Programmer And Target System Are Independently Powered; Overview - Equinox Systems PPM3 MK2 User Manual

4.9 Programmer and Target System are independently powered

4.9.1 Overview

In this scenario, the programmer is powered from a completely independent supply to the Target
System. The programmer must be powered via one of the 'DC Power Connectors' on the rear panel
at 9.0 – 12.0V. The Target System is powered from an external power supply in the range of 3.0 to
5.0V. The Programmer_Vcc output must NOT be connected to the Target_Vcc line in this scenario.
Fig. 4.9.1 Programmer and Target System are independently powered
Explanation of operation:
•
The programmer is always powered ON
•
The 'Vcc Option Link' is removed
•
LK1 connection is removed (ie. Programmer and Target Vcc are disconnected)
•
The programmer must supply the same voltage as the Target_Vcc to the Programmer 'I/O Level
Converter Circuitry'.
•
The Target Power Supply should be switched OFF before the ISP cable is plugged into it
•
The programmer does not draw any current from the Target System during programming
•
When programming is complete, the Target System should be powered OFF and then the ISP
cable removed
Warning!
•
The voltage applied to the programmer via the ISP cable must be between 3.0 and 5.0V as
this voltage is used to drive the programmer I/O Stage. A 6V2 5W zener diode is internally
connected across the programmer supply to protect against over-voltage.
•
The Programmer and Target Vcc must be physically disconnected by cutting the Vcc signal
in the ISP cable if necessary.
PPM3 MKII Programmer - User Guide - V1.04 - 10
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