L6727 datasheet(9/34 Pages) STMICROELECTRONICS

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L6727

Device description

Doc ID 12933 Rev 4

9/34

Device description

L6727 is a single-phase PWM controller with embedded high-current drivers that provides

complete control logic and protections to realize in an easy and simple way a general DC-

DC step-down converter. Designed to drive N-channel MOSFETs in a synchronous buck

topology, with its high level of integration this 8-pin device allows reducing cost and size of

the power supply solution.

L6727 is designed to operate from a 5 V or 12 V supply bus. Thanks to the high precision

0.8V internal reference, the output voltage can be precisely regulated to as low as 0.8 V with

±1 % accuracy over line and temperature variations (between 0 °C and +70 °C).

The switching frequency is internally set to 300 kHz.

This device provides a simple control loop with a voltage-mode error-amplifier. The error-

amplifier features a 15 MHz gain-bandwidth product and 8V/µs slew rate, allowing high

regulator bandwidth for fast transient response.

To avoid load damages, L6727 provides over current protection as well as over voltage,

under voltage and feedback disconnection protection. When the device is supplied from 5 V,

over current trip threshold is programmable by a simple resistor. Output current is monitored

across Low-side MOSFET RdsON, saving the use of expensive and space-consuming sense

resistor. Output voltage and feedback disconnection are monitored through FB pin.

L6727 implements soft-start increasing the internal reference from 0 V to 0.8 V in 5.1 ms

(typ) in closed loop regulation. Low-side-less feature allows the device to perform soft-start

over pre-biased output avoiding high current return through the output inductor and

dangerous negative spike at the load side.

L6727 Fiches technique(PDF) 9 Page - STMicroelectronics