Power Supply - Lexicon 960L Service Manual

960L Multi-Channel Digital Effects System Service Manual

Power Supply

Power conditioning for the Analog Input card involves local filtering and regulation of supplies from the
backplane.
The main 5VD from the backplane is used by the fpga and the digital sections of the A/D converters.
The 12V supplies from the backplane (+12VSUP/-12VSUP) are filtered by FB1/FB2 and associated
capacitors to supply +/-12V to the analog op-amps. +12VSUP also supplies U3 through a string of 5
dropping diodes to provide regulated +5VA for the A/D converters, which consume 4*130=520mA
maximum. Diodes D7,D8 prevent large differences from existing between the 5V pins of the converters.
Dropping diodes in series with U3 reduces the operating voltage, resulting in cooler operation.
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