SC560BULTRT_技术文档

SC560

Dual Output Low Noise LDO

Linear Regulator

POWER MANAGEMENT

Features

Description

Input voltage range — 2.5V to 5.5V

Output voltage ranges — 1.2V to 5.0V (each LDO)

Maximum output current — 300mA (both LDOs)

Dropout at 200mA load — 200mV max.

Quiescent supply current — 100μA (both LDOs

enabled)

Shutdown current — 100nA (typ)

Output noise < 50μV_RMS(SC560A and ﬁxed output

versions)

The SC560 is a family of dual output, ultra-low dropout

linear voltage regulators designed for use in battery

powered wireless applications. The SC560A, SC560B, and

SC560C provide adjustable output voltages that can be

set using two external resistors. Fixed output voltages

are also available (see ordering information for available

combinations). Fixed output devices provide the power-

good monitor, independent enable pins, and a bypass pin

for low-noise operation

PSRR < -65dB at 1kHz (SC560A and ﬁxed output

versions)

All members of the SC560 family require an input voltage

level between 2.5V and 5.5V. Output voltages for the

adjustable versions can vary between 1.2V and 5.0V. Fixed

output voltage options are also chosen from this range.

Over-temperature protection

Short-circuit protection

Under-voltage lockout

Power good monitor for output A (SC560C and ﬁxed

output versions)

Independent enable/disable for LDOB (SC560B and

ﬁxed output versions)

MLPQ-UT8, 1.5mm x 1.5mm x 0.6mm package

The SC560A provides superior low-noise performance

by using an external bypass capacitor connected to pin

7 to ﬁlter the bandgap reference. The SC560B uses pin 7

as a separate enable pin for the second regulator output

so the two outputs can be controlled independently.

The SC560C uses this pin to provide a PGOOD output

to hold a processor in reset when the voltage on OUTA

is not in regulation. All other versions provide all three

functions with ﬁxed output voltages (no feedback pins

are provided).

Applications

PDAs and cellular phones

GPS devices

Palmtop computers and handheld instruments

TFT/LCD applications

Wireless handsets

The device also provides protection circuitry such as

current limiting, under-voltage lockout, and thermal

protection to prevent device failures. Stability is

maintained by using 1ꢀF capacitors on the output pins.

The MLPQ-UT8 package and 0402 ceramic capacitors

minimize the required PCB area.

Digital cordless phones and PCS phones

Personal communicators

Wireless LAN

Typical Application Circuit

SC560D

PGOOD

OUTA

VIN

EN

VIN

EN

OUTA

OUTB

BYP

OUTB

ENB

C_IN

2.2μF

C_OUTB

1μF

C_BYP

22nF

C_OUTA

1μF

GND

March 28, 2008

1

SC560

Pin Conﬁguration

Ordering Information

Device

Package

SC560xULTRT^(1)(2)(3)

SC560xEVB⁽³⁾

MLPQ-UT8 1.5×1.5

Evaluation Board

8

1

2

3

7

6

5

Notes:

(1) Available in tape and reel only. A reel contains 3,000 devices.

(2) Available in lead-free package only. Device is WEEE and RoHS

compliant.

TOP VIEW

(3) The device variant is denoted by the x.

4

MLPQ-UT-8; 1.5x1.5, 8 LEAD

_JA= 157°C/W

θ

Marking Information

Pinout and Voltage Options

Output Voltage

Pin Options

Part

No.

Options

Device

Code

Pin 4

FBA

ENB

Pin7

BYP

Pin 8

FBB

V_LDOA

V_LDOB

ADJ

SC560A

SC560B

SC560C

SC560D

SC560E

SC560F

SC560G

SC560H

ADJ

0A

0B

0C

0D

0K

0L

ENB

FBB

ADJ

PGOOD

BYP

FBB

ADJ

PGOOD

2.8V

2.85V

2.5V

2.8V

3.3V

1.8V

2.85V

1.8V

1.5V

3.3V

0n

yw

BYP

0U

0S

BYP

0n = Part No. Code

See Pinout and Voltage Options Table for details

yw = Datecode

2

SC560

Absolute Maximum Ratings

Recommended Operating Conditions

VIN (V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to +6.5

EN, ENB (V) . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to (V_IN+ 0.3)

