PRELIMINARY TECHNICAL DATA
a
Preliminary Technical Data
FEATURES
1 MHz PWM Frequency
Ultrasmall 8-lead 3×3 Sq. mm Chip Scale Package
Automatic PWM to Power Saving Mode at Light Load
Fully Integrated 1.5 A Power Switch
3% Output Regulation Accuracy over Temperature,
Line, and Load
100% Duty Cycle Operation
Simple Compensation
Output Voltage: 1.25 V to 10 V
Small Inductor and MLC Capacitors
Low Quiescent Current while Pulse Skipping
Thermal Shutdown
Fully Integrated Soft Start
Cycle-by-cycle Current Limit
APPLICATONS
PDAs and Palmtop Computers
Notebook Computers
PCMCIA Cards
Bus Products
Portable Instruments
Industrial Systems
GENERAL DESCRIPTION
IN
IN
1 MHz, 1 A Buck Regulator
ADP3089
FUNCTIONAL BLOCK DIAGRAM
SW
CURRENT
SENSE
PWM
1MHz
AMP
COMPARATOR
S Q
R
DRV
PROTECTION
LOGIC
(ILIM, OT)
ERROR
AMP
gm
RUN/STOP
COMPARATORS
FB
SOFT-START
TIMER
COMP
GND
GND
+ REF
1.245V
VIN
10µF
ADP3089
SW
IN
0.1µF
IN
GND
COMP
DRV
GND
FB
10µH
20BQ030
18.2kΩ
22µF
41.2kΩ
VOUT
1.8V@1A
The ADP3089 is a high frequency, non-synchronous PWM
step-down DC-DC regulator with an integrated 1.5 A
power switch in a space-saving chip scale package. It pro-
vides high efficiency, excellent dynamic response, and is
very simple to use.
The ADP3089’s 1 MHz switching frequency allows for
small, inexpensive external components, and the current
mode control loop is simple to compensate and eases noise
filtering. It operates in PWM current mode under heavy
loads and saves energy at lighter loads by switching auto-
matically into Power Saving mode. Soft start is integrated
completely on chip, as is the cycle-by-cycle current limit.
Capable of operating from 2.5 V to 11 V input with a
typical output current of 1 A, it is ideal for portable, bat-
tery powered, industrial, PC and instrumentation applica-
tions. Supporting output voltages down to 1.25 V, the
ADP3089 is ideal to generate low voltage rails, providing
the optimal solution in its class for delivering power effi-
ciently, responsively, and simply with minimal printed
circuit board area.
The device is specified over the industrial temperature
range of -40°C to +85°C, and is offered in an ultrasmall 8-
lead 3×3 square mm chip scale package.
REV. PrE
8/26/02
47pF
470pF
10.7kΩ
Figure 1. Typical Application
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
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P Box 9106, Norwood, MA 02062-9106, U.S.A.
.O.
