ANALOG DEVICES ADP1610 Service Manual

1.2 MHz DC-to-DC Step-Up Switching

S

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FEATURES

Fully integrated 1.2 A, 0.2 Ω, power switch
Pin-selectable 700 kHz or 1.2 MHz PWM frequency
92% efficiency
Adjustable output voltage up to 12 V
3% output regulation accuracy
Adjustable soft start
Input undervoltage lockout
MSOP 8-lead package

APPLICATIONS

TFT LC bias supplies
Portable applications
Industrial/instrumentation equipment

FUNCTIONAL BLOCK DIAGRAM

REF

FB

2

RAMP

GEN

7

RT

OSC

ERROR

g

m

COMP

1 6

AMP

COMPARATOR

Converter

ADP1610

GENERAL DESCRIPTION

The ADP1610 is a dc-to-dc step-up switching converter with
an integrated 1.2 A, 0.2  power switch capable of providing
an output voltage as high as 12 V. With a package height of less
than 1.1 mm, the ADP1610 is optimal for space-constrained
applications such as portable devices or thin film transistor
(TFT) liquid crystal displays (LCDs).

The ADP1610 operates in pulse-width modulation (PWM) current
mode with up to 92% efficiency. Adjustable soft start prevents
inrush currents at startup. The pin-selectable switching frequency
and PWM current mode architecture allow excellent transient
response, easy noise filtering, and the use of small, cost-saving
external inductors and capacitors.

The ADP1610 is offered in the RoHS compliant 8-lead MSOP
and operates over the temperature range of −40°C to +85°C.

IN

ADP1610

BIAS

SW

F/F

QSR

DRIVER

5

8

SOFT START

SS

3

D

Rev. A

Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.

CURRENT

SENSE

AMPLIFIER

4

Figure 1.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] www.analog.com
Fax: [phone] ©2004–2008 Analog Devices, Inc. All rights reserved.

GND

04472-001

ADP1610

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TABLE OF CONTENTS

Features .............................................................................................. 1

Applications ....................................................................................... 1

General Description ......................................................................... 1

Functional Block Diagram .............................................................. 1

Revision History ............................................................................... 2

Specifications ..................................................................................... 3

Absolute Maximum Ratings ............................................................ 4

ESD Caution .................................................................................. 4

Pin Configuration and Function Descriptions ............................. 5

Typical Performance Characteristics ............................................. 6

Theory of Operation ...................................................................... 10

Current Mode PWM Operation ............................................... 10

Frequency Selection ................................................................... 10

Soft Start ...................................................................................... 10

On/Off Control ........................................................................... 10

Setting the Output Voltage ........................................................ 10

Inductor Selection ...................................................................... 10

Choosing the Input and Output Capacitors ........................... 11

Diode Selection ........................................................................... 13

Loop Compensation .................................................................. 13

Soft Start Capacitor .................................................................... 14

Application Circuits ................................................................... 15

DC-to-DC Step-Up Switching Converter with True

Shutdown ..................................................................................... 15

TFT LCD Bias Supply ................................................................ 15

Sepic Power Supply .................................................................... 16

Layout Procedure ........................................................................... 17

Outline Dimensions ....................................................................... 18

Ordering Guide .......................................................................... 18

REVISION HISTORY

9/08—Rev. 0 to Rev. A

Changes to Table 4 .......................................................................... 11

Changes to Table 5 .......................................................................... 14

10/04—Revision 0: Initial Version

Rev. A | Page 2 of 20

ADP1610

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SPECIFICATIONS

VIN = 3.3 V, TA = −40°C to +85°C, unless otherwise noted. All limits at temperature extremes are guaranteed by correlation and
characterization using standard statistical quality control (SQC), unless otherwise noted.

Table 1.

Parameter Symbol Conditions Min Typ Max Unit
SUPPLY

Input Voltage VIN 2.5 5.5 V
Quiescent Current

Nonswitching State IQ V
Shutdown I

Switching State

1

V

SD

Q

I

F

QSW

OUTPUT

Output Voltage V

V

OUT

Load Regulation I
Overall Regulation Line, load, temperature ±3 %

REFERENCE

Feedback Voltage VFB 1.212 1.230 1.248 V
Line Regulation VIN = 2.5 V to 5.5 V −0.15 +0.15 %/V

ERROR AMPLIFIER

Transconductance gm ∆I = 1 A 100 µA/V
Voltage Gain AV 60 dB
FB Input Bias Current VFB= 1.23 V 10 nA

SWITCH

SW On Resistance RON I
SW Leakage Current VSW = 12 V 0.01 20 µA
Peak Current Limit

2

I

2.0 A

CLSET

OSCILLATOR

Oscillator Frequency f

RT = GND 0.49 0.7 0.885 MHz

OSC

RT = IN 0.89 1.23 1.6 MHz
Maximum Duty Cycle D

COMP = open, VFB = 1 V, RT = GND 78 83 90 %

MAX

SHUTDOWN

Shutdown Input Voltage Low VIL Nonswitching state 0.6 V
Shutdown Input Voltage High VIH Switching state 2.2 V
Shutdown Input Bias Current I

SD

SOFT START

SS Charging Current VSS = 0 V 3 µA

UNDERVOLTAGE LOCKOUT

3

UVLO Threshold VIN rising 2.2 2.4 2.5 V
UVLO Hysteresis 220 mV

1

This parameter specifies the average current while switching internally and with SW (Pin 5) floating.

