SP6683ER [SIPEX]
High Power LED Driver for Parallel Configuration; 高功率LED驱动器，用于并行配置
| 型号： | SP6683ER |
| 厂家： | 
SIPEX CORPORATION |
| 描述： | High Power LED Driver for Parallel Configuration |
| 文件： | 总10页 (文件大小：201K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
®
Preliminary
SP6683
High Power LED Driver for Parallel Configuration
FEATURES
■ Drives up to 8 WLEDS
VOUT
C1P
VIN
10
9
1
2
3
4
5
C2P
■ Low Profile Inductorless Regulator
■ 1x/1.5x Mode Charge Pump
■ 200mA Output Using 1µF Ceramic Caps
■ +2.7V to +5.5V Input Voltage Range
■ 0.9mA Quiescent Current
C1N
SP6683
8
GND
10 Pin DFN
7
VMODE
FB
C2N
6
EN/PWM
■ 1µA Shutdown Current
■ Built-in 1.2MHz Oscillator
Now Available in Lead Free Packaging
■ Programmable Output Current or Voltage
■ PWM Dimming Control via Enable Pin
APPLICATIONS
■ Mobile Phone
■ PDA
■ Digital Still Camera
■ Digital Camcorder
■ Palmtop Computer
■ Color LCD Module
■ Shutdown to Disconnect Output from Input
via Shutdown
■ Soft Start to limit In-Rush Current
■ Space Saving 10-pin 3 x 3mm DFN Package
DESCRIPTION
The SP6683 is a high power current regulated charge pump ideal for converting a Li-Ion
battery input for driving up to 8 white LED’s used in backlighting color displays. The SP6683
operates with an internal 1.2MHz clock, enabling the use of small external components.
Output current can be accurately regulated by modulating the switcher between the charge
pump and output capacitor. In shutdown mode, the SP6683 discharges the output to ground
and draws less than 1µA current. The SP6683 utilizes 1µF capacitors to deliver up to 200mA
current regulated WLED drive capability. The SP6683 is offered in 10-pin DFN or MSOP
package.
TYPICAL APPLICATION SCHEMATIC
®
C2
1µF
1
2
3
4
5
10
9
V
C2P
C1N
GND
C2N
OUT
SP6683
C1P
C4
1µF
White
LED
8
V
IN
C5
7
V
MODE
1µF
R1
R5
Lithium-Ion
6
C1
1µF
FB
EN/PWM
C3 0.1µF
R5
1M
ENABLE/PWM DIMMING
Date: 07/07/04
SP6683 White LEDs Driver for Parallel Configuration
© Copyright 2004 Sipex Corporation
1
ABSOLUTE MAXIMUM RATINGS
VIN, VMODE, VOUT and EN/PWM................. -0.3V to 6V
VIN - VOUT ........................................................... 0.7V
Output Current (IOUT) ...................................... 300mA
Power Dissipation per Package - 10-pin MSOP
(derate 8.84mW/°C above +70°C) ................. 720mW
Junction Temperature .................................... +125°C
Storage Temperature ...................... -65°C to +150°C
ESD Rating. ................................................ 2kV HBM
These are stress ratings only and functional operation of
the device at these ratings or any other above those
indicated in the operation sections of the specifications
below is not implied. Exposure to absolute maximum
rating conditions for extended periods of time may affect
reliability.
ELECTRICAL CHARACTERISTICS
Unless otherwise specified: VIN =+2.7V to +5.0V, C1=C2=C4=C5=1.0µF (Ceramic, ESR=0.03Ω) and TAMB =-40°C to
+85°C unless otherwise noted.
PARAMETER
MIN
TYP
MAX UNITS
CONDITIONS
Input Voltage
2.7
5.5
3
V
mA
µA
Quiescent Current
Shutdown Current
Maximum Load Current
Oscillator Frequency
VFB Reference Voltage
Output Resistance
0.9
1.0
VIN = 4.2V, VOUT = 3.6V, IOUT = 100µA
VEN/PWM = 0V, VIN = 5.5V
VIN = 4.2V, VOUT = 3.6V
VIN = 3.6V
1.5
280
1.2
mA
MHz
V
0.8
1.6
0.275
0.306
0.337
7.5
5
Ω
Ω
1.5X Mode, 100mA Load
1.0X Mode, 100mA Load
VMODE Threshold Voltage
VMODE Hysteresis
VMODE Pin Current
EN/PWM Logic Low
EN/PWM Logic High
EN/PWM Pin Current
FB Pin Current
1.15
1.6
1.25
30
1.35
V
mV
µA
V
VIN Falling @ 25°C
VIN = 3.6V @ 25°C
VMODE = 1.25 V
0.01
0.5
0.4
V
0.01
0.5
0.5
µA
µA
mV
VEN/PWM = 4.2V
VFB = 1V
VOUT Ripple
80
VIN = 5V, VOUT = 4V, IOUT = 100mA ,
1.5x Mode
VOUT Turn-On Time
175
500
µs
VIN = 3.6V, FB within 90% regulation
Date: 07/07/04
SP6683 White LEDs Driver for Parallel Configuration
© Copyright 2004 Sipex Corporation
2
PIN DESCRIPTION
PIN NUMBER
PIN NAME
VOUT
DESCRIPTION
1
2
3
4
Regulated charge pump output.
