LM5088 Wide Input Range Non-Synchronous Buck Controller from the PowerWise® Family

Features:

Emulated current mode control
Drives external high-side N-channel MOSFET
Ultra-wide input voltage range from 4.5V to 75V
Low IQ Shutdown and Standby modes
High duty cycle ratio feature for reduced dropout voltage
Spread spectrum EMI reduction (LM5088-1)
Hiccup timer for overload protection (LM5088-2)
Adjustable output voltage from 1.205V with 1.5% feedback reference accuracy
Wide bandwidth error amplifier
Single resistor oscillator frequency setting
Oscillator synchronization capability
Programmable soft-start
High voltage, low dropout bias regulator
Thermal shutdown protection

Description:

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 4.5V to 75V. 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/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 TSSOP-16EP pin package.