PGOOD (V) . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to (V_IN+ 0.3)

Pin Voltage — All Other Pins (V) . . . . . . . . . -0.3 to (V_IN+ 0.3)

OUTA, OUTB Short Circuit Duration . . . . . . . . Continuous

ESD Protection Level⁽¹⁾(kV) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Ambient Temperature Range (°C) . . . . . . . . . -40 < T_A< +85

V_IN(V) .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 < V_IN< 5.5

V_OUTA, V_OUTB(V).... . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 < V_OUT< 5.0

Thermal Information

Thermal Resistance, Junction to Ambient⁽²⁾(°C/W) . . . 157

Maximum Junction Temperature (°C) . . . . . . . . . . . . . . +150

Storage Temperature Range (°C). . . . . . . . . . . . -65 to +150

Peak IR Reflow Temperature (10s to 30s) (°C) . . . . . . . +260

Exceeding the above speciﬁcations may result in permanent damage to the device or device malfunction. Operation outside of the parameters

speciﬁed in the Electrical Characteristics section is not recommended.

NOTES:

(1) Tested according to JEDEC standard JESD22-A114-B.

(2) Calculated from package in still air, mounted to 3”x 4.5”, 4 layer FR4 PCB with thermal vias under the exposed pad per JESD51 standards.

Electrical Characteristics

Unless otherwise noted V_IN= 3.6V, C_IN= 2.2μF, C_OUTA= C_OUTB= 1μF, V_EN= V_ENB= V_IN, T_A= -40 to +85°C. Typical values are at T_A= 25°C. All

speciﬁcations apply to both LDOs unless otherwise noted.

Parameter

Symbol

V_IN

Conditions

Min

2.5

1.2

-3

Typ

Max

5.5

5.0

3

Units

V

Input Supply Voltage Range

Output Voltage

V_OUTx

ΔV_OUTx

I_MAX

V

Output Voltage Accuracy

Maximum Output Current

Dropout Voltage⁽¹⁾

V_IN= 2.5V to 5.5V, I_OUTx= 0 to 300mA

%

300

mA

mV

μA

V_D

I_OUTx= 200mA, V_OUTx= 2.5V to 5.0V

T_A= 25°C

100

0.1

200

1

Shutdown Current

I_SD

Quiescent Current

I_Q

I_OUTA= I_OUTB= 0mA, T_A= 25°C

100

Load Regulation

ΔV_LOAD

I_OUTx= 1mA to I_MAX

I_OUTx= 1mA

20

mV

Line Regulation

ΔV_LINE

V_FB

-6

6

mV

V

Feedback Regulation Voltage⁽²⁾

Current Limit

0.985

350

1

1.015

850

I_LIM

mA

3

SC560

Electrical Characteristics (continued)

