BQ2947: if (V4–V3), (V3–V2), (V2–V1), and (V1–VSS) < VOV, what's the Vout range?

Harry Zhang13

Part Number: BQ2947

we use BQ294705, if there is no OV, what's the VOUT range, is it 400mV max? do you think we have risk if we use VGS(th)min = 0.5V?

over 3 years ago

0 Harry Zhang13 over 3 years ago

Intellectual 495 points

do you think we have risk if we use Q51 VGS(th)min = 0.5V?

0 WM5295 over 3 years ago in reply to Harry Zhang13

TI__Guru 54715 points

Hi Harry,

The VOUT specification noted is with the OUT pin sinking 100 uA. If there is less current into the pin the voltage will be lower. The Q51 should not have a path to provide current and Vgsth min is likely specified at some small drain current, but check its leakage specifications and consider leakage possibilities on the board assembly. You may want a pull down resistor as shown in https://www.ti.com/document-viewer/BQ2947/datasheet/GUID-82572ECF-9BB9-45D8-883F-513B6F6D428B#TITLE-SLUSB15SLUSB158872 to avoid voltage developed by leakage or when the BQ2947 is not powered before assembly of the cells to board.

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BQ2947: if (V4–V3), (V3–V2), (V2–V1), and (V1–VSS) < VOV, what's the Vout range?