C1P
Positive terminal to the charge pump flying capacitor C2.
Input supply voltage.
VIN
VMODE
Charge pump mode program pin. When VMODE is greater than 1.25V,
a X1 charge pump is used. Otherwise, charge pump switches to X1.5
mode. A voltage divider shown in typical application circuit programs
the VIN threshold for charge pump mode switching.
5
6
FB
This is the feedback pin for output current or voltage regulation. The
voltage of this pin is compared with an internal 306mV reference.
EN/PWM
Enable and PWM dimming control input. Pull this pin low to discon-
nect VOUT from VIN and shutdown the SP6683.VOUT is pulled to
ground in shutdown.
7
8
C2N
GND
C1N
C2P
Negative terminal to the charge pump flying capacitor, C4.
Ground reference.
9
Negative terminal to the charge pump flying capacitor, C2.
Positive terminal to the charge pump flying capacitor C4.
10
FUNCTIONAL DIAGRAM
V
IN
C1P
1.2 MHz
Voltage
Reference
EN/PWM
Clock
Manager
Start-up
and
C1N
C2P
1.25V
Charge
Pump
Switches
MODE
COMP
Mode Control
V
C2N
MODE
V
OUT
306mV
V
OUT
COMP
FB
GND
Date: 07/07/04
SP6683 White LEDs Driver for Parallel Configuration
© Copyright 2004 Sipex Corporation
3
OPERATION
General Overview
4) VOUT Comparator and Output Control. A
306mV reference voltage is compared to feed-
back output voltage to control the Vout needed
for the application. Output current is set by a
bias resistor from FB pin to GND pin chosen by
the relationship:
The SP6683 is a current regulated charge pump
ideal for converting a Li-Ion battery input for
driving white LEDs used in backlighting color
displays in cellular phones, PDAs, digital cam-
eras and MP3 players. The SP6683 is able to
efficiently drive up to eight 20mA white LEDs
in parallel and maintain a constant brightness
over a very wide operating voltage range (2.7V
to 5.5V). The SP6683 operates with an internal
1.2MHz clock, enabling the use of small exter-
nal components. Other features of SP6683 in-
clude PWM dimming control as well as com-
plete input/out disconnect in shutdown. In shut
down mode the IC draws less than 1.5µA cur-
rent. The output regulation is achieved by sens-
ing the voltage at the feedback pin and modulat-
ing the switch between the charge pump and
output capacitor.
VFB
IOUT
=
RFB
where VFB = 306mV.
Configuring the SP6683 as Voltage or
Current Source
The white LED load configuration used by
customerscanbediscretewhiteLEDsorawhite
LED module. Inside the white LED module,
there may or may not be resistors in series with
the white LEDs. According to the different
application requirements, the SP6683 can be
configuredaseitheravoltagesourceoracurrent
source to provide solutions for these different
applications, as shown in figure 9~12. Figure 9
shows using the SP6683 to drive discrete white-
LEDs as a current source.
Theory of Operation
The SP6683 regulated charge pump block dia-
gram consists of four main blocks (Voltage
Reference,ModeControl,ClockManager,Start-
up and Charge-Pump Switches) and two com-
parators (VMODE Comparator and VOUT Com-
parator).
VOUT
1
SP6683
1) Voltage Reference. This block provides the
306mV and 1.25V reference voltages needed
for the two comparators.
5
FB
Rb
Rb
2) Mode Control. An external voltage divider
connected to the VMODE pin will define an input
voltage to the mode comparator which sets the
logic state of the mode selection outputs to the
X1 or X1.5 modes. VMODE is compared to a
1.25V bandgap voltage. For example, if one
makes a 158K/100K divider, the mode will
change at 2.58 x 1.25 V =3.23V. A comparator-
based cycle by cycle regulation ensures that no
mode change occurs during cycles.
GND
1uF
8
Figure 9. Driving discrete white LEDs as current source
The current in one white LED current is set by
the ratio of the feedback pin voltage (306mV)
and the bias resistor RB. To set the operating
current, RB can be selected by:
VFB
3) Clock Manager. An internal 1.2MHz clock
is generated in this block. Depending on the
mode control, the appropriate clock phasing is
generated here and sent to the start-up and
charge-pump switches block.
