Analog Devices ADP3000 a Datasheet

V

Micropower Step-Up/Step-Down Fixed 3.3 V, 5 V, 12 V,

Adjustable High Frequency Switching Regulator

FEATURES

Operates at supply voltages from 2 V to 30 V
Works in step-up or step-down mode
Very few external components required
High frequency operation up to 400 kHz
Low battery detector on-chip
User-adjustable current limit
Fixed and adjustable output voltage
8-lead PDIP, 8-lead SOIC, and 14-lead TSSOP packages
Small inductors and capacitors

APPLICATIONS

Notebook, palmtop computers
Cellular telephones
Hard disk drives
Portable instruments
Pagers

GENERAL DESCRIPTION

The ADP3000 is a versatile step-up/step-down switching
regulator. It operates from an input supply voltage of 2 V to
12 V in step-up mode, and from 2 V to 30 V in step-down mode.

Operating in pulse frequency mode (PFM), the device consumes
only 500 µA, making it ideal for applications requiring low
quiescent current. It delivers an output current of 180 mA at

3.3 V from a 2 V input in step-up mode, and an output current
of 100 mA at 3 V from a 5 V input in step-down mode.

The ADP3000 operates at 400 kHz switching frequency. This
allows the use of small external components (inductors and
capacitors), making it convenient for space-constrained designs.

The auxiliary gain amplifier can be used as a low battery detector,
linear regulator, undervoltage lockout, or error amplifier.

FUNCTIONAL BLOCK DIAGRAMS

IN

1.245V

REFERENCE

R1 R2

GND SENSE

V

IN

2V TO 3.2V

5V TO 6V

100µF

10V

V

IN

C1

100µF

120Ω

10V

C1, C2 = AVX TPS D107 M010R0100
L1 = SUMIDA CR43-100

Figure 3. Step-Down Mode Operation

SET

A1

GAIN BLOCK/
ERROR AMP

400kHz

OSCILLATOR

COMPARATOR

Figure 1.

6.8µH

120V

2

1

I

V

LIM

IN

SW1

ADP3000-3.3V

FB

(SENSE)

SW2GND

4

5

C1, C2 = AVX TPS D107 M010R0100
L1 = SUMIDA CR43-6R8

Figure 2. Typical Application

R

LIM

SW1

3

8

FB

1 2

I

LIMVIN

ADP3000

4

SW2

GND

5

D1

1N5818

3

8

ADP3000

DRIVER

ADP3000

IN5817

+

L1

10µH

C

L

+

100µF

10V

C1
100µF
10V

R2
150kΩ
1%

R1
110kΩ
1%

A0
I

LIM

SW1

SW2

3.3V
180mA

V

OUT

3V
100mA

00122-001

00122-002

00122-003

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.

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

ADP3000

TABLE OF CONTENTS

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

Programming the Gain Block................................................... 11

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

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

Pin Configurations and Function Descriptions ........................... 5

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

Theory of Operation ........................................................................ 9

Applications Information .............................................................. 10

Component Selection................................................................. 10

Programming the Switching Current Limit............................ 10

REVISION HISTORY

9/04—Data Sheet Changed from Rev. 0 to Rev. A

Added RU-14 Package .................................................Universal

Changes to Table 4.....................................................................10

Changes to Table 5.....................................................................10

Updated Outline Dimensions..................................................15

Changes to Ordering Guide.....................................................16

Power Transistor Protection Diode in Step-Down

Configuration ............................................................................. 11

Thermal Considerations............................................................ 11

Typical Application Circuits ......................................................... 13

Outline Dimensions....................................................................... 15

Ordering Guide .......................................................................... 16

1/97—Revision 0: Initial Version

Rev. A | Page 2 of 16

ADP3000

SPECIFICATIONS

0°C ≤ TA ≤ +70°C, VIN = 3 V, unless otherwise noted.1

Table 1.

ADP3000
Parameter Conditions Symbol Min Typ Max Unit

INPUT VOLTAGE Step-up mode V
Step-down mode 30.0 V
SHUT-DOWN QUIESCENT CURRENT VFB > 1.43 V; V
COMPARATOR TRIP POINT VOLTAGE ADP3000

2

OUTPUT SENSE VOLTAGE ADP3000-3.3

> 1.1 × V

SENSE

1.20 1.245 1.30 V

3

V

IQ 500 µA

OUT

ADP3000-53 4.75 5.00 5.25 V
ADP3000-123 11.40 12.00 12.60 V
COMPARATOR HYSTERESIS ADP3000 8 12.5 mV
OUTPUT HYSTERESIS ADP3000-3.3 32 50 mV
ADP3000-5 32 50 mV
ADP3000-12 75 120 mV
OSCILLATOR FREQUENCY f
DUTY CYCLE VFB < V
SWITCH-ON TIME I

LIM

D 65 80 %

REF

tied to VIN, VFB= 0 t

SWITCH SATURATION VOLTAGE TA = +25°C V

Step-Up Mode VIN = 3.0 V, ISW = 650 mA 0.5 0.75 V

V

= 5.0 V, ISW = 1 A 0.8 1.1 V

IN

Step-Down Mode VIN = 12 V, ISW = 650 mA 1.1 1.5 V
FEEDBACK PIN BIAS CURRENT ADP3000 VFB = 0 V I
SET PIN BIAS CURRENT V
GAIN BLOCK OUTPUT LOW I
REFERENCE LINE REGULATION

