Synchronizing Current Mode PWM for Subscriber Line Interface Circuits (SLICs)

The ISL6401 adjustable frequency, low power, pulse width modulating (PWM) current mode controller is designed for a wide range of DC-DC conversion applications including boost, flyback, and isolated output configurations. The device is optimized to provide a high performance, low-cost solution for Ringing SLIC (RSLIC) ring and talk power supplies. An integrated inverter allows for easy design of negative voltage regulation circuits with a minimal amount of external components. Internal soft start minimizes start-up stress without any external components. Peak current mode control effectively handles Ring trip transients and provides inherent over-current protection.

Features

? Positive and Negative Output Regulation

? Starting Supply Current . . . . . . . . . . . . . . . . . 100μA (typ.)

? Quiescent Current . . . . . . . . . . . . . . . . . . . . . . 55μA (typ.)

? Output Frequency Range. . . . . . . . . . . . 50kHz to 600kHz

? External Clock Synchronization

? Fast Transient Response with Peak Current Mode Control

? Internal Soft-Start

? Drives N-Channel MOSFET

? Logic Level Shutdown

? Leading Edge Blanking

? 1 Tolerance Voltage Reference Over Line and Temperature

Applications

? VoIP/VoDSL Ringer and Off-Hook Voltage Generators

? Multi-Output Flyback Supplies

? Cable and DSL Modems

? Set-Top Boxes

? Wireless Local Loops

? LMDH and FTTH Supplies

? Boost Regulators

? Routers