why supervisor-TPS3700 output square wave when volage under UVLO?

[翔李]

hi,

The TI is so bad that i give up to look for them,so,thanks NXP-FSL for helping me.

I use tps3700 to supervisor 12V in the car,when voltage below 10V,the tps3700 must output 0 to the PNP+PMOS or DCDC ic.

when there is no load in the board,tps3700 work well,but,when the load is 12v@0.65A,tps3700 output square wave(between 0 to 10V change) while the voltage between 9.8V~10V.

also,if do not use tps3700,the pnp+pmos or DCDC ic work well.

The attachments are schematic diagram.

link:

why TPS3700 output square wave when volage under UVLO? - Supervisor and Reset IC Forum - Supervisor ...

[igorpadykov]

Hi Xiang

this supervisor has small threshold/hysteresis voltages so quite

susceptible to car voltage ripples, recommended to thoroughly filter

its input and power supply voltages.

Best regards

igor

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