2

Guaranteed by design and not fully production tested.

3

Guaranteed by characterization.

= 1.3 V, RT = VIN 390 600 A

FB

= 0 V 0.01 10 µA

SD

= 1.23 MHz, no load 1 2 mA

SW

12 V

IN

= 10 mA to 150 mA, V

LOAD

= 1.0 A 200 400 mΩ

SW

= 10 V 0.05 mV/mA

OUT

VSD = 3.3 V 0.01 1 µA

Rev. A | Page 3 of 20

ADP1610

7

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ABSOLUTE MAXIMUM RATINGS

Table 2.

Parameter Rating
IN, COMP, SD, SS, RT, FB to GND

−0.3 V to +6 V
SW to GND 14 V
RMS SW Pin Current 1.2 A
Operating Ambient Temperature Range −40°C to +85°C
Operating Junction Temperature Range −40°C to +125°C
Storage Temperature Range −65°C to +150°C
θJA, Two Layers 206°C/W
θJA, Four Layers 142°C/W
Lead Temperature (Soldering, 60 sec) 300°C

Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.

R

C

C

C

V

R1

1.2MHz

00kHz

C

SS

OUT

FB

R2

V

IN

SD

SS

REF

2

RAMP

GEN

RT

7

OSC

3

SOFT START

8

COMP

1 6

ERROR

AMP

g

m

COMPARATOR

Figure 2. Block Diagram and Typical Application Circuit

ESD CAUTION

IN

IN

ADP1610

BIAS

F/F

QSR

DRIVER

CURRENT

SENSE

AMPLIFIER

C

IN

L1

D1

SW

5

4

GND

V

OUT

C

OUT

04472-002

Rev. A | Page 4 of 20

ADP1610

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PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

1

COMP

GND

ADP1610

FB

2

TOP VIEW

SD

3

(Not to Scale)

4

Figure 3. Pin Configuration

8

SS

RT

7

IN

6

SW

5

04472-003

Table 3. Pin Function Descriptions

Pin No. Mnemonic Description

1 COMP

Compensation Input. Connect a series resistor-capacitor network from COMP to GND to compensate the
regulator.

2 FB

Output Voltage Feedback Input. Connect a resistive voltage divider from the output voltage to FB to set the
regulator output voltage.

3

Shutdown Input. Drive SD low to shut down the regulator; drive SD high to turn it on.

SD
4 GND Ground.
5 SW

Switching Output. Connect the power inductor from the input voltage to SW and connect the external rectifier
from SW to the output voltage to complete the step-up converter.

6 IN

Main Power Supply Input. IN powers the ADP1610 internal circuitry. Connect IN to the input source voltage.
Bypass IN to GND with a 10 µF or greater capacitor as close to the ADP1610 as possible.

7 RT

Frequency Setting Input. RT controls the switching frequency. Connect RT to GND to program the oscillator to 700 kHz,
or connect RT to IN to program the oscillator to 1.2 MHz.

8 SS Soft Start Timing Capacitor Input. A capacitor from SS to GND brings up the output slowly at power-up.

Rev. A | Page 5 of 20

ADP1610

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TYPICAL PERFORMANCE CHARACTERISTICS

100

V

= 10V

OUT

F

= 700kHz

SW

90

L = 10µH

80

70

60

50

40

EFFICIENCY (%)

30

20

10

0

110100

LOAD CURRENT (mA)

Figure 4. Output Efficiency vs. Load Current

VIN = 5.5V

VIN = 3.3V

VIN = 2.5V

04472-005

1k

100

V

= 7.5V

OUT

F

= 1.2MHz

SW

L = 4.7µH

90

80

70

60

EFFICIENCY (%)

50

40

30

110100

LOAD CURRENT (mA)

Figure 7. Output Efficiency vs. Load Current

VIN = 5.5V

VIN = 3.3V

VIN = 2.5V

04472-008

1k

100

V

= 10V

OUT

F

= 1.2MHz

90

SW

L = 4.7µH

80

70

60

50

40

EFFICIENCY (%)

30

20

10

0

1 10 100 1K

LOAD CURRENT (mA)

Figure 5. Output Efficiency vs. Load Current

100

V

= 7.5V

OUT

F

= 700kHz

SW

90

L = 10µH

80

70

60

EFFICIENCY (%)

50

40

30

110100

LOAD CURRENT (mA)

Figure 6. Output Efficiency vs. Load Current

VIN = 5.5V

VIN = 3.3V

VIN = 2.5V

VIN = 5.5V

VIN = 3.3V

VIN = 2.5V

04472-006

04472-007

1k

2.4

2.2

2.0

1.8

1.6

CURRENT LIMIT (A)

1.4

1.2
–40 –15 10 35 60 85

AMBIENT TEMPERATURE (°C)

Figure 8. Current Limit vs. Ambient Temperature, V

1.4

1.2

1.0

0.8

0.6

0.4

OSCILLATORY FREQUENCY (MHz)

V

0.2

0

–40 –15 10 35 60 85

= 10V

OUT

V

= 3.3V

IN

AMBIENT TEMPERATURE (°C)

Figure 9. Oscillatory Frequency vs. Ambient Temperature

V

= 5.5V

IN

V

= 3.3V

IN

VIN = 2.5V

= 10 V

OUT

RT = V

RT = GND

04472-009

IN

04472-010

Rev. A | Page 6 of 20