Quote from: Je Gold on December 27, 2006, 07:44:11 AM
There are 2 application notes from NXP(Philips) which describes using the MCB900 with a simple transistor circuit and prog90x.hex bridge code. AN10258_1.pdf and AN10258_2.pdf. AN10258_2.pdf seems to be the final and the MCB900 uses a NPN transistor to switch Vdd on the target being programmed.....
The NPN does not make a good Vdd led light...... and the prog90x.hex code programs the Vdd switch (p2.3) as quasi-bidirectional (weak hi-side drive)..... and Vbe drop of ~0.6v
A classic load switch NPN-PNP circuit overcomes the problems of weak drive from p2.3 and has less voltage drop across the switch.
See the Vdd switch circuit attached.... note the resistor values may need to be adjusted to suit the transistors used.
Perhpas NXP (Philips) or some one else on this forum may consider a complete ICP application with improvements gained over the last year... We know ICP is an issue for many first time users (just look how many forum members post questions on ICP).
Regards
Joe
hello friend what are the latest ICP improvements? I am trying to get some detailed information so please help if you ca