M7085L-SM1-R datasheet(7/7 Pages) UTC

7 / 7 page

M7085

CMOS IC

UNISONICTECHNOLOGIESCO.,LTD

7 of 7

www.unisonic.com.tw

QW-R502-092, Ba

APPLICATION INFORMATION(Cont.)

P-Channel MOSFET Selection(Q1)

An external P-Channel power MOSFET must be used the UTC M7085 key selection criteria for the power for the

P-Channel are the maximum Drain-Source voltage (VDS) MOSFET are the gate threshold, VGS, the “ON” resistance,

RDS(ON) and its total gate charge.

The voltage across the PFET when it is turned off is equal to the sum of the input voltage and the diode forward

voltage. The VDS must be selected to provide some margin beyond the input voltage.

RDS(ON)determines the conduction losses for each switching cycle, the lower the ON resistance, the higher the

efficiency can be chivied.

A power MOSFET with lower gate charge can give lower switching losses but the fast transient can cause

unwanted EMI to the system. Compromise in between is required during the design stage. Keeping the gate

capacitance below 2000pF is recommended.

UTC assumes no responsibility for equipment failures that result from using products at values that

exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or

other parameters) listed in products specifications of any and all UTC products described or contained

herein. UTC products are not designed for use in life support appliances, devices or systems where

malfunction of these products can be reasonably expected to result in personal injury. Reproduction in

whole or in part is prohibited without the prior written consent of the copyright owner. The information

presented in this document does not form part of any quotation or contract, is believed to be accurate

and reliable and may be changed without notice.

M7085L-SM1-R 数据表(PDF) 7 Page - Unisonic Technologies