REMOTE CONTROL:
The “A” Series is remotely programmed with 0 to +5 VDC
to produce an output voltage. Input may be from a control
voltage, a DAC, or from a variable or fixed resistor. On a
negative output converter the programming logic of the remote
adjust would be inverted, i.e.: +5 to 0VDC. Connections are on
the converter for the internal reference, analog remote adjust
and the signal ground. The reference is +5.0VDC,
temperature compensated with a 464Ωoutput impedance.
See Figure E & F or Application Note 1 for more information.
STANDBY MODE:
The “A” 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, TTL 1, or at greater
voltages up to +32VDC the converter operates normally. The
open circuit output voltage from the Enable pin is <+5VDC. In
the inhibit mode, 1 mA will have to be sunk for proper
shutdown.
MECHANICAL:
“A” Series converters are in PCB mountable plastic cases
requiring a footprint of 5.5 in2and only 4.3 in3of volume.
Mounting plates and brackets are available for chassis
mounting. This Series is also available in an RF-tight metal
PCB/chassis mount package. 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 “A” Series provides full power operation at case
temperatures from -40 to +65oC. 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.
8 models from 0 to 62V through 0 to 6kV
4, 20, or 30 watts of output power
Maximum Iout capability down to 0 Volts
Wide input voltage range
Available with Ripple Stripper®Filter
Indefinite output short-circuit protection
Output current monitor
Fixed-frequency, low-stored-energy design
>430,000 hour MTBF @65oC
UL, CUL, IEC-60950-1, and Demko Recognized
GENERAL INFORMATION:
The “A” Series of high-voltage, regulated DC-DC
converters addresses the needs of the miniature-PCB-mount-
regulated-high-voltage-power-supply user. Designed and built
utilizing state-of-the-art power conversion topology, these
units feature surface mount technology and encapsulation
techniques providing high reliability and low cost.
DESIGN METHODOLOGY:
The “A” converters utilize a dual-ended forward converter
topology with a nominal switch frequency of <100kHz. A
precision reference is provided so the remote control can
program the power supply for a specific voltage. Once input
voltage stabilizes, under-voltage lockout is released. As soon
as enable is raised above a TTL 1, the converter begins to
switch. The soft-start circuit brings the converter to full power
over a 1mS period, reducing surges on the source supply. A
constant-frequency PWM regulation system controls the
MOSFET push-pull power stage, which drives the high voltage
transformer. The power stage is protected from output current
overloads or short circuits via a secondary current limit circuit.
High voltage is developed by a multistage multiplier while
feedback voltage is developed and sent to the CTRL circuit to
maintain regulation. Internal filters are provided to reduce
input current ripple and output voltage ripple.
WIDE INPUT RANGE:
The “A” Series is designed for full power operation at up
to 90% efficiency. A wide input range of +11 to +16VDC or +23
to +30VDC will maintain full power output without derating.
The derated input range is +9 to +32VDC. See Application
Note 16 for protection information.
WIDE OUTPUT RANGE:
The “A” Series is a non-isolated, unipolar converter.
Positive or negative output must be specified. Output voltage
is adjustable from 0 to 62, 125, 250, 500, 1kV, 2kV, 4kV, or
6kV. As the output voltage is reduced towards 0, the maximum
current capability remains unchanged.
OUTPUT CURRENT MONITOR:
The “A” Series features an output current monitor. Current
from the high-voltage multiplier can be monitored by reading
the voltage appearing between Output Monitor pin 3 and
Signal Ground Return pin 5. Internal voltage dividers create a
small linear offset voltage. See Application Note 13.
“A” SERIES
HIGH VOLTAGE POWER SUPPLY
1800 OCEAN AVE., FRNT
RONKONKOMA, NY 11779
TEL 800-9HV-POWER
FAX 631-471-4696
www.ultravolt.com
“Making High Voltage Easier!”
®9