military dc-dc converter

DC-DC Converters 300W Output 12V   YN300-28S12-PEMB

Key Features

Output power: 150W RMS,300W Peak to Peak

Wide input range:22-36Vdc

High conversion efficiency: Up to 91%

Line regulation to ±1.0%

Load regulation to ±1.0%

Fixed operating frequency

Isolation voltage :1500V

Enable (ON/OFF) control

Output over-load protection

Hiccup mode short circuit protection

Over-temperature protection

Input under-voltage lock-out

Package: Open Frame

Quarter Brick: 2.32×1.49×0.45in

59×38×11.5mm

Product Overview

These DC-DC converter modules use advanced power

processing, control and packaging technologies to provide

the performance, flexibility, reliability and cost effectiveness

of a mature power component. High frequency Active Clamp

switching provides high power density with low noise and

high efficiency.

1. Electric Characteristics

Electrical characteristics apply over the full operating range of input voltage, output load and base plate temperature,unless otherwise specified. All temperatures refer to the operating temperature at the center of the base plate. All data testing at Ta=25oC except especial definition.

1.1 Absolute Maximum Ratings

1.2 Input Characteristics

1.3 Output Characteristics

1.4 Dynamic Response Characteristics

1.5 Functional Characteristics

1.6 Isolation Characteristics

2. General Characteristics

3. Environmental Characteristics

4. Standards Compliance

5. Qualification Specification

6. Typical Wave And Curves

Figure 1: Efficiency at nominal output voltage vs. load
current for minimum, nominal, and maximum input voltage
at 25°C.

Figure 2: Power dissipation at nominal output voltage vs.
load current for minimum, nominal, and maximum input
voltage at 25°C.

Figure 3: Turn-on transient at full load (resistive load) (100
ms/div).Input voltage pre-applied.
Ch 1: Vout (10V/div).Ch 2: ON/OFF input(2V/div)

Figure 4: Shut-down fall time at full load (40 ms/div).
Ch 1: Vout (10V/div).Ch 2: ON/OFF input (2V/div).

Figure 5: Output voltage response to step-change in load
current (50%-75%-50% of Iout(max); dI/dt = 0.1A/μs). Load
cap: 10μF, ≤100 mΩ ESR tantalum capacitor and0. 1μF
ceramic capacitor. Ch 1: Vout (200mV/div).

Figure 6: Output voltage response to step-change in load
current (50%-75%-50% of Iout(max): dI/dt = 2.5A/μs). Load
cap: 10μF, ≤100 mΩ ESR tantalum capacitor and 0.1μF
ceramic cap. Ch 1: Vout (200mV/div).

Figure 7: Output voltage ripple at nominal input voltage and
rated load current (100mV/div). Load capacitance:0.1μF
ceramic capacitor and 10μF tantalum capacitor. Bandwidth:
20 MHz.

7. Function Specifications

7.1 Enable (ON/OFF) Control (Pin 2)
The Enable pin allows the power module to be switched on and off electronically. The Enable (ON/OFF) function
is useful for conserving battery power, for pulsed power application or for power up sequencing.
The Enable pin is referenced to the -Vin. It is pulled up internally, so no external voltage source is required. An
open collector (or open drain) switch is recommended for the control of the Enable pin.
When using the Enable pin, make sure that the reference is really the -Vin pin, not ahead of EMI filtering or
remotely from the unit. Optically coupling the control signal and locating the opto coupler directly at the module will
avoid any of these problems. If the Enable pin is not used, it can be left floating (positive logic) or connected to the -Vin
pin (negative logic).Figure A details five possible circuits for driving the ON/OFF pin. Figure B is a detailed look ofthe internal ON/OFF circuitry.

Figure A: Various circuits for driving the ON/OFF pin.

Figure B: Internal ON/OFF pin circuitry.

7.2 Remote Sensing (Pins 7 and 5)

Remote sensing allows the converter to sense the output
voltage directly at the point of load and thus automatically
compensates the load conductor distribution & contact losses
(Figure C). There is one sense lead for each output terminal,
designated +Sense and -Sense. These leads carry very low
current compared with the load leads. Internally a resistor is
connected between sense terminal and power output terminal.
If the remote sense is not used, the sense leads needs to be
shorted to their respective output leads(Figure D).

Care has to be taken when making output connections. If
the output terminals should disconnect before the sense lines,
the full load current will flow down the sense lines and
damage the internal sensing resistors. Be sure to always power
down the converter before making any output connections.
The maximum compensation voltage for line drop is up to0.5V.

Figure C: Remote Sense Connection.

Figure D: Remote Sense is not Used.

7.3 Protection Features

·Input Under-Voltage Lockout: The converter is designed to turn off when the input voltage is too low, helping avoid
an input system instability problem, The lockout circuitry is a comparator with DC hysteresis. When the input voltage is
rising, it must exceed the typical Turn-on Voltage Threshold value(listed on the specification page) before the converter
will turn on. Once the converter is on, the input voltage must fall below the typical Turn-off Voltage Threshold value
before the converter will turn off.

·Output Current Limit: The maximum current limit remains constant as the output voltage drops. However, once the
impedance of the short across the output is small enough to make the output voltage drop below the specified Output
DC Current-Limit Shutdown Voltage, the converter into hiccup mode indefinite short circuit protection state until the
short circuit condition is removed. This prevents excessive heating of the converter or the load board.
·Over-Temperature Shutdown: A temperature sensor on the converter senses the average temperature of the module.
The thermal shutdown circuit is designed to turn the converter off when the temperature at the sensed location reaches
the Over-Temperature Shutdown value. It will allow the converter to turn on again when the temperature of the sensed
location falls by the amount of the Over-Temperature Shutdown Restart Hysteresis value.

8. Typical Application And Design Consideration

8.1 Input Filtering

DC-DC converters, by nature, generate significant levels of
both conducted and radiated noises. The conducted noises included
common mode and differential mode noises. The common mode
noise is directly related to the effective parasitic capacitance between
the power module input conductors and chassis ground. The
differential mode noise is across the input conductors. It is
recommended to have some level of EMI suppression to the power
module.
Conducted noise on the input power lines can occur as either
differential or common-mode noise currents. The required standard
for conducted emissions is EN55022 Class A (FCC Part15). (SeeFigure H).

Figure H: Input Filtering.

9. Test Method

9.1 Output Ripple & Noise Test

The output ripple is composed of fundamental frequency ripple and high frequency switching noise spikes. Thefundamental switching frequency ripple (or basic ripple) is in the 100KHz to 1MHz range; the high frequency switching
noise spike (or switching noise) is in the 10 MHz to 50MHz range. The switching noise is normally specified with 20
MHz bandwidth to include all significant harmonics for the noise spikes.
The easiest way to measure the output ripple and noise is to use an oscilloscope probe tip and ground ring pressed
directly against the power converter output pins, as shown below. This makes the shortest possible connection across
the output terminals. The oscilloscope probe ground clip should never be used in the ripple and noise measurement. The
ground clip will not only act as an antenna and pickup the radiated high frequency energy, but it will introduce the
common-mode noise to the measurement as well.
The standard test setup for ripple & noise measurements is shown in Figure I. A probe socket (Tektronix, P.N.
131.0258-00) is used for the measurements to eliminate noise pickup associated with long ground clip of scope probes.

Figure I: Ripple & Noise Standard Testing Means.

10. Physical Information

10.1 Mechanical Outline

Notes:
1. All Pins , (0.80mm) dia. (8.0mm) . stand off shoulders.
2. Tolerances: x.xx ±0.25mm. (x.x ±0.5mm)