QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 563
SINGLE AND DUAL MARGINING CONTROLLER
2
floating. Raising the In pin(s) above 2.0 V will cause
the power supply output voltage to increase by the
desired margin voltage. Lowering the In pin(s) below
0.6 V will cause the power supply output voltage to
decrease by the desired margin voltage.
When con-
nected to ‘trim’ pins on DC to DC modules, the po-
larity of the voltage margining may be inverted.
If the LTC2920 Vcc pin is connected to power sup-
plies that are compensated to be only ‘marginally sta-
ble,’ oscillations may be observed. If oscillations are
observed while margining a power supply, connect
the Vcc pin to the power supply using an axial lead
resistor instead of a wire. See the LTC2920 Data
Sheet for calculating the value of this resistor.
Figure 1. Proper Measurement Equipment Setup
