AIC1570
5-bit DAC, Synchronous PWM Power Regulator
with LDO and Linear Controller
DS-1570-00
www.analog.com.tw
1
FEATURES
Compatible with HIP6018.
Provides 3 Regulated Voltages for Micro-
processor Core, Clock and GTL Power.
Simple Voltage-Mode PWM Control.
Dual N-Channel MOSFET Synchronous Driver.
Operates from +3.3V, +5V and +12V Inputs.
Fast Transient Response.
Full 0% to 100% Duty Ratios.
1.0% Output Voltage for VCORE and
2.0%
Output Voltage Reference for VCLK and VGTL.
TTL Compatible 5-bit Digital-to-Analog Core
Output Voltage Selection. Range from 1.3V to
3.5V.
0.1V Steps from 2.1V to 3.5V.
0.05V Steps from 1.3V to 2.05V.
Adjustable Current Limit without External Sense
Resistor.
Microprocessor Core Voltage Protection against
Shorted MOSFET.
Power Good Output Voltage Monitor.
Over-Voltage and Over-Current Fault Monitors.
200KHz Free-Running Oscillator Programmable
up to 350KHz.
APPLICATIONS
Full Motherboard Power Regulation for
Computers.
DESCRIPTION
The AIC1570 combines a synchronous voltage
mode controller with a low dropout linear regulator
and a linear controller as well as the monitoring and
protection functions in this chip. The PWM
controller regulates the microprocessor core
voltage with a synchronous rectified buck converter.
The linear controller regulates power for the GTL
bus and the linear regulator provides power for the
clock driver circuit.
An integrated 5 bit D/A converter that adjusts the
core PWM output voltage from 2.1V to 3.5V in 0.1V
increments and from 1.3V to 2.05V in 0.05V
increments. The linear regulator uses an internal
driver device to provide 2.5V2.5%. The linear
controller drives with an external N-channel
MOSEFET to provide 1.5V2.5%.
This chip monitors all the output voltages. Power
Good signal is issued when the core voltage is
within 10% of the DAC setting and the other levels
are above their under-voltage levels. Over-voltage
protection for the core output uses the lower N-
channel MOSFET to prevent output voltage above
115% of the DAC setting.
The PWM over-current function monitors the output
current by using the voltage drop across the upper
MOSFET's R
DS(on)
, eliminating the need for a
current sensing resistor.
AIC1570
2
ORDERING INFORMATION
ORDER NUMBER
PIN CONFIGURATION
AIC1570-XX
AIC1570CS
(SO24)
PACKAGING TYPE
S: SMALL OUTLINE
TEMPERATURE RANGE
C: 0
C~+70C
1
3
4
2
5
7
6
8
9
10
11
12
VID0
VID4
VID3
VID2
VCC
VID1
RT
PGOOD
SS
FAULT
VIN2
FB2
16
15
24
22
23
21
20
19
17
18
14
13
LGATE
UGATE
PHASE
VSEN
PGND
OCSET
FB1
GATE3
COMP1
FB3
VOUT2
GND
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, V
CC
........................................................................................ +15V
PGOOD, FAULT and GATE Voltage
.................................. GND -0.3V to V
CC
+0.3V
Input, Output , or I/O Voltage ........................................................ GND -0.3V to 7V
Recommended Operating Conditions
Supply Voltage; VCC
........................................... +12V10%
Ambient temperature Range
........................................ 0
C~70C
Junction Temperature Range ....................................... 0
C~100C
Thermal Information
Thermal Resistance,
JA
SOIC package
........................................................... 100
C/W
SOIC package (with 3in
2
of copper)
.................................. 90
C/W
Maximum Junction Temperature (Plastic Package) ................................ 150
C
Maximum Storage Temperature Range ..................................... -65
C ~ 150C
Maximum Lead Temperature (Soldering 10 sec) ................................... 300
C
TEST CIRCUIT
Refer to APPLICATION CIRCUIT.
AIC1570
3
ELECTRICAL CHARACTERISTICS
(V
cc
=12V, T
J
=25
C, Unless otherwise
specified)
PARAMETER
TEST CONDITIONS
SYMBOL
MIN.
TYP.
MAX.
