Linear Technology Intoduces Synchronous No RSENSE Step-up Switching Regulator Controller

Linear Technology's LTC3813 is a synchronous No RSENSE step-up switching regulator controller that eliminates the boost diode and the heat sink normally required in medium to high power non-synchronous boost converters. The LTC3813 can regulate output voltages up to 100 V and has 1 ohm on-board dual n-channel MOSFET gate drivers that are capable of supplying high currents to slew large MOSFET gates quickly. This minimizes transition losses and allows paralleling of MOSFETs for higher current applications. In addition, the LTC3813 can regulate a 50 V at 4 A output with up to 97 % efficiency from a 10 V to 40 V input source.

Applications include automotive, avionics, telecom, networking equipment, servers, industrial control systems and basestations where a step-up DC/DC converter must deliver high power with low heat dissipation in a small package.

The LTC3813 uses current mode control and maintains ±0.875 % reference voltage accuracy over an operating temperature range of -40°C to 85°C.

The LTC3813 uses a constant, off-time peak current control architecture and has a high bandwidth (25 MHz) error amplifier that provides very fast line and load transient response. The constant off-time current mode architecture provides accurate cycle-by-cycle current limit protection.

The operating frequency is selected by an external resistor from 100 kHz to 1 MHz, which is also compensated for VIN variations and can be synchronized to an external clock for noise sensitive applications. The LTC3813 has a programmable soft-start, programmable undervoltage lockout and a power good signal that monitors the output voltage.

The LTC3813 is offered in the SSOP-28 package, which provides three unconnected pins between adjacent high and low voltage pins for extra PC board trace clearance, compliant with circuit board design standard IPC-2221 regarding high voltage pin spacing.