GENERAL INFORMATION:
The “FIL” Series is a non-isolated
precision filament supply. This line of regulated
DC-DC converters addresses the needs of the
high precision and high stability power supply
user. Designed and built utilizing a state-of-the-art
power-conversion topology, these units feature
surface-mount technology and encapsulation
techniques that provide high reliability and
low cost. The “FIL” Series supply
allows users to properly operate the filament
to maximize performance and extend its life.
DESIGN METHODOLOGY:
The “FIL” converters utilize a dual-ended forward converter topology
with a nominal switching frequency of <100kHz. A precision reference is
provided so the remote control can program the power supply for a specific
current or voltage. A constant-frequency PWM regulation system controls the
MOSFET push-pull power stage.
INPUT AND OUTPUT RANGE:
The “FIL” Series
is
designed
for
full
power
operation
at
+24VDC ±10%.
Output
voltage
is
adjustable
from
0
to
5VDC.
As
the
output
voltage
is
reduced
towards
0,
the
maximum
current
capability
remains
unchanged.
OUTPUT
VOLTAGE AND CURRENT MONITORS:
The “FIL” Series features a voltage
monitor on pin 14, referenced to Signal Ground
pin 5. The scale factor is 10V = 5.0V out.
The “FIL” Series also features an output current monitor.
Current can be monitored by reading the voltage appearing between
Output Monitor pin 3 and Signal Ground pin 5. Accuracy for Imon is 0.1%
with a temperature coefficient of 15 ppm in current mode. |
REMOTE
CONTROL:
The “FIL” Series is remotely programmed with 0 to +10.0 VDC to
produce an output voltage or current. Input may be from a control voltage,
DAC, variable or fixed resistor.
STANDBY
MODE:
The “FIL” converters also have
an enable function. When the enable is TTL
0 (<+0.7V Isink=1mA), the converter is
in a standby mode and input current is reduced
to <30 mA. All functions other than the
internal reference are shut down. If the
enable pin is left unconnected or TTL 1.
The open-circuit output voltage from the
Enable pin is <+5VDC. In the inhibit/disable
mode, 1 mA will have to be sunk for proper
shutdown.
MECHANICAL:
“FIL” Series converters are in PCB-mountable plastic cases requiring
a footprint of 7.05 in² and only 6.35 in³ of volume. Mounting plates and brackets
are available for chassis mounting. See Application Note
6 for thermal considerations and mounting configurations. All models
are available with optional six-sided wrap-around Mu-Metal Shielding.
ENVIRONMENTAL:
The “FIL” Series provides full
power operation at case temperatures from
+10 to +45°C. All units receive a 24-hour
burn-in prior to final testing. Extended
temperature range is available along with
other enhanced capabilities. Please contact
the factory.
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