UNIT
VCC SUPPLY CURRENT
Supply Current
UGATE, LGATE, GATE3 and
VOUT2 open
I
CC
1.8
5
mA
POWER ON RESET
Rising VCC Threshold
V
OCSET
=4.5V
VCC
THR
8.6
9.5
10.4
V
Falling VCC Threshold
V
OCSET
=4.5V
VCC
THF
8.2
9.2
10.2
V
Rising VIN2 Under-Voltage
Threshold
VIN2
THR
2.5
2.6
2.7
V
VIN2 Under-Voltage
Hysteresis
VIN2
HYS
130
mV
Rising V
OCSET1
Threshold
V
OCSETH
1.3
V
OSCILLATOR
Free Running Frequency
RT=Open
F
170
200
230
KHz
Ramp. Amplitude
RT=open
V
OSC
1.3
V
P-P
REFERENCE AND DAC
DAC (VID0~VID4) Input Low
Voltage
VID
L
0.8
V
DAC (VID0~VID4) Input
High Voltage
VID
H
2
V
DACOUT Voltage Accuracy
VDAC=1.8V~3.5V
-1.0
+1.0
%
FB2 Reference Voltage
V
REF2
1.240
1.265
1.290
V
FB3 Reference Voltage
V
REF3
1.250
1.275
1.300
V
LINEAR REGULATOR
Regulation
10mA<I
OUT2
<150mA
-1
+1
%
Under-Voltage Level
FB2 falling
FB2
UV
70
82
%
Over-Current Protection
430
570
mA
Over-Current Protection
During Start-up
750
mA
AIC1570
4
ELECTRICAL CHARACTERISTICS
(Continued)
PARAMETER
TEST CONDITIONS
SYMBOL
MIN.
TYP.
MAX.
UNIT
LINEAR CONTROLLER
Regulation
0 < I
GATE3
< 10mA
-2.5
+2.5
%
Under-Voltage Level
FB3 falling
FB3
UV
70
80
%
PWM CONTROLLER ERROR AMPLIFIER
DC GAIN
76
dB
Gain Bandwidth Product
GBWP
11
MHz
Slew Rate
COMP1=10pF
SR
6
V/
S
PWM CONTROLLER GATE DRIVER
Upper Drive Source
VCC=12V, V
UGATE
=11V
R
UGH
5.2
6.5
Upper Drive Sink
VCC=12V, V
UGATE
=1V
R
UGL
3.3
5
Lower Drive Source
VCC=12V, V
LGATE
=11V
R
LGH
4.1
6
Lower Drive Sink
VCC=12V, V
LGATE
=1V
R
LGL
3
5
PROTECTION
V
OUT1
Voltage Over-Voltage
Trip
VSEN Rising
OVP
112
115
118
%
OCSET Current Source
V
OCSET
=4.5V
DC
I
OCSET
170
200
230
A
FAULT Sourcing Current
V
FAULT
=10V
I
OVP
10
16
mA
Soft-Start Current
I
SS
11
A
Chip Shutdown Soft Start
Threshold
1.0
V
POWER GOOD
V
OUT1
Upper Threshold
VSEN Rising
109
110.5
112
%
V
OUT1
Under-Voltage
VSEN Falling
90.5
92
93.5
%
V
OUT1
Hysteresis
(VSEN/DACOUT)
Upper and Lower
Threshold
3
%
P
GOOD
Voltage Low
I
PGOOD
=-4mA
V
PGOOD
0.5
V
AIC1570
5
TYPICAL PERFORMANCE CHARACTERISTICS
U
GATE
L
GATE
U
GATE
L
GATE
FIG.1 The gate drive waveforms
I
CC
(mA)
Switching Frequency (KHz)
100
150
200
250
300
350
400
0
10
20
30
40
50
60
C
UGATE
=C
LGATE
=C
GATE
V
CC
=12V
C
GATE
=5000pF
C
GATE
=2000pF
C
GATE
=660pF
100
150
200
250
300
350
400
1
10
100
1000
10000
Resis
t
an
ce (
k
)
Switching Frequency (KHz)
R
T
Pull Down to GND
R
T
Pull Up to +12V
450
FIG. 2 Bias Supply Current VS. Frequency FIG. 3 R
T
Resistance VS. Frequency
SS (2V/div)
V
OUT3
(1V/div)
V
OUT2
(1V/div)
V
OUT
1
(1V/div)
PGOOD (5V/div)
VDAC=3.5V
VDAC=1.3V
VDAC=2V
SS
FIG.4 Soft Start Interval
with 3 Outputs and PGOOD FIG. 5 Soft Start Initiates PWM Output
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