The PWS740 is a multichannel, isolated DC-to-DC
converter with a 1500VAC continuous isolation rating.
The outputs track the input voltage to the converter
over the range of 7 to 20VDC. The converter’s
modular design, comprising three components, minimizes
the cost of isolated multichannel power for the
user.
The PWS740-1 is a high-frequency (400kHz nominal)
oscillator/driver, handling up to eight channels. This
part is a hybrid containing an oscillator and two power
FETs. It is supplied in a TO-3 case to provide the
power dissipation necessary at full load. Transformer
impedance limits the maximum input current to about
700mA at 15V input, well within the unit’s thermal
limits. A TTL-compatible ENABLE pin provides output
shut-down if desired. A SYNC pin allows synchronization
of several PWS740-1s.
The PWS740-2 is a trifilar-wound isolation transformer
using a ferrite core and is encapsulated in a
plastic package, allowing a higher isolation voltage
rating. One PWS740-2 is used per isolated channel.