Tel: 781/329-4700
World Wide Web Site: http://www.analog.com
Fax: 781/326-8703
Analog Devices, Inc., 2002
PRELIMINARY TECHNICAL DATA
ADP3089–SPECIFICATIONS
1
(V = +3.3 V, T = -40°C to +85°C, unless otherwise noted)
IN
A
Parameter
SUPPLY
Input Voltage Range
Quiescent Current
Operating
Symbol
V
IN
I
Q
I
SD
I
GND2
T
SD
f
SW
D
PSM
D
MAX
V
HYST
V
IO3
I
LIM
Conditions
DRV to GND
V
IN
= 10 V, I
L
= 1 A,
DRV = GND
No load
V
COMP
= 0 V
V
IN
= 10 V, I
L
= 1 A,
DRV = 2 V
Min
2.5
Typ
Max
11
Units
V
mA
12
180
15
3
160
0.75
100
20
1
14
30
.7
1.5
1.7
0.5
1.25
280
40
3.6
Shutdown
Ground Current
Normal Operation
Thermal Shutdown Threshold
OSCILLATOR
Oscillator Frequency
Minimum Sleep Duty Cycle
Maximum Duty Cycle
Wake up Hysteresis
OUTPUT SWITCH
Switch On Voltage
Current Limit Threshold
Leakage Current
ERROR AMPLIFIER
Reference Voltage Accuracy
Reference Voltage Line
Regulation
Feedback Input Bias Current
Maximum Output Current
Short Circuit Current
Transconductance
MODULATOR
Transconductance
Control Offset Voltage
Soft Start Time
Shutdown Threshold Voltage
Slope Compensation
µA
µA
mA
°C
MHz
%
%
mV
V
A
µA
V
%/V
nA
µA
µA
µA/V
A/V
V
µs
mV
A/µs
FB voltage drops below V
REF
I
L
= 1A,
FB and DRV tied to
GND
40
1.0
2
V
IN
= 12 V
V
REF
I
FB
I
COMP
,
I
COMP
,
g
m
,
EA
FB tied to COMP
FB tied to COMP,
V
IN
= 3 V to 12 V
soft start expired
SC
SD
1.222
1.245 1.265
.02
1
60
20
480
1
0.90
250
50
85
40
-50
35
V
COMP
= 0 V, activating
shutdown
V
FB
to I
COMP
V
COMP
to I
L
340
Effectively summed to I
SW
g
m
,
MOD
V
PWM
,
OS
t
SS
V
COMP
,
SD
m
SC
600
750
0.5
NOTES
1 All limits at temperature extremes are guaranteed via correlation using standard Statistical Quality Control (SQC).
2 For higher efficiency operation, tie the DRV pin to the output for I
L
< 250 mA, and V
IN
> 3 V.
3 V(IN) - V(SW), includes voltage drop across internal current sensor.
Specifications subject to change without notice.
–2–
REV. PrE
PRELIMINARY TECHNICAL DATA
ADP3089
ABSOLUTE MAXIMUM RATINGS*
PIN FUNCTION DESCRIPTIONS
Input Supply Voltage .............................. –0.3 V to +12 V
Voltage on any pin with respect to GND
............................................................ –0.3 V to +12 V
(voltage on any pin may not exceed V
IN
)
Operating Ambient Temperature Range .. –40°C to +85°C
Operating Junction Temperature ......................... +125°C
θ
JA
(4-layer board) ............................................... 47°C/W
Storage Temperature Range .................. –65°C to +150°C
Lead Temperature Range (Soldering, 10 sec) ..... +240°C
Vapor Phase (60 sec) ........................................ +240°C
Infrared (20 sec) ............................................... +240°C
*This is a stress rating only; operation beyond these limits can cause the device
to be permanently damaged. Unless otherwise specified, all voltages are
referenced to GND.
Pin
1, 2
3, 6
4
Mnemonic
IN
GND
COMP
Function
Power Supply Input. Both pins
must be connected.
Ground. Both pins must be con-
nected.
Feedback Loop Compensation
and Shutdown Input. An open
drain or collector used to pull
the pin to ground will shutdown
the device.
Feedback Voltage Sense Input.
This pin senses the voltage via
an external resistor divider.
This pin provides a separate
path for drive current to be con-
nected to ground.
Switching Output.
5
FB
7
DRV
8
SW
ORDERING GUIDE
PIN CONFIGURATION
Model
Temperature
Range
Package
Option
Branding
Information
IN
IN
GND
COMP
1
2
TOP
VIEW*
ADP3089ACP -40°C to +85°C CSP-8 3×3 P7A
8
7
6
5
SW
DRV
GND
FB
3
4
* PIN’S UNDERSIDE
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 the device features proprietary ESD protection circuitry, permanent damage may oc-
cur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD
precautions are recommended to avoid performance degradation or loss of functionality.
REV. PrE
–3–
京公网安备 11010802033920号
EEWORLD