Parameter

Symbol

Conditions

Min

Typ

Max

Units

V_IN= 3.7V, I_OUTx= 50mA ,

10Hz < f < 100kHz, C_BYP= 22nF

50

μV_RMS

Noise⁽³⁾

e_N

V_IN= 3.7V, I_OUTx= 50mA ,

10Hz < f < 100kHz

300

65

μV_RMS

dB

V_IN= 3.7V, I_OUTx= 50mA, f = 1kHz,

C

_BYP= 22nF

Power Supply Rejection

Ratio ⁽³⁾

PSRR

V_IN= 3.7V, I_OUTx= 50mA, f = 1kHz

40

PGOOD Delay⁽⁴⁾

t_DELAY

160

82

200

87

240

92

ms

%

Percentage of nominal output,

PGOOD Threshold⁽⁴⁾

V_TH-PGOOD

V

_OUTAfalling

From OFF to 87% V_OUTx, I_OUTx= 50mA,

Start-Up Time

t_SU

1

ms

μs

C

_BYP= 22nF⁽²⁾

Power Up Delay Between LDOA and

LDOB⁽⁵⁾

t_DELAY

Delay between V_OUTAand V_OUTBstart-ups

V_INRising

128

Under Voltage Lockout

UVLO Hysteresis

V_UVLO

2.15

2.25

100

2.35

V

V_UVLO-HYS

mV

Over Temperature Protection

Threshold

T_OT

Temperature Rising

160

20

°C

Over Temperature Hysteresis

Digital Inputs

T_OT-HYS

Logic Input High Threshold

Logic Input Low Threshold

Logic Input High Current

Logic Input Low Current

Digital Outputs

V_IH

V_IL

I_IH

V_IN= 5.5V

V_IN= 2.5V

V_IN= 5.5V

1.25

V

0.4

1

μA

I_IL

1

PGOOD Output voltage Low

Notes:

V_OL

I_SINK= 500μA,V_IN=3.7V

7

20

mV

(1) Dropout voltage is deﬁned as V_IN- V_OUTx, when V_OUTxis 100mV below the value of V_OUTxat V_IN= V_OUTx+ 0.5V.

(2) SC560A, SC560B and SC560C only

(3) Except SC560B and ﬁxed output versions

(4) Except SC560A and SC560B

(5) SC560A and SC560C only

4

SC560

Typical Characteristics

Load Regulation — LDOA

Load Regulation — LDOB

V_OUTA= 3.3V, V_IN= 3.6V

V_OUTB= 2.8V, V_IN= 3.6V

6

5

4

3

2

1

0

8

7

6

5

4

3

2

1

0

T_A=85

T_A=25

°

C

T_A=85°C

T_A=-40

°

C

°

T_A=25°C

T_A=-40°C

0

50

100

150

200

250

50

100

150

200

250

Output Current (mA)

Line Regulation — LDOA

Line Regulation — LDOB

V_OUTB= 2.8V, I_OUTB= 1mA

V_OUTA= 3.3V, I_OUTA= 1mA

3

2

1.5

1

2.5

2

1.5

1

0.5

T_A=85°C

T_A=85

°C

T_A=25°C

0.5

T_A=-40°C

0

T_A=25°C

0

T_A=-40°C

-0.5

2.9 3.1

3.3

3.5

3.7

3.9

4.1

4.3

4.5

4.7

4.9

5.1

5.3

5.5

3.3

3.5

3.7

3.9

4.1

4.3

4.5

4.7

4.9

5.1

5.3

5.5

Input Voltage (V)

Dropout Voltage LDOA

Dropout Voltage LDOB

V_OUTA= 3.3V, I_OUTA= 200mA

V_OUTB= 2.8V, I_OUTB= 200mA

400

300

250

200

150

100

350

300

250

200

150

100

50

T_A=85°C

T_A=25°C

T_A=-40

2.85

°C

T_A=25°C

50

0

T_A=-40°C

0

2.95

3

3.05 3.1 3.15 3.2 3.25 3.3 3.35 3.4 3.45 3.5 3.55 3.6

2.5

2.55

2.6

2.65

2.7

2.75 2.8

2.9

2.95

3

3.05

3.1

Input Voltage (V)

5

SC560

Typical Characteristics (continued)

PSRR vs. Frequency (Both LDOs)

V_OUT= 2.8V, I_o=50mA, C_BYP=22nF

0

V_OUT= 2.8V, I_O= 50mA

0

-10

-20

-30

-40

-50

-60

-70

-80

-90

-10

-20

-30

-40

-50

-60

-70

10

100

1000

10000

10

100

1000

10000

Frequency (Hz)

Output Noise vs. Load Current (Both LDOs)

V_OUT= 2.8V, V_IN=3.7V, C_BYP=22nF

V_OUT= 2.8V, V_IN= 3.7V, no C_BYP

80

70

60

50

40

30

20

10

0

450

400

350

300

250

200

150

100

50

T_A=85

T_A=25

°

C

T=85

°

C

°

T=25

°

C

T_A=-40°C

T=-40°C

0

50

100

150

200

250

0

50

100

150

200

250

Output Current (mA)

Load Transient Response

Rising Edge (Both LDOs)

Load Transient Response

Falling Edge (Both LDOs)