= V

SET

= 300 µA, V

SINK

5 V ≤ V

2 V ≤ V

I

REF

= 1.00 V V

SET

≤ 30 V

IN

≤ 5 V

IN

GAIN BLOCK GAIN RL = 100 kΩ4 A
GAIN BLOCK CURRENT SINK V
CURRENT LIMIT 220 Ω from I

≤ 1 V I

SET

to VIN I

LIM

CURRENT LIMIT TEMPERATURE COEFFICIENT

SWITCH-OFF LEAKAGE CURRENT Measured at SW1 pin 1 10 µA
V

= 12 V, TA = +25°C

SW1

MAXIMUM EXCURSION BELOW GND TA = +25°C

I

≤ 10 µA, switch off

SW1

2.0 12.6 V

IN

3.135 3.3 3.465 V

OUT

350 400 450 kHz

OSC

1.5 2 2.55 µs

ON

SAT

160 330 nA

FB

200 400 nA

SET

0.15 0.4 V

OL

0.02 0.15 %/V

0.2 0.6 %/V

1000 6000 V/V

V

300 µA

SINK

400 mA

LIM

−0.3

−400 −350

%/°C

mV

1

All limits at temperature extremes are guaranteed via correlation using standard statistical methods.

2

This specification guarantees that both the high and low trip points of the comparator fall within the 1.20 V to 1.30 V range.

3

The output voltage waveform will exhibit a saw-tooth shape due to the comparator hysteresis. The output voltage on the fixed output versions will always be within

the specified range.

4

100 kΩ resistor connected between a 5 V source and the AO pin.

Rev. A | Page 3 of 16

ADP3000

ABSOLUTE MAXIMUM RATINGS

Table 2.

Parameter Rating

Input Supply Voltage, Step-Up Mode 15 V
Input Supply Voltage, Step-Down Mode 36 V
SW1 Pin Voltage 50 V
SW2 Pin Voltage

Feedback Pin Voltage (ADP3000) 5.5 V
Switch Current 1.5 A
Maximum Power Dissipation 500 mW
Operating Temperature Range 0°C to +70°C
Storage Temperature Range

Lead Temperature (Soldering, 10 s) 300°C
Thermal Impedance

R-8 170°C/W
RU-14 150°C/W
N-8 120°C/W

ESD CAUTION

ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection. Although
this product features proprietary ESD protection circuitry, permanent damage may occur on devices
subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are
recommended to avoid performance degradation or loss of functionality.

−0.5 V to V

−65°C to +150°C

IN

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.

Rev. A | Page 4 of 16

ADP3000

V

V

PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS

1

I

LIM

V

2

IN

SW1 3
SW2 4

*FIXED VERSIONS

ADP3000

TOP VIEW

(Not to Scale)

FB (SENSE)*8
SET7

6

AO
GND5

Figure 4. 8-Lead Plastic DIP (N-8)

1

NC

2

NC

3

ILIM

VIN

SW1

NC

SW2

ADP3000

4

TOP VIEW

(Not to Scale)

5

6

7

00122-004

14

NC

13

FB

12

SET

11

AO
NC

10

9

NC

8

GND

I

1

LIM

V

2

IN

ADP3000

SW1

3

TOP VIEW

(Not to Scale)

SW2

4

*FIXED VERSIONS

Figure 6. 8-Lead SOIC (R-8)

FB (SENSE)*

8
7

SET

6

AO

5

GND

00122-005

NC = NO CONNECT

00122-035

Figure 5. 14-lead TSSOP (RU-14)

Table 3. Pin Function Descriptions

Mnemonic Function

I

For normal conditions, connect to VIN. When lower current is required, connect a resistor between I

LIM

and VIN.

LIM

To limit the switch current to 400 mA, connect a 220 Ω resistor.

VIN

Input Voltage.

SW1 Collector of Power Transistor. For step-down configuration, connect to VIN. For step-up configuration, connect

to an inductor/diode.

SW2 Emitter of Power Transistor. For step-down configuration, connect to inductor/diode. For step-up

configuration, connect to ground. Do not allow pin to go more than a diode drop below ground.
GND Ground.
AO

Auxiliary Gain Block (GB) Output. Open collector can sink 300 µA. This pin can be left open if not used.
SET Auxiliary Gain Amplifier Input. The amplifier’s positive input is connected to the SET pin, and its negative

input is connected to the 1.245 V reference. This pin can be left open if not used.
FB/SENSE On the ADP3000 (adjustable) version, this pin is connected to the comparator input. On the ADP3000-3.3,

the ADP3000-5, and the ADP3000-12, the pin goes directly to the internal resistor divider that sets the

output voltage.

IN

1.245V

REFERENCE

SET

A2

A1

COMPARATOR

GAIN BLOCK/
ERROR AMP

OSCILLATOR

DRIVER

A0
I

LIM

SW1

SW2

IN

1.245V

REFERENCE

SET

A1

COMPARATOR

GAIN BLOCK/
ERROR AMP

OSCILLATOR

DRIVER

A0
I

LIM

SW1

SW2

ADP3000

GND

FB

Figure 7. Functional Block Diagram for Adjustable Version

00122-006

R1 R2

GND SENSE

ADP3000

Figure 8. Functional Block Diagram for Fixed Version

00122-007

Rev. A | Page 5 of 16