

not in undervoltage lockout mode.

[3] When operating in Direct enable mode, the device will apply a default current setting. See Section 7.3 for details. The pin IF_SEL should

then be connected to GND.

SSL3252

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 1 — 7 July 2011

21 of 30

SSL3252

NXP Semiconductors

Photo flash LED driver

11. Application information

11.1 Input capacitor

For good input voltage decoupling, a low ESR ceramic capacitor is highly recommended.

A 4.7 F (X5R/X7R) 6.3 V is the minimum recommended value. Since the input capacitor

is supplying the input ripple current, a larger capacitor will improve both the transient

behavior of the regulator and the EMI behavior of the power supply. Taking capacitor DC

bias and temperature de-rating specifications into account, a 10 F (X5R/X7R) is

preferred. Although increasing component count, a smaller capacitor of 100 nF

(X5R/X7R) placed in parallel to the input capacitor will also improve EMI behavior.

11.2 Output capacitor

The output capacitor supplies the current into the main LED, while the inductor is being

charged, and it also ensures loop stability. The minimum capacitance for stable loop

operation would be 4.7 F, but taking capacitor DC bias and temperature de-rating

specifications into account, a low ESR ceramic capacitor of 10 F (X5R/X7R) is highly

recommended. A higher value of capacitance will improve output current ripple, while

maintaining loop stability. Typically the SSL3252 overvoltage limit on pin VO is at 9.5 V,

and the rated voltage of the output capacitor should be at least 10 V.

11.3 Inductor

The device has been designed to operate well with inductance values between 1.5 H

and 3.3 H, in order to optimize for solution size. In a typical high current dual flash LED

application a 2.2 H inductance is recommended. The inductor’s saturation current should

be greater than or equal to the inductor peak current limiter current, which is a typical

1.75 A. During normal operation, it is recommended to keep the inductor peak current

below this value. The copper losses and magnetic hysteresis losses in the inductor also

contribute to the total system losses.

11.4 PCB layout

It is essential to have a good circuit layout in order to maximize efficiency and minimize

EMI disturbance. The circuit topology uses an inductor, which is often seen as a main

source of EMI disturbance, but any loop of wire carrying a current is essentially an

electromagnet, whose field strength is proportional to the current. Careful circuit layout is

therefore very important, keeping loop areas small and minimizing the magnetic flux. Due

to the way a boost converter operates, there are two power states. One state when the

internal NMOS switch is ON, and one when the NMOS switch is OFF. During each state

there will be a current loop made by the power components that are conducting. The input

and output capacitors must be arranged in such a way on the SSL3252 that during each

of the two states the current loop is conducting in the same direction. This prevents phase

reversal of the magnetic field, and reduces radiated EMI. The current loop area should be

kept small by placing the power components as close as possible to the SSL3252. Use

ground planes to keep the loop areas to a minimum.

SSL3252

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 1 — 7 July 2011

22 of 30

SSL3252

NXP Semiconductors

Photo flash LED driver

Priority should be given for the output capacitor to be positioned as close as possible to

the VO and PGND nodes of the SSL3252. Since large currents will flow from input

capacitor to the inductor and not to the VIN pin of the SSL3252, it is wise to locate the

input capacitor near the inductor. The VIN pin should be star-connected to the positive

pad of the input capacitor.

PGND and GND of the SSL3252 should be directly connected to each other. Place the

ground connection of the output capacitor as close as possible to the PGND pin of the

SSL3252.

The preferred minimum trace width for the high current width is 15 mm/A.

SSL3252

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 1 — 7 July 2011

23 of 30

SSL3252

NXP Semiconductors

Photo flash LED driver

12. Package outline

WLCSP12: wafer level chip-size package; 12 bumps; 1.58 x 2.06 x 0.6 mm

SSL3252UK

D

B

A

bump A1

index area

A

2

E

A

1

detail X

e

1

C

M

∅ v

∅ w

C

A

B

e

b

y

M

D

e

C

B

A

e

2

1/2 e

1

2

3

X

0

1

2 mm

scale

DIMENSIONS (mm are the controlling dimensions)

