Fixed Ratio High Power Inductorless (Charge Pump) DC/DC Controller

The LTC7820 is a fixed ratio high voltage high power switched capacitor/charge pump controller. The device includes four N-channel MOSFET gate drivers to drive external power MOSFETs in voltage divider, doubler or inverter configurations. The device achieves a 2:1 step-down ratio from an input voltage as high as 72V, a 1:2 step-up ratio from an input voltage as high as 36V, or a 1:1 inverting ratio from an input voltage up to 36V. Each power MOSFET is switched with 50% duty cycle at a constant pre-programmed switching frequency. System efficiency can be optimized to over 99%. The LTC7820 provides a small and cost effective solution for high power, non-isolated intermediate bus applications with fault protection.

The LTC7820 switching frequency can be linearly programmed from 100 kHz to 1MHz. The device is available in a thermally enhanced 28-lead QFN package with some no-connect pins for high voltage compatible pin spacing.

Applications

* Bus Converters

* High Power Distributed Power Systems

* Communications Systems

* Industrial Applications

* Low Profile, High Power Density, Capable of 500W+* Soft Switching: 99% Peak Efficiency and Low EMI* VIN Max for Voltage Divider (2:1): 72V* VIN Max for Voltage Doubler (1:2)/Inverter (1:1): 36V* Wide Bias VCC Range: 6V to 72V* Soft Startup into Steady State Operation* 6.5V to 40V EXTVCC Input for Improved Efficiency* Input Current Sensing and Overcurrent Protection* Wide Operating Frequency Range: 100kHz to 1MHz* Output Short-Circuit/OV/UV Protections with Programmable Timer and Retry* Thermally Enhanced 28-Pin 4mm × 5mm QFN Package