LTC3721-1 Push-Pull PWM Controller UFEATURESDESCRIPTIO ■ High Efficiency Push-Pull PWM The LTC®3721-1 push-pull PWM controller provides all of ■ 1.5A Sink, 1A Source Output Drivers the control and protection functions necessary for com- ■ Adjustable Push-Pull Dead-Time pact and highly efficient, isolated power converters. High ■ Adjustable System Undervoltage Lockout and integration minimizes external component count, while Hysteresis preserving design flexibility. ■ Adjustable Leading Edge Blanking The robust push-pull output stages switch at half the ■ Low Start-Up and Quiescent Currents oscillator frequency. Dead-time is independently pro- ■ Current Mode Operation grammed with an external resistor. A UVLO program input ■ Single Resistor Slope Compensation provides precise system turn-on and turn off voltages. The ■ VCC UVLO and 25mA Shunt Regulator LTC3721-1 features peak current mode control with pro- ■ Programmable Fixed Frequency Operation to 1MHz grammable slope compensation and leading edge ■ Soft-Start, Cycle-by-Cycle Current Limiting and blanking. Hiccup Mode Short-Circuit Protection ■ 5V, 15mA Low Dropout Regulator The LTC3721-1 features extremely low operating and ■ 16-Pin SSOP and (4mm start-up currents and reliable short-circuit and × 4mm) QFN Packages overtemperature protection. The LTC3721-1 is offered in U 16-pin SSOP and (4mm × 4mm) QFN packages. APPLICATIO S , LTC and LT are registered trademarks of Linear Technology Corporation. ■ Telecommunications, Infrastructure Power Systems ■ Distributed Power Architectures ■ Server Power Supplies ■ High Density Power Modules UTYPICAL APPLICATIOIsolated Push-Pull Converter VIN VOUT + UVLO DRVA FROM AUXILIARY DRVB WINDING V CS CC DPRG RCS VREF LTC3721-1 CT VREF RLEB VOUT VOUT SS COMP V+ RTOP COLL RREF LT1431 FB GND COMP RMID GND-F GND-S 37211 TA01 sn37211 37211fs 1