A

UNIT

A

2

b

D

E

e

1

e

2

v

w

y

1

max

0.26 0.38 0.34 1.60 2.08

0.22 0.34 1.55 2.03

mm

0.64

0.5

1

1.5

0.01 0.04 0.02

0.30

REFERENCES

JEDEC JEITA

OUTLINE

VERSION

EUROPEAN

PROJECTION

ISSUE DATE

IEC

07-11-19

07-11-23

SSL3252UK

Fig 17. Package outline SSL3252UK (WLCSP12)

SSL3252

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 1 — 7 July 2011

24 of 30

SSL3252

NXP Semiconductors

Photo flash LED driver

13. Soldering of WLCSP packages

13.1 Introduction to soldering WLCSP packages

This text provides a very brief insight into a complex technology. A more in-depth account

of soldering WLCSP (Wafer Level Chip-Size Packages) can be found in application note

AN10439 “Wafer Level Chip Scale Package” and in application note AN10365 “Surface

mount reflow soldering description”.

Wave soldering is not suitable for this package.

All NXP WLCSP packages are lead-free.

13.2 Board mounting

Board mounting of a WLCSP requires several steps:

1. Solder paste printing on the PCB

2. Component placement with a pick and place machine

3. The reflow soldering itself

13.3 Reflow soldering

Key characteristics in reflow soldering are:

• Lead-free versus SnPb soldering; note that a lead-free reflow process usually leads to

higher minimum peak temperatures (see Figure 18) than a PbSn process, thus

reducing the process window

• Solder paste printing issues, such as smearing, release, and adjusting the process

window for a mix of large and small components on one board

• Reflow temperature profile; this profile includes preheat, reflow (in which the board is

heated to the peak temperature), and cooling down. It is imperative that the peak

temperature is high enough for the solder to make reliable solder joints (a solder paste

characteristic) while being low enough that the packages and/or boards are not

damaged. The peak temperature of the package depends on package thickness and

volume and is classified in accordance with Table 10.

Table 10. Lead-free process (from J-STD-020C)

Package thickness (mm) Package reflow temperature (C)

Volume (mm³)

< 350

260

350 to 2000

260

> 2000

260

< 1.6

1.6 to 2.5

> 2.5

260

250

245

250

245

Moisture sensitivity precautions, as indicated on the packing, must be respected at all

times.

Studies have shown that small packages reach higher temperatures during reflow

soldering, see Figure 18.

SSL3252

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 1 — 7 July 2011

25 of 30

SSL3252

NXP Semiconductors

Photo flash LED driver

maximum peak temperature

= MSL limit, damage level

temperature

minimum peak temperature

= minimum soldering temperature

peak

temperature

time

001aac844

MSL: Moisture Sensitivity Level

Fig 18. Temperature profiles for large and small components

For further information on temperature profiles, refer to application note AN10365

“Surface mount reflow soldering description”.

13.3.1 Stand off

The stand off between the substrate and the chip is determined by:

• The amount of printed solder on the substrate

• The size of the solder land on the substrate

• The bump height on the chip

The higher the stand off, the better the stresses are released due to TEC (Thermal

Expansion Coefficient) differences between substrate and chip.

13.3.2 Quality of solder joint

A flip-chip joint is considered to be a good joint when the entire solder land has been

wetted by the solder from the bump. The surface of the joint should be smooth and the

shape symmetrical. The soldered joints on a chip should be uniform. Voids in the bumps

after reflow can occur during the reflow process in bumps with high ratio of bump diameter

to bump height, i.e. low bumps with large diameter. No failures have been found to be

related to these voids. Solder joint inspection after reflow can be done with X-ray to

monitor defects such as bridging, open circuits and voids.

13.3.3 Rework

In general, rework is not recommended. By rework we mean the process of removing the

chip from the substrate and replacing it with a new chip. If a chip is removed from the

substrate, most solder balls of the chip will be damaged. In that case it is recommended

not to re-use the chip again.

SSL3252

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 1 — 7 July 2011

26 of 30

SSL3252

NXP Semiconductors

Photo flash LED driver

Device removal can be done when the substrate is heated until it is certain that all solder

joints are molten. The chip can then be carefully removed from the substrate without

damaging the tracks and solder lands on the substrate. Removing the device must be

done using plastic tweezers, because metal tweezers can damage the silicon. The

surface of the substrate should be carefully cleaned and all solder and flux residues

and/or underfill removed. When a new chip is placed on the substrate, use the flux

process instead of solder on the solder lands. Apply flux on the bumps at the chip side as

well as on the solder pads on the substrate. Place and align the new chip while viewing

with a microscope. To reflow the solder, use the solder profile shown in application note

AN10365 “Surface mount reflow soldering description”.

