ICSP A PIC16F628

[G7LQY]

i fear you are , may be, complicating the design. even smd chips could well be managed with original pcb using dip converter and can be plugged into a dip socket. as such they can be progranned ouside with help of breadboard and 5 wires connecting to programmer.

Hi
I know that i could do it that way, but i am doing a new artwork for a new pcb and i wish to use smd chips.
Would you agree that the circuit i posted would work to prog a PIC in circuit ?

Thanks
Howard

[mvs sarma]

i feel it should work , but we need to be sure that the electrolytic caps should not trouble you

of course we can remove them , program and place later.

[G7LQY]

i feel it should work , but we need to be sure that the electrolytic caps should not trouble you
of course we can remove them , program and place later.

Why would the electrolytic cap(C2) trouble me, i thought that D1 was there to stop the VDD getting to the cap ?.
Do you think that there is no need for R2 and R3 going to IC1(UDN2982SLW) which is NOT powered when using ICSP ?.

Thanks
Howard

[mvs sarma]

There i a stipulatio that the Vpp and Vdd should a have time difference not exceeding xx uS. If we have large electrolytic capacitor across the Vdd, tyhe supply is from PICKIT the Vdd cant raise that fast and so err would be reported. I saw this topic and was in fact searching for the source so that i could quote. Sooner i would give that reference.