The USB-MODEVM interface board can be powered from several different sources:

• USB
• 6 Vdc–10 Vdc AC/DC external wall supply (not included)
• Lab power supply

When powered from the USB connection, JMP6 must have a shunt from pins 1–2 (the default factory configuration). When powered from 6 V–10 Vdc, either through the J8 terminal block or J9 barrel jack, JMP6 must have a shunt installed on pins 2–3. If power is applied in any of these ways, onboard regulators generate the required supply voltages and no further power supplies are necessary.

If lab supplies are used to provide the individual voltages required by the USB-MODEVM interface, JMP6 must have no shunt installed. Voltages are then applied to J2 (+5VA), J3 (+5VD), J4 (+1.8VD), and J5 (+3.3VD). The +1.8VD and +3.3VD can also be generated on the board by the onboard regulators from the +5VD supply; to enable this configuration, the switches on SW1 must be set to enable the regulators by placing them in the ON position (lower position, looking at the board with text reading right-side up). If +1.8VD and +3.3VD are supplied externally, disable the onboard regulators by placing SW1 switches in the OFF position.

Each power-supply voltage has an LED (D1-D7) that lights when the power supplies are active.