13.3.4 Cleaning

Cleaning can be done after reflow soldering.

14. Abbreviations

Table 11. Abbreviations

Abbreviation

EMI

Description

ElectroMagnetic Interference

Equivalent Series Resistance

Integrated Circuit

ESR

IC

I/O

Input/Output

LED

Light Emitting Diode

MOSFET

NMOS

PCB

Metal-Oxide Semiconductor Field-Effect Transistor

N-type Metal-Oxide Semiconductor

Printed-Circuit Board

PDA

Personal Digital Assistant

P-type Metal-Oxide Semiconductor

Power-On Reset

PMOS

POR

PWM

RF

Pulse Width Modulation

Radio Frequency

15. Revision history

Table 12. Revision history

Document ID

Release date

20110707

Data sheet status

Change notice

Supersedes

SSL3252 v.1

Product data sheet

-

SSL3252

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 1 — 7 July 2011

27 of 30

SSL3252

NXP Semiconductors

Photo flash LED driver

16. Legal information

16.1 Data sheet status

Document status^[1][2]

Product status^[3]

Development

Definition

Objective [short] data sheet

This document contains data from the objective specification for product development.

This document contains data from the preliminary specification.

This document contains the product specification.

Preliminary [short] data sheet Qualification

Product [short] data sheet Production

[1]

[2]

[3]

Please consult the most recently issued document before initiating or completing a design.

The term ‘short data sheet’ is explained in section “Definitions”.

The product status of device(s) described in this document may have changed since this document was published and may differ in case of multiple devices. The latest product status

information is available on the Internet at URL http://www.nxp.com.

malfunction of an NXP Semiconductors product can reasonably be expected

16.2 Definitions

to result in personal injury, death or severe property or environmental

damage. NXP Semiconductors accepts no liability for inclusion and/or use of

NXP Semiconductors products in such equipment or applications and

therefore such inclusion and/or use is at the customer’s own risk.

Draft — The document is a draft version only. The content is still under

internal review and subject to formal approval, which may result in

modifications or additions. NXP Semiconductors does not give any

representations or warranties as to the accuracy or completeness of

information included herein and shall have no liability for the consequences of

use of such information.

Applications — Applications that are described herein for any of these

products are for illustrative purposes only. NXP Semiconductors makes no

representation or warranty that such applications will be suitable for the

specified use without further testing or modification.

Short data sheet — A short data sheet is an extract from a full data sheet

with the same product type number(s) and title. A short data sheet is intended

for quick reference only and should not be relied upon to contain detailed and

full information. For detailed and full information see the relevant full data

sheet, which is available on request via the local NXP Semiconductors sales

office. In case of any inconsistency or conflict with the short data sheet, the

full data sheet shall prevail.

Customers are responsible for the design and operation of their applications

and products using NXP Semiconductors products, and NXP Semiconductors

accepts no liability for any assistance with applications or customer product

design. It is customer’s sole responsibility to determine whether the NXP

Semiconductors product is suitable and fit for the customer’s applications and

products planned, as well as for the planned application and use of

customer’s third party customer(s). Customers should provide appropriate

design and operating safeguards to minimize the risks associated with their

applications and products.

Product specification — The information and data provided in a Product

data sheet shall define the specification of the product as agreed between

NXP Semiconductors and its customer, unless NXP Semiconductors and

customer have explicitly agreed otherwise in writing. In no event however,

shall an agreement be valid in which the NXP Semiconductors product is

deemed to offer functions and qualities beyond those described in the

Product data sheet.

NXP Semiconductors does not accept any liability related to any default,

damage, costs or problem which is based on any weakness or default in the

customer’s applications or products, or the application or use by customer’s

third party customer(s). Customer is responsible for doing all necessary

testing for the customer’s applications and products using NXP

Semiconductors products in order to avoid a default of the applications and

the products or of the application or use by customer’s third party

customer(s). NXP does not accept any liability in this respect.

