General Description

The APW7108 is a dual-channel, constant on-time, and synchronous PWM controller which drives dual N-channel MOSFETs for each channel. The APW7108 steps down high voltage of a battery to generate low-voltage chipset or RAM supplies in notebook computers.

Features

· Adjustable Output Voltage up to 5.5V

- 0.9V Reference Voltage

- ±1% Accuracy Over Temperature

· Operates from an Input Battery Voltage Range of 5V to 24V or from 3.3V/5V System Rail

· Power-On-Reset Monitoring on VCC Pin

· Selectable Forced PWM or Automatic PFM/PWM Mode

· Constant-On-Time Control Scheme

- Switching Frequency Compensation for PWM Mode

- Constant Switching Frequency (CH1: 345kHz, CH2: 255KHz) in PWM Mode with DC Output Current

· Excellent Line and Load Transient Responses

· Adjustable Soft-Start and Soft-Stop

· Power-Good Outputs for both Channels

· Adjustable Current-Limit Protection

- Using Sense Resistor or MOSFET’s RDS(ON)

· 115% Over-Voltage Protection

- No Negative Output Voltage Occurred

· 70% Under-Voltage Protection

· Adaptive Dead-Time Control

- Sensing G-to-S Voltage of Power MOSFETs

· Shutdown Control for both Channels

· 28-pin SSOP (SSOP-28) and 4mmx4mm 24-lead QFN (QFN4x4-24) Packages

· Lead Free and Green Devices Available (RoHS Compliant)

Applications

· Note Book Computers

- Chipset/RAM Supplies as low as 0.9V

- 1.8V and 2.5V Supplies

· Step-Down Converters Requiring High Efficiency