150V Low I, Synchronous Step-Down DC/DC Controller

The LTC3895 is a high performance step-down switching regulator DC/DC controller that drives an all N-channel synchronous power MOSFET stage that can operate from input voltages up to 140V. A constant frequency current mode architecture allows a phase-lockable frequency of up to 850kHz.

The gate drive voltage can be programmed from 5V to 10V to allow the use of logic or standard-level FETs to maximize efficiency. An integrated switch in the top gate driver eliminates the need for an external bootstrap diode. An internal charge pump allows for 100% duty cycle operation.

The low 40μA no-load quiescent current extends operating run time in battery-powered systems. OPTI-LOOP® compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The LTC3895 features a precision 0.8V reference and power good output indicator. The output voltage can be programmed between 0.8V to 60V using external resistors or pin-programmed for a fixed 5V or 3.3V.

Applications

* Automotive and Industrial Power Systems

* High Voltage Battery Operated Systems

* Telecommunications Power Systems

* Wide VIN Range: 4V to 140V (150V Abs Max)

* Wide Output Voltage Range: 0.8V to 60V

* Adjustable Gate Drive Level: 5V to 10V (OPTI-DRIVE)

* Low Operating IQ: 40μA (Shutdown = 10μA)

* 100% Duty Cycle Operation

* No External Bootstrap Diode Required

* Selectable Gate Drive UVLO Thresholds

* Onboard LDO or External NMOS LDO for DRVCC

* EXTVCC LDO Powers Drivers from VOUT

* Phase-Lockable Frequency (75kHz to 850kHz)

* Programmable Fixed Frequency (50kHz to 900kHz)

* Selectable Continuous, Pulse-Skipping or Low Ripple Burst Mode® Operation at Light Loads

* Adjustable Burst Clamp and Current Limit

* Adjustable or Fixed (5V/3.3V) Output Voltage

* Power Good Output Voltage Monitor

* Programmable Input Overvoltage Lockout

* 38-Lead TSSOP High Voltage Package