RB =
ILED
The current of the remaining white LEDs is set
according to the similarity of the white LEDs. 3-
wire white LED module with internal series
resistorsasshowninfigure10canalsobedriven
Date: 07/07/04
SP6683 White LEDs Driver for Parallel Configuration
© Copyright 2004 Sipex Corporation
4
OPERATION: Continued
in this way.
Anode
In this application, the bias resistor can be se-
lected by:
VFB
FB
RB =
ILED (TOTAL)
3-wire W-LED module
GND
where ILED(TOTAL) is the total operating current
of all the white LEDs.
Fig 10. 3-wire white LED module
In figure 11, SP6683 was used to drive a 2-wire
white LED module without internal series resis-
tors as a current source. The bias resistor RB is
selected to regulate the total current of the white
LED module instead of the current of single
LED as in figure 9.
To use SP6683 as a voltage source for fixed
voltage applications, a voltage divider is need to
program the ouput voltage, as shown in figure 12.
The output voltage is set by the ratio of the two
resistors and the feedback control voltage as
shown by:
Anode
VOUT
1
R
R6
V
OUT = ( 1 + 5 ) • VFB
SP6683
VOUT
Anode
1
5
2-wire W-LED module
5
R5
VFB
Cathode
SP6683
1uF
VFB
GND
Rb
R6
8
GND
8
2-wire W-LED
module
Cathode
Figure 11. Driving 2-wire white LED module as current
source
Figure 12. Driving 2-wire white LED module as
voltage source
Date: 07/07/04
SP6683 White LEDs Driver for Parallel Configuration
© Copyright 2004 Sipex Corporation
5
APPLICATION INFORMATION
PROGRAMMING THE OPERATING MODE
SP6683canautomaticallychangefromX1mode
to X1.5 mode for highest efficiency. To use this
feature, divider resistors should be chosen ac-
cording to the specific application, as shown in
figure 13.
Which can be expressed as R1:
R1 = VTH/1.25 - 1) • R2
3
VIN
For the typical SP6683 application, using VF =
3.6V, m = 8, ILED =15mA, ROUT = 6Ω, VTH will
be 4.63V, Select R2 = 100kΩ, then R1 = 270kΩ
VIN
R1
R2
SP6683
VMODE
4
Capacitor Selection
Ceramic capacitors are recommended for their
inherently low ESR, which will help produce
low peak to peak output ripple, and reduce high
frequency spikes.
C2
GND
8
The fly capacitor controls the strength of the
charge pump. Selection of the fly capacitor is a
trade-off between the output voltage ripple and
the output current capability. Decreasing the fly
capacitor will reduce the output voltage ripple
because less charge will be delivered to the
output capacitor. However, smaller fly capaci-
tor leads to larger output resistance, thus de-
creasing the output current capability and the
circuit efficiency. Place all the capacitors as
close to the SP6683 as possible for layout.
Increasing the value of the input and otput
capicitors could further reduce the input and
output ripple.
Figure 13. Programming the Vmode Resistors
Theguidelinefordividerresistorselectionsisas
follows. For high input voltage, the SP6683 will
work in X1 mode. When the input voltage drops
to Vth threshold voltage, it will switch to X1.5
mode automatically. The Vth threshold voltage
for mode change can be calculated by:
V
TH = (VF + 0.306 + m • ILED • ROUT)
Where VF and m are the forward voltage and
number of the white LEDs, Rout is the output
resistance of the SP6683.
Refer to table 1 for some suggested low ESR
capicitors.
The equation for the voltage divider R1 and R2
with VMODE = 1.25V is:
VTH = 1.25V • (1+R1/R2)
Table: 1
SUGGESTED LOW ESR CAPACITORS
MANUFACTURERS/
TELEPHONE#
PART NUMBER
CAPACITANCE/
VOLTAGE
CAPACITOR/ ESR
SIZE/TYPE
AT 100kHz
TDK/847-803-6100
C2012X5R1A225K
2.2µF/10V
0805/X5R
0.030Ω
0.020Ω
0.030Ω
0.020Ω
TDK/847-803-6100
C2012X5R0J475K
4.7µF/6.3V
2.2µF/6.3V
4.7µF/6.3V
0805/X5R
0603/X5R
0805/X5R
MURATA/770-436-1300
MURATA/770-436-1300
GRM188R60J225KE01D
GRM219R60J475KE01D
Date: 07/07/04
SP6683 White LEDs Driver for Parallel Configuration
© Copyright 2004 Sipex Corporation
6
APPLICATION INFORMATION: Continued
Since the brightness of the white LED is propor-
tional to the operating current, for better bright-
ness matching, a higher output voltage could be
used. This could be done by using larger resistor,
as shown in figure 14. Rb2 is used to bias the
operating current of the white LED, Rb1 is use to
increase the output voltage. Better brightness
matching was achived at the cost of the power
wasted on the bias resistor.
