Features

• 5-Bit Digitally Programmable 1.3V to 3.5V Fixed Output Voltage, VRM 8.4 Compliant
• Fast Transient Response: 0% to 100% Duty Cycle
• Phase Lead Compensation for Remote Sensing
• Overtemperature Protection
• Flags for Power Good and Overvoltage Fault
• 19A Output Current Capability from a 5V Supply
• Dual N-Channel MOSFET Synchronous Driver
• Initial Output Accuracy: ±1.5%
• Excellent Output Accuracy: ±2% Typ Over Line, Load and Temperature Variations
• High Efficiency: Over 95% Possible
• Adjustable Current Limit Without External Sense Resistors
• Available in 2O-Lead SSOP and SW Packages

Typical Application

Description

The LTC1753 is a high power, high efficiency switching regulator controller optimized for 5V input to a digitally programmable 1.3V-3.5V output. The internal 5-bit DAC programs the output voltage from 1.3V to 2.05V in 50mV increments and from 2.1V to 3.5V in 100mV increments. The precision internal reference and an internal feedback system provide an output accuracy of ±1.5% at room temperature and typically ±2% over temperature, load current and line voltage shifts. The LTC1753 uses a synchronous switching architecture with two external N-channel output devices, providing high efficiency and eliminating the need for a high power, high cost P-channel device. Additionally, it senses the output current across the on-resistance of the upper N-channel FET, providing an adjustable current limit without an external low value sense resistor.

The LTC1753 free-runs at 300kHz and can be synchronized to a faster external clock if desired. It provides a phase lead compensation scheme and under harsh loading conditions, the PWM duty cycle can be momentarily forced to 0% or 100% to reduce the output voltage recovery time.