TPS3839: TPS3839 with load working abnormally

Gust Zhang

Part Number: TPS3839
Other Parts Discussed in Thread: TLV803E

Hi Team,

My customer find that TPS3839 connect load has been abnormal. Load is a DSP, RST connects DSP directly. The part schematic as follow.

VDD=1.25V

RST=1.25(Without load)

RST=1.02(with load).

The problem is that chip works abnormally with load. why cause this problem?

Gust

over 3 years ago

0 Ben C over 3 years ago

TI__Mastermind 28445 points

Hi Gust,

How much load is being applied to the RST pin? Can the customer disconnect the load and measure the RST pin?

Ben

0 Gust Zhang over 3 years ago in reply to Ben C

TI__Expert 5811 points

Hi Ben,

The load is only one and it is a DSP. My customer can disconnect the load and measure the RST pin. RST=1.25(disconnect load) and RST=1.02(connect load).

Gust

0 Ben C over 3 years ago in reply to Gust Zhang

TI__Mastermind 28445 points

Hi Gust,

Based on what you said, the load is apparently too high for the push-pull output. Is the customer open to using an open drain output instead of a push-pull output? The TLV803E is another option for the customer with the same package and pinout but has an open drain output on /RESET pin. The /MR pin can just float or tied directly to VDD.

Ben

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TPS3839: TPS3839 with load working abnormally