AIC1570
5-bit DAC, Synchronous PWM Power Regulator
with LDO and Linear Controller
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.
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 2.5V±2.5%. The linear
controller drives with an external N-channel
MOSEFET to provide 1.5V±2.5%.
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.
APPLICATIONS
Full
Motherboard
Power
Regulation
for
Computers.
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.
DS-1570-00
www.analog.com.tw
1
AIC [ ANALOG INTERGRATIONS CORPORATION ]