16.3 Disclaimers

Limiting values — Stress above one or more limiting values (as defined in

the Absolute Maximum Ratings System of IEC 60134) will cause permanent

damage to the device. Limiting values are stress ratings only and (proper)

operation of the device at these or any other conditions above those given in

the Recommended operating conditions section (if present) or the

Characteristics sections of this document is not warranted. Constant or

repeated exposure to limiting values will permanently and irreversibly affect

the quality and reliability of the device.

Limited warranty and liability — Information in this document is believed to

be accurate and reliable. However, NXP Semiconductors does not give any

representations or warranties, expressed or implied, as to the accuracy or

completeness of such information and shall have no liability for the

consequences of use of such information.

In no event shall NXP Semiconductors be liable for any indirect, incidental,

punitive, special or consequential damages (including - without limitation - lost

profits, lost savings, business interruption, costs related to the removal or

replacement of any products or rework charges) whether or not such

damages are based on tort (including negligence), warranty, breach of

contract or any other legal theory.

Terms and conditions of commercial sale — NXP Semiconductors

products are sold subject to the general terms and conditions of commercial

sale, as published at http://www.nxp.com/profile/terms, unless otherwise

agreed in a valid written individual agreement. In case an individual

agreement is concluded only the terms and conditions of the respective

agreement shall apply. NXP Semiconductors hereby expressly objects to

applying the customer’s general terms and conditions with regard to the

purchase of NXP Semiconductors products by customer.

Notwithstanding any damages that customer might incur for any reason

whatsoever, NXP Semiconductors’ aggregate and cumulative liability towards

customer for the products described herein shall be limited in accordance

with the Terms and conditions of commercial sale of NXP Semiconductors.

Right to make changes — NXP Semiconductors reserves the right to make

changes to information published in this document, including without

limitation specifications and product descriptions, at any time and without

notice. This document supersedes and replaces all information supplied prior

to the publication hereof.

No offer to sell or license — Nothing in this document may be interpreted or

construed as an offer to sell products that is open for acceptance or the grant,

conveyance or implication of any license under any copyrights, patents or

other industrial or intellectual property rights.

Export control — This document as well as the item(s) described herein

may be subject to export control regulations. Export might require a prior

authorization from national authorities.

Suitability for use — NXP Semiconductors products are not designed,

authorized or warranted to be suitable for use in life support, life-critical or

safety-critical systems or equipment, nor in applications where failure or

SSL3252

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 1 — 7 July 2011

28 of 30

SSL3252

NXP Semiconductors

Photo flash LED driver

Non-automotive qualified products — Unless this data sheet expressly

states that this specific NXP Semiconductors product is automotive qualified,

the product is not suitable for automotive use. It is neither qualified nor tested

in accordance with automotive testing or application requirements. NXP

Semiconductors accepts no liability for inclusion and/or use of

own risk, and (c) customer fully indemnifies NXP Semiconductors for any

liability, damages or failed product claims resulting from customer design and

use of the product for automotive applications beyond NXP Semiconductors’

standard warranty and NXP Semiconductors’ product specifications.

non-automotive qualified products in automotive equipment or applications.

16.4 Trademarks

Notice: All referenced brands, product names, service names and trademarks

are the property of their respective owners.

In the event that customer uses the product for design-in and use in

automotive applications to automotive specifications and standards, customer

(a) shall use the product without NXP Semiconductors’ warranty of the

product for such automotive applications, use and specifications, and (b)

whenever customer uses the product for automotive applications beyond

NXP Semiconductors’ specifications such use shall be solely at customer’s

I²C-bus — logo is a trademark of NXP B.V.

17. Contact information

For more information, please visit: http://www.nxp.com

For sales office addresses, please send an email to: salesaddresses@nxp.com

SSL3252

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 1 — 7 July 2011

29 of 30

SSL3252

NXP Semiconductors

Photo flash LED driver

18. Contents

1

2

3

4

5

General description. . . . . . . . . . . . . . . . . . . . . . 1

12

Package outline. . . . . . . . . . . . . . . . . . . . . . . . 24

Features and benefits . . . . . . . . . . . . . . . . . . . . 1

Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Ordering information. . . . . . . . . . . . . . . . . . . . . 2

Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 2

13

13.1

13.2

13.3

13.3.1

13.3.2

13.3.3

13.3.4

Soldering of WLCSP packages . . . . . . . . . . . 25

Introduction to soldering WLCSP packages . 25

Board mounting . . . . . . . . . . . . . . . . . . . . . . . 25

Reflow soldering . . . . . . . . . . . . . . . . . . . . . . 25

Stand off. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Quality of solder joint . . . . . . . . . . . . . . . . . . . 26

Rework. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Cleaning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

6

6.1

6.2

Pinning information. . . . . . . . . . . . . . . . . . . . . . 3

Pinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Pin description . . . . . . . . . . . . . . . . . . . . . . . . . 3

7

7.1

7.2

7.2.1

7.2.2

7.3

7.3.1

7.3.2

7.3.3

Functional description . . . . . . . . . . . . . . . . . . . 4

Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Interface modes . . . . . . . . . . . . . . . . . . . . . . . . 4

Using the direct enable control. . . . . . . . . . . . . 5

Using the I²C control. . . . . . . . . . . . . . . . . . . . . 6

Operational modes . . . . . . . . . . . . . . . . . . . . . . 7

Shut-down mode . . . . . . . . . . . . . . . . . . . . . . . 7

Standby mode. . . . . . . . . . . . . . . . . . . . . . . . . . 7

Switching between Standby mode

14

15

Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . 27

Revision history . . . . . . . . . . . . . . . . . . . . . . . 27

16

Legal information . . . . . . . . . . . . . . . . . . . . . . 28

Data sheet status . . . . . . . . . . . . . . . . . . . . . . 28

Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Disclaimers . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . 29

16.1

16.2

16.3

16.4

17

18

Contact information . . . . . . . . . . . . . . . . . . . . 29

Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

and Shut-down mode . . . . . . . . . . . . . . . . . . . . 7

Torch mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Assist light mode . . . . . . . . . . . . . . . . . . . . . . . 9

Flash mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Protection circuits . . . . . . . . . . . . . . . . . . . . . . 12

Time-out protection. . . . . . . . . . . . . . . . . . . . . 12

Overtemperature protection . . . . . . . . . . . . . . 13

Overvoltage protection . . . . . . . . . . . . . . . . . . 13

Short-circuit protection . . . . . . . . . . . . . . . . . . 13

Broken coil detection . . . . . . . . . . . . . . . . . . . 13

Indicator output protection . . . . . . . . . . . . . . . 13

Undervoltage lockout . . . . . . . . . . . . . . . . . . . 13

Soft ramp-up/ramp-down of LED current . . . . 14

Peak current limit . . . . . . . . . . . . . . . . . . . . . . 14

Start-up sequence. . . . . . . . . . . . . . . . . . . . . . 15

LED detection. . . . . . . . . . . . . . . . . . . . . . . . . 15

I²C-bus protocol . . . . . . . . . . . . . . . . . . . . . . . 15

Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Register map . . . . . . . . . . . . . . . . . . . . . . . . . 17

7.3.4

7.3.5

7.3.6

7.3.7

7.4

7.4.1

7.4.2

7.4.3

7.4.4

7.4.5

7.4.6

7.4.7

7.5

7.6

7.7

7.8

7.9

7.9.1

7.9.2

7.9.3

8

Limiting values. . . . . . . . . . . . . . . . . . . . . . . . . 19

Thermal characteristics . . . . . . . . . . . . . . . . . 19

Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . 20

9

10

11

Application information. . . . . . . . . . . . . . . . . . 22

Input capacitor . . . . . . . . . . . . . . . . . . . . . . . . 22

Output capacitor . . . . . . . . . . . . . . . . . . . . . . . 22

Inductor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

PCB layout . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

11.1

11.2

11.3

11.4

Please be aware that important notices concerning this document and the product(s)

described herein, have been included in section ‘Legal information’.

For more information, please visit: http://www.nxp.com

For sales office addresses, please send an email to: salesaddresses@nxp.com

Date of release: 7 July 2011

Document identifier: SSL3252


型号：	SSL3252UK/C2,515
厂家：	NXP
描述：	SSL3252 - Photo flash LED driver
文件：	总30页 (文件大小：547K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

SSL3252UK/C2,515 [NXP]

相关型号：

SSL32F

SSL32_1

SSL32_10

SSL32_11

SSL32_13

SSL33

SSL33

SSL33

SSL33

SSL34

SSL34

SSL34