V_IN= 3.6V, V_OUT= 2.8V

I_OUT=10mA to

200ma

(100mA/div)

(100mA/div))

V_OUT

(10mV/div)

6

SC560

Pin Conﬁgurations and Descriptions

Pin #

Name

Pin Function

SC560

Fixed Output

SC560A

SC560B

SC560C

1

2

3

1

2

3

1

2

3

1

OUTB

VIN

Output for LDOB

2

3

Input supply voltage terminal

Output for LDOA

OUTA

Feedback sense pin for LDOA — Connect this pin to an

external resistor divider to set V_OUTA

4

5

6

4

5

6

FBA

5

6

7

5

6

7

4

GND

EN

Analog and digital ground

Logic input — active HIGH enables both LDOs for the SC560A and

SC560C, or LDOA for all other variants.

BYP

ENB

LDO bypass output — Bypass with a 22nF capacitor

7

8

Logic input — active HIGH enables LDOB for SC560B and SC560D

Power Good output — monitors the level of LDOA, switches low

when the output drops out of regulation.

7

8

PGOOD

FBB

Feedback sense pin for LDOB — Connect this pin to an external

resistor divider to set V_OUTB

8

7

SC560

Block Diagrams

SC560A

VIN

2

5

6

VREF

7

BYP

UVLO

O/T

VIN

3

4

OUTA

FBA

GND

EN

LDOA

LDOB

Power-

ON

Logic

1

8

OUTB

FBB

SC560B

VIN

2

5

VREF

UVLO

O/T

VIN

3

4

OUTA

FBA

GND

LDOA

LDOB

6

7

EN

Power-

ON

Logic

1

8

OUTB

FBB

ENB

8

SC560

Block Diagrams (continued)

SC560C

VIN

2

5

6

7

VREF

PGOOD

Logic

UVLO

VIN

3

4

OUTA

FBA

GND

EN

O/T

LDOA

LDOB

Power-

ON

Logic

1

8

OUTB

FBB

SC560 – Fixed Output Versions

VIN

2

VREF

7

8

VIN

BYP

PGOOD

Logic

UVLO

VIN

5

6

4

GND

OUTA

OUTB

O/T

LDOA

LDOB

3

1

EN

VIN

Power-

ON

Logic

ENB

9

SC560

Applications Information

The SC560B and the ﬁxed output variants provide

a separate enable pin for LDOB which allows LDOA

and LDOB to be enabled independently. The EN pin

controls the LDOA output and the ENB provides the

same functionality relative to the LDOB output. The

table shown below lists the eﬀect of the polarity of the

EN and ENB signals on the outputs of LDOA and LDOB.

Since LDOB can be enabled separately, there is no timing

relationship between the two outputs at startup.

General Description

TheSC560isafamilyofdualoutputlinearregulatordevices

intended for applications where low dropout voltage, low

supply current, and low output noise are critical. Each

device provides a very simple, low cost solution for two

separate regulated outputs. Very little PCB area is required

due to the miniature package size and the need for only

four external capacitors.

The linear regulators LDOA and LDOB are powered from

a single input supply rail, and each provides 300mA of

output current. The SC560 can provide output voltages

in the range 1.2V to 5.0V. The output voltages for the

SC560A, SC560B and SC560C are set by connecting

external resistor dividers to the feedback pins of each

LDO. All other versions of the SC560 have ﬁxed output

voltage values shown in the Pinout and Voltage Options

table.

EN

ENB

LDOA

LDOB

Low

High

Low

High

Low

High

Oﬀ

On

Oﬀ

On

Power On Control

The SC560A and SC560C devices have a single enable pin

(EN) that controls both LDO outputs. Pulling this pin low

causes the device to enter a low power shutdown mode

where it typically draws 100nA from the input supply.

The SC560C and the ﬁxed output variants have a PGOOD

signal which monitors the output of LDOA and transitions

high 200ms after LDOA has reached 87% of its regulation

point. This can be used to hold a processor in reset when

the output voltage is out of regulation.

When EN transitions high, the output of LDOA is enabled.