Brightness Control Using PWM
Dimming control can be achieved by applying
a PWM contol signal to the EN/PWM pin. The
brightness of the white LEDs is controlled by
increasing and decreasing the duty cycle of the
PWMsignal.Whileoperatingfrequencyrange
is from 60Hz to 700Hz, the recomended
maxium brightness frequncy range is from
60Hzto200Hz. Arepitionrateofatleast60Hz
is required to prevent flicker.
Power Efficiency
The efficiency of driving the white LEDs can be
calculated by
Brightness Matching
For white LEDs, the forward voltage drop is a
function of the operating current. However,
for a given current, the forward voltage drops
do not always match due to normal manufac-
turing tolerance, thus causing uneven bright-
ness of the white LEDs.
VF • IF
Vi • Ii
VF • IF
VF
η
=
=
≈
Vi • (n • IF + IQ)
Vi • n
Where Vi, Ii are input voltage and current VF, IF
are the forward voltage and operating current of
White LEDs IQ is quiescent current, which is
considered small compared with IF.
In figure 14, assume high-precision bias resis-
tors were used, the operating current ratio of
two different branches can be easily derived as
shown by:
I1
I2
V
OUT - VF1
=
VOUT - VF2
where I1 I2 are the operating current of the
white
LEDs,VF1,VF2 are the forward voltage of the
white LEDs.
VOUT
I1
I2
In
1
5
D1
VF1
D2
Dn
VF2
VFn
SP6683
Rb1
Rb
Rb
VFB
Rb2
GND
8
Rb
Figure 14. Increasing brightness matching
Date: 07/07/04
SP6683 White LEDs Driver for Parallel Configuration
© Copyright 2004 Sipex Corporation
7
PACKAGE: 10 PIN DFN
D
D/2
A3
E/2
E
Top View
A1
A
Side View
D2
2
1
10 Pin DFN
DIMENSIONS
(JEDEC MO-229,
in
(mm)
VEED-5 VARIATION)
E2
SYMBOL
MIN NOM MAX
0.80 0.90 1.00
A
A1
A3
b
D
D2
e
0.02 0.05
0.20 REF
0
K
L
0.18
0.25 0.30
3.00 BSC
2.20 2.70
0.50
-
e
b
PITCH
3.00 BSC
Bottom View
E
E2
K
1.40
0.20
-
-
1.75
-
L
0.30 0.40 0.50
10 Pin DFN
Date: 07/07/04
SP6683 White LEDs Driver for Parallel Configuration
© Copyright 2004 Sipex Corporation
8
PACKAGE: 10 PIN MSOP
D
e1
Ø1
E/2
R1
R
E1
E
Gauge Plane
L2
Ø
Ø1
0 0
Seating Plane
L
L1
1
2
e
Pin #1 indentifier must be indicated within this shaded area (D/2 * E1/2)
10-PIN MSOP
JEDEC MO-187
(BA) Variation
Dimensions in (mm)
MIN NOM MAX
B
B
A
-
-
1.10
0.15
0.00
-
A1
A2
b
0.75 0.85 0.95
0.17
0.08
-
0.27
0.23
(b)
c
-
WITH PLATING
D
E
3.00 BSC
4.90 BSC
E1
3.00 BSC
0.50 BSC
2.00 BSC
c
e
e1
L
0.4
0.60 0.80
BASE METAL
Section B-B
L1
L2
N
0.95 REF
0.25 BSC
10
R
0.07
0.07
0º
-
-
-
A2
R1
Ø
-
A
-
8º
15º
b
Ø1
5º
-
A1
10-PIN MSOP
Date: 07/07/04
SP6683 White LEDs Driver for Parallel Configuration
© Copyright 2004 Sipex Corporation
9
ORDERING INFORMATION
Operating Temperature Range Package Type
Part Number
SP6683ER .................................................. -40°C to +85°C ........................................................... 10 Pin DFN
SP6683ER/TR ............................................ -40°C to +85°C ........................................................... 10 Pin DFN
SP6683EU .................................................. -40°C to +85°C ........................................................ 10 Pin MSOP
SP6683EU/TR ............................................ -40°C to +85°C ........................................................ 10 Pin MSOP
Available in lead free packaging. To order add "-L" suffix to part number.
Example: SP6683ER/TR = standard; SP6683ER-L/TR = lead free
/TR = Tape and Reel
Pack quantity is 3000 for DFN.
Corporation
ANALOG EXCELLENCE
Sipex Corporation
Headquarters and
Sales Office
233 South Hillview Drive
Milpitas, CA 95035
TEL: (408) 934-7500
FAX: (408) 935-7600
Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the
application or use of any product or circuit described herein; neither does it convey any license under its patent rights nor the rights of others.
Date: 07/07/04
SP6683 White LEDs Driver for Parallel Configuration
© Copyright 2004 Sipex Corporation
10
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