Byron Jeff's Trivial HVP Programmer

This is a schematic for a trivial Tait style programmer that does high voltage programming (HVP). With a single IC and a handful of resistors and a single transistor, this is one of the most simple programmers that you'll find.

Release Notes

  • NOTE!: The schematic above has not been updated to reflect the new long cable termination scheme. Be sure to incorporate the AC termination described to the clock line.

  • Nearly everything described for the TLVP programmer applies here. So I'll not repeat that documentation.
  • The most critical change is that the MCLR pin in inverted. So it is crucial that your programming software be configured to invert that pin.
  • For both the 16F87X and 16F62X parts the +13V isn't manditory. The programming specifications for both parts states that HVP mode is entered if Vpp is at least 3.5V above Vdd. So for a Vdd of +5 only 8.5V is required. However if you want this programmer to be compatible with other PIC parts (such as the 16F84) then the 13V specified is required. Be sure to read your programming specifications sheet for your part if you decide to lower the Vpp voltage.
  • I haven't personally tested this design yet. I have had a couple of successful reports so I feel comfortable releasing this. Please post to the forum if you have issues or successes with this design.