AIC1567
5-bit DAC, Synchronous PWM Power Regulator
with Linear Controller
Analog Integrations Corporation
4F, 9 Industry E. 9th Rd, Science-Based Industrial Park, Hsinchu, Taiwan
DS-1567-01 012102
TEL: 886-3-5772500
FAX: 886-3-5772510
www.analog.com.tw
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FEATURES
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Switching Regulator and Low Dropout Linear
Regulator on single chip.
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Simple Voltage-Mode PWM Control.
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Dual N-Channel MOSFET Synchronous Drive.
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Fast Transient Response.
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1.0% 5-Bit Digital-to-Analog Output Voltage.
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Adjustable Current Limit Without External Sense
Resistor.
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Full 0% to 100% Duty Ratio.
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200KHz Free-Running Oscillator Programmable
up to 350KHz.
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Power-Good Output Voltage Monitor.
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Short Circuit Protection with Low Short Circuit
Output Current.
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TTL Compatible 5-bit Digital-to-Analog core
Output Voltage Selection, with range from 1.3V to
3.5V;
0.1V Steps from 2.0V to 3.5V
0.05V Steps from 1.3V to 2.0V
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APPLICATIONS
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Power Supply for Pentium II, Power PC and
Alpha Microprocessors.
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High-Power 5V to 3.xV DC/DC Regulators.
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Low-Voltage Distributed Power Supplies.
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DESCRIPTION
The AIC1567 is a high power, high efficiency
switching regulator controller optimized for high
performance microprocessor applications. It is
designed to drive two N-channel MOSFETs in a
standard synchronous buck topology.
Featuring a low dropout linear regulator and a
digitally programmable switching regulator, the
AIC1567 includes monitoring and protection
capabilities in addition to all the essential
synchronous PWM control functions.
The internal 5-bit Digital-to-Analog Converter
(DAC) adjusts the output voltage from 2.0V to
3.5V in 0.1V increments and 1.3V to 2.0V in
0.05V increments. The precision reference and
voltage-mode control can provide output
regulation within
1.0% over temperature and
line voltage shifts.
The AIC1567 includes an internal 200KHz free-
running oscillator that can be adjusted up to
350KHz. The resulting PWM duty ratio ranges
from 0% to 100%. The error amplifier features a
11MHz bandwidth and 6V/
S slew rate, which
enables high converter bandwidth for fast
transient response.
AIC1567
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ABSOLUTE MAXIMUM RATINGS
Supply Voltage, V
CC
....... ..................................... ... ... ... ... ........................................... 15V
Boot Voltage, V
BOOT
... ... ... ...................... ... ... ... ... ...................................................... 15V
Input, Output, or I/O Voltage ........ ... ............ ... ... ... ... ......... ....... GND - 0.3V to VCC+0.3V
ESD Classification
.............................. ... ... ... ......................... ... ......................... Class 2
Recommended Operating Conditions
Supply Voltage, V
CC
....... ...................... ... ... ... ... ... ... ............................. ... .......... 12V
10%
Ambient Temperature Range ....... ... ... ... ... ... ... ... ............................................ 0
C ~ 70
C
Maximum Operating Junction Temperature ......... ......... ............. ... .... ... ................... 100
C
Thermal Information
Thermal Resistance,
JA
(Typical, Note 1)
SOIC Package ........................ ... ............ ... ... ... ... ... ... ... ... ... ... ... ............ . 100
C/W
SOIC Package (with 3 in
2
of Copper) ... ... ... ... ... ... ... ... ... ... ... ... ... ......... .. 90
C/W
Maximum Junction Temperature (Plastic Package) ... .... ... ... ... ... ... .... ................... 150
C
Maximum Storage Temperature Range ... ... ... ... ... ... ... ... ..... ... ......... ......... -65
C~150
C
Maximum Lead Temperature (Soldering 10 sec) ... ... ... ... ... ... ... ... ... ... ......... ......... 300
C
Note 1: symbol
JA
is measured with the component mounted on an evaluation PC board in free air.
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TEST CIRCUIT
Refer to TYPICAL APPLICATION CIRCUIT.
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ELECTRICAL CHARACTERISTICS
(VCC= 12V, T
A
=25
C, unless otherwise
specified.)
PARAMETER
TEST CONDITIONS
SYMBOL
MIN.
TYP.
MAX.
UNIT
VCC Supply Current
Nominal Supply
UGATE Open
I
VCC
2
mA
Power-On Reset
V
CC
Threshold
V
OCSET
=4.5V
7
8.5
V
Rising V
OCSET
Threshold
1.26
V
Oscillator
Free Running Frequency
R
T
Open
170
200
230
KHz
Total Variation
6K
< R
T
<200K
-20
+20
%
Ramp Amplitude
R
T
Open
V
OSC
1.5
V
P-P
AIC1567
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ELECTRICAL CHARACTERISTICS
(Continued)
PARAMETER
TEST CONDITIONS
SYMBOL
MIN.
TYP.
MAX.
UNIT
Reference and DAC
DACOUT Voltage Accuracy
V
DAC
=1.8V ~3.5V
-1.0
+1.0
%
Error Amplifier
DC Gain
76
dB
Gain-Bandwidth Product
GBW
11
MHz
Slew Rate
SR
6
V/
S
Gate Driver
Upper Gate Source
R
UGATE
8.0
12
Upper Gate Sink
R
UGATE
5.5
10
Lower Gate Source
R
LGATE
8.0
12
Lower Gate Sink
R
LGATE
5.5
10
Protection
Over-Voltage Trip (V
SEN/DACOUT
)
106
115
125
%
OCSET Current Source
V
OCSET
=4.5VDC
I
OCSET
170
200
230
A
OVP Sourcing Current
V
VSEN
=5.5V, V
OVP
=0V
I
OVP
30
mA
Soft Start Current
I
SS
10
A
Soft Start Sink Current under
Current Limit
V
VSEN
=V
DAC
, V
OCSET
=5.0V,
V
PHASE
=0V,
V
FB
=VDAC=50mV
130
A
Soft Start Sink Current under
Hard Current Limit
V
VSEN
=0, V
OCSET
=5.0V,
V
PHASE
=0V, V
FB
=0V
65
mA
Power Good
Upper Threshold (V
VSEN
/V
DAC
) V
VSEN
Rising
106
114
%
Lower Threshold (V
VSEN
/ V
DAC
) V
VSEN
Falling
84
94
%
Hysteresis (V
VSEN
/ V
DAC
)
Upper and Lower Threshold
2
%
PGOOD Voltage Low
I
PGOOD
=5mA
V
PGOOD
0.5
V
Linear Regulator
VLFB Feedback Voltage
1.18
1.21
1.24
V
VLFB Bias Current
40
nA
LIDRI Sourcing Current
10
mA
Current Limiting Threshold
10
20
30
mV