Features

• Wide V_IN + |V_OUT^–| Range: 4V to 140V (150V Abs Max)
• Wide Output Voltage Range: –60V to –0.8V
• Ground-Referenced Control / Interface Pins
• Adjustable Gate Drive Level 5V to 10V (OPTI-DRIVE)
• Integrated Bootstrap Diode
• Low Operating I_Q: 40μA (Shutdown = 10μA)
• Selectable Gate Drive UVLO Thresholds
• Onboard LDO or External NMOS LDO for DRV_CC
• EXTV_CC LDO Powers Drivers from Output
• 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
• Power Good Output Voltage Monitor
• Programmable Input Overvoltage Lockout
• 38-Lead TSSOP High Voltage Package

Typical Application

Description

The LTC®3896 is a high performance inverting DC/DC switching regulator controller that drives an all N-channel synchronous power MOSFET stage. It converts a wideranging positive input voltage source to a regulated negative output that can be as much as 60V below ground. The input can operate from a voltage as low as 4V and as high as 140V – |V_OUT^–|.

The LTC3896 contains true ground-referenced RUN, PLLIN and PGOOD pins, eliminating the need for external discrete level-shifting components to interface with the LTC3896.

A constant frequency current mode architecture allows a phase-lockable frequency of up to 850kHz. 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 LTC3896 features a precision 0.8V reference and power good output indicator. The soft-start (SS) pin ramps the output voltage during start-up.