MCP16311-ESLASHMS datasheet(17/40 Pages) MICROCHIP

Part #	MCP16311-E/MS

Description	30V Input, 1A Output, High-Efficiency, Integrated Synchronous Switch Step-Down Regulator

PDF	40 Pages

Scroll/Zoom	100%

Manufacturer	MICROCHIP [Microchip Technology]

Direct Link	http://www.microchip.com

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17 / 40 page

 2013-2014 Microchip Technology Inc.

DS20005255B-page 17

MCP16311/2

4.2.5

HIGH-SIDE DRIVE

The MCP16311/2 features an integrated high-side

N-Channel MOSFET for high-efficiency step-down

power conversion. An N-Channel MOSFET is used for

its low resistance and size (instead of a P-Channel

MOSFET). The N-Channel MOSFET gate must be

driven above its source to fully turn on the device, result-

ing in a gate-drive voltage above the input to turn on the

high-side N-Channel. The high-side N-channel source

is connected to the inductor and boost cap or switch

node. When the high-side switch is off and the low-side

switch is on, the inductor current flows through the low-

side switch, providing a path to recharge the boost cap

from the boost voltage source. The voltage for the boost

cap is supplied from the internal regulator (VCC). An

internal boost blocking diode is used to prevent current

flow from the boost cap back into the regulator during

the internal switch-on time. If the boost voltage

decreases significantly, the low side will be forced low

for 90 ns in order to charge the boost capacitor.

MCP16311-E/MS Datasheet(PDF) 17 Page - Microchip Technology