After a delay of 128μs, the output of LDOB is enabled. In

the SC560C, when the output voltage of LDOA reaches

87% of its regulation point, the delay timer starts and the

PGOOD signal transitions high after a delay of 200ms. The

power up/down sequence is shown in the timing diagram

in Figure 1.

Output Voltage Selection

The output voltage of each LDO for the SC560A, SC560B,

and SC560C version is set independently using external

resistordividers.Figure2illustratestheproperconnection

for LDOA.

OUTA

FBA

EN

87%

R₁

R₂

OUTA

PGOOD

OUTB

200ms

128μs

Figure 1 — Timing Diagram

Figure 2 — Output Voltage Feedback Circuit

10

SC560

Applications Information (continued)

The values of the resistors in the voltage divider network

can be calculated using the equation:

Short-Circuit Protection

Each output has short-circuit protection. If the output

current exceeds the current limit, the output voltage will

drop and the output current will be limited until the load

current returns to a speciﬁed level. If a short-circuit occurs

on the output of LDOA, the output of LDOB will also be

disabled until the fault is removed and the load current

returns to a speciﬁed level.

ꢀ

R₁ꢂ R₂

R₂

ꢁ

V_OUT V_REF

where V_REF= 1V. The value of R2 should be 100kΩ or

less to ensure noise performance and stability. Values

signiﬁcantly less than 100kΩ will impact the quiescent

current.

Component Selection

A capacitance of 1μF or larger on each output is

recommended to ensure stability. Ceramic capacitors

of type X5R or X7R should be used because of their

low ESR and stable temperature coeﬃcients. It is also

recommended that the input be bypassed with a 2.2μF,

low ESR X5R or X7R capacitor to minimize noise and

improve transient response. Note: Tantalum and Y5V

capacitors are not recommended.

Protection Features

The SC560 family provides the following protection

features to ensure that no damage is incurred in the

^ev•^ent^U^oⁿ^f^d^a^e^f^r^a^-^u^V^l^o^t^l^c^ta^o^gⁿ^e^di^L^t^o^io^cⁿ^k^:^out

• ^{Over-Temperature Protection}

• ^{Short-Circuit Protection}

Under-Voltage Lockout

The BYP pin on the SC560D and the ﬁxed output versions

must have a minimum of 22nF connected to ground to

meet all noise-sensitive requirements. Increasing the

capacitance to 100nF will further improve PSRR and

output noise.

The Under-Voltage Lockout (UVLO) circuit protects the

device from operating in an unknown state if the input

voltage supply is too low.

When the V_INdrops below the UVLO threshold, the LDOs

are disabled and PGOOD is held low (SC560C and ﬁxed

output variants only). When V_INis increased above the

hysteresis level, the LDOs are re-enabled into their

previous states, provided EN has remained high. When

powering up with V_INbelow the UVLO threshold, the

LDOs remain disabled and PGOOD is held low (SC560C

and ﬁxed output variants only).

Over-Temperature Protection

An internal Over-Temperature (OT) protection circuit is

providedthatmonitorstheinternaljunctiontemperature.

When the temperature exceeds the OT threshold as

deﬁned in the Electrical Characteristics section, the OT

protection disables both LDO outputs and holds the

PGOOD signal low. When the junction temperature drops

below the hysteresis level, the LDOs are re-enabled into

their previous states and PGOOD transitions high after a

200ms delay, provided EN has remained high (SC560C

and ﬁxed output variants only).

11

SC560

Applications Information (continued)

The following procedure can be followed to determine if

the thermal design of the system is adequate.The junction

temperature of the SC560 can be determined in known

operating conditions using the following equation:

Thermal Considerations

Although each of the two LDOs in the SC560 can provide

300mA of output current, the maximum power dissipation

in the device is restricted by the miniature package size.

The graphs in Figure 3 and Figure 4 can be used as a

guideline to determine whether the input voltage, output

voltages, output currents, and ambient temperature of the

system result in power dissipation within the operating

limits are met or if further thermal relief is required.

