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TPL9201 Relay Driver not responding

Other Parts Discussed in Thread: TPL9201

I'm using the TPL9201 relay driver, and they don't respond at all. I've got 12V input on pin 19, 5V out on pin 18 and 6.5V out on pin 13 (a no-connect). RST on pin 14 is floating, but with a pull up to 5V it goes to 5V.

I get no response at all when trying to set one of the output pins via the serial input. I also get no output when I pull EN1 (pin 12) to 5V. Documentation says that pulling this line high should turn OUT1 (pin 2) on. I have a 2k pullup on that pin, and it always remains high.

Anyone use this chip at all? I've seen some comments about it being hard to use, but setting an input line high should always be a first check that the hardware itself is working.

  • Joe,

    The RST line is an output and input. The RST line must be high (by a pull up resistor) for the drivers to be enabled.
    EN1 is the easiest way to turn on an output for debugging.

    The outputs are sink drivers so a load must be present from the output to some higher voltage.

    Regards,
    Ron Michallick