©2006 Bel Fuse Inc. Specifications subject to change without notice. 11.06

POWER PRODUCTS

GMDW12V08

Bel Power Inc. 155 Flanders Road, Westborough, MA 01581 • Tel 508-870-9775 • Fax 508-870-9796 • www.belpower.com

DORADO MV DC/DC CONVERTERS

48V Input – 12VDC – 8A Output

page 4

Application Notes

Bel Power’s Proprietary CoolConverter™

•

Patented single-stage power conversion architecture,

control and magnetic design allow unprecedented

power density and efficiency in an isolated power

supply.

Protection and Control

Valid Input Voltage Range

The converter measures the input voltage and will not allow

operation outside of the input voltage specification. As

shown by the graphs, hysteresis is added to both the high

and low voltage to prevent the converter from turning on and

off repeatedly when the voltage is held near either voltage

extreme. At low line, this assures the maximum input current

is not exceeded; at high line, this assures the semiconductor

devices in the converter are not damaged by excessive

voltage stress.

ON/OFF Logic Option

The ON/OFF control logic can be either Negative (standard)

or Positive to enable the converter. For Negative logic, the

ON/OFF pin is brought to below 1.0V with respect to the

–INPUT pin to enable the converter. The pull-down must be

able to sink 100µA. For Positive logic, the ON/OFF pin is

brought to greater than 4.0V with respect to the –INPUT pin

and be limited to less than 10V. To request the Positive logic

version, add the suffix (P) to the standard part number. The

ON/OFF pin has a built-in pull-up resistor of approximately

100k

Ω to +5V.

Output Over Voltage Protection

The output voltage is constantly monitored by the

microprocessor with a redundant secondary-side

measurement circuit that both shuts down the duty cycle and

triggers the microprocessor to shut down. If the output voltage

exceeds the over voltage specification, the microprocessor

will latch the converter off. To turn the converter on required

either cycling the ON/OFF pin or power to the converter. This

advanced feature prevents the converter from damaging the

load if there is a converter failure or application error. If non-

latching is required, consult factory.

•

An advanced microcontroller reduces parts count while

adding features, performance and flexibility in the design.

Under Voltage Hysteresis

1.0

0

30

34

37

Input Voltage (V)

36

32

33

35

31

Over Voltage Hysteresis

1.0

0

76.5

78.5

80.5

Input Voltage (V)

79.5

77.5

78

80

79

77