0.7

T_J= T_A+(P_Dx θ_JA)

where

T_J= Junction Temperature (°C)

T_A= Ambient Temperature (°C)

P_D= Power Dissipation (W)

θ_JA= Thermal Resistance Junction to Ambient (°C/W)

0.6

0.5

Example

0.4

Vo=3.3V

An SC560D is used to provide outputs of 2.8V, 150mA from

LDOA and 1.8V, 200mA from LDOB. The input voltage is

4.2V, and the ambient temperature of the system is 40°C.

Vo=1.5V

0.3

0.2

P_D= 0.15(4.2 – 2.8) + 0.2(4.2 – 1.8)

= 0.69W

0.1

______

T_A=+25°C, P_D(MAX)= 0.8W

- - - - T_A=+85

°

C, P_D(MAX)= 0.41W

0

4.5

Input Voltage (V)

5.5

6

2.5

3

3.5

4

5

and

Figure 3 — Safe Operating Limit

T_J= 40 + (0.69 x 157) = 148.3°C

1.6

1.4

1.2

1

Figures 3 and 4 show that the junction temperature

would be within the maximum speciﬁcation of 150°C

for this power dissipation. This means that operation of

the SC560 under these conditions is within the speciﬁed

limits and the device would not require further thermal

relief measures.

T_J(Max)=150°C

0.8

0.6

0.4

T_J(Max)=125°C

0.2

0

60

80

100

-40

-20

0

20

40

Ambient Temperature (^oC)

Figure 4 — Maximum P_Dvs. T_A

12

SC560

Applications Information (continued)

• Connect all ground connections directly to the

Layout Considerations

ground plane whenever possible to minimize

ground potential diﬀerences on the PCB.

While layout for linear devices is generally not as critical as

for a switching application, careful attention to detail will

ensure reliable operation. The diagram below illustrates

proper layout of a circuit using the SC560A.

• ^{Ensure that the feedback resistors are placed as}

close as possible to the feedback pins.

• ^{Attach the part to a large copper footprint, to}

enable better heat transfer from the device

on PCBs where there are internal power and

ground planes.

• ^{Place the input, output, and bypass capacitors}

close to the device for optimal transient

response and device behavior.

R4

C3

R3

1

C1

U1

C4

C2

R1

R2

U1 = SC560A

13

SC560

Outline Drawing — MLPQ-UT8

A

D

B

E

DIMENSIONS

INCHES MILLIMETERS

DIM

A

A1 .000

A2

b

D

E

e

MIN NOM MAX MIN NOM MAX

-

.018

.024 0.45

.002 0.00

0.60

0.05

(.006)

(0.1524)

PIN 1

INDICATOR

(LASER MARK)

.006 .008 .010 0.15 0.20 0.25

.059 BSC

.016 BSC

1.50 BSC

0.40 BSC

L

N

0.12 .014 0.16 0.30 0.35 0.40

8

aaa

bbb

.004

0.10

A2

C

A

SEATING

PLANE

aaa

C

A1

LxN

e

2

1

0.20

0.17

0.25

N

bxN

bbb

C A

B

NOTES:

CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES).

COPLANARITY APPLIES TO THE EXPOSED PAD AS WELL AS THE TERMINALS.

1.

2.

14

SC560

Land Pattern — MLPQ-UT8

Z

DIMENSIONS

INCHES

G

DIM

MILLIMETERS

(.057)

.028

.016

.004

.008

.030

.087

(1.45)

0.70

0.40

0.10

0.20

0.75

2.20

C

G

P

R

X

Y

Z

P

(Z)

(G)

2X (C)

X

R

Y

NOTES:

1.

2.

CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES).

THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY.

CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR

COMPANY'S MANUFACTURING GUIDELINES ARE MET.

Contact Information

Semtech Corporation

Power Management Products Division

200 Flynn Road, Camarillo, CA 93012

Phone: (805) 498-2111 Fax: (805) 498-3804

www.semtech.com

15


型号：	SC560BULTRT
厂家：	SEMTECH CORPORATION
描述：	暂无描述稳压器
文件：	总15页 (文件大小：287K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

SC560BULTRT [SEMTECH]

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