4.5-75V Wide Vin, Current Mode Non-Synchronous Buck Controller

The LM5088 high voltage non-synchronous buck

controller features all the necessary functions to implement an efficient,

high-voltage buck converter using a minimum number of external components. The

LM5088 can be configured to operate over an ultra-wide input voltage range of 4.5 V

to 75 V. This easy-to-use controller includes a level-shifted gate driver capable of

controlling an external N-channel buck switch. The control method is based upon peak

current mode control utilizing an emulated current ramp. The use of an emulated

control ramp reduces noise sensitivity of the pulse-width modulation circuit,

allowing reliable control of very small duty cycles necessary in high input voltage

and low output voltage applications. The LM5088 switching frequency is programmable

from 50 kHz to 1 MHz.

The LM5088 is available in two versions: The

LM5088-1 provides a ±5% frequency dithering function to reduce the conducted and

radiated EMI, while the LM5088-2 provides a versatile restart timer for overload

protection. Additional features include a low dropout bias regulator, tri-level

enable input to control shutdown and standby modes, soft start, and oscillator

synchronization capability. The device is available in a thermally enhanced 16-pin

HTSSOP package.