See Product Details

•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 @65°C

•UL, CUL, DEMKO, and IEC-60950-1 Recognized

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 VOLTAGE 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.

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 464Ω output 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 in² and only 4.3 in³ of 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 +65°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.