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