PQ60120HZX50 Datasheet, PDF (9/13 Pages) SynQor Worldwide Headquarters – Half-brick DC/DC Converter

Technical Specification
Input: 35-75 V
Output: 12 V
Current: 50 A (600W)
Package: Half-brick
BASIC OPERATION AND FEATURES
The PowerQor Zeta series converter uses a two-stage power
conversion topology. The first stage keeps the output voltage
constant over variations in line, load, and temperature. The
second stage uses a transformer to provide the functions of
input/output isolation and voltage step-down to achieve the low
output voltage required.
Both the first stage and the second stage switch at a fixed
frequency for predictable EMI performance. Rectification of
the transformer’s output is accomplished with synchronous
rectifiers. These devices, which are MOSFETs with a very low
on-state resistance, dissipate significantly less energy than
Schottky diodes, enabling the PowerQor converter to achieve
high efficiency.
Dissipation throughout the converter is so low that it does not
require a heatsink for operation. Since a heatsink is not required,
the PowerQor converter does not need a metal baseplate or
potting material to help conduct the dissipated energy to the
heatsink. As an open frame module, the PowerQor converter can
be built more simply and reliably using high yield surface mount
techniques on a PCB substrate.
The PowerQor series of half-brick, quarter-brick and eighth-brick
converters uses the industry standard footprint and pin-out
configuration.
ON/OFF
ON/OFF
ON/OFF
Vin(_)
Remote Enable Circuit
Vin(_)
Negative Logic
(Permanently Enabled)
Vin(_)
Positive Logic
(Permanently Enabled)
ON/OFF
5V
CMOS
ON/OFF
Vin(_)
Open Collector Enable Circuit
Vin(_)
Direct Logic Drive
Figure A: Various circuits for driving the ON/OFF pin.
CONTROL FEATURES
REMOTE ON/OFF (Pin 2): The ON/OFF input, Pin 2, permits
the user to control when the converter is on or off. This input is
referenced to the return terminal of the input bus, Vin(-). The
converter is available with either positive or negative logic used
for the ON/OFF input.
In the positive logic version, the ON/OFF input is active high
(meaning that a high voltage turns the converter on). In the
negative logic version, the ON/OFF signal is active low (meaning
that a low voltage turns the converter on). Figure A details five
possible circuits for driving the ON/OFF pin.
REMOTE SENSE(+) (Pins 7 and 5): The SENSE(+) inputs
correct for voltage drops along the conductors that connect the
converter’s output pins to the load.
Pin 7 should be connected to Vout(+) and Pin 5 should be
connected to Vout(-) at the point on the board where regulation
is desired. If these connections are not made, the converter will
deliver an output voltage that is slightly higher than its specified
value.
Note: The output over-voltage protection circuit senses the
voltage across the sense leads (pins 7 and 5) to determine when
it should trigger, not the voltage across the converter’s output
pins (pins 8 and 4).
OUTPUT VOLTAGE TRIM (Pin 6): The TRIM input permits the
user to adjust the output voltage across the sense leads up or
down according to the trim range specifications. SynQor uses
industry standard trim equations.
To decrease the output voltage, the user should connect a
resistor between Pin 6 (TRIM) and Pin 5 (SENSE(–) input). For
a desired decrease of the nominal output voltage, the value of
the resistor should be:
( ) ^Rtrim-down ⁼
100%
D
_2
kW
where
^{D% =}
Vnominal – Vdesired
Vnominal
x 100%
Product # PQ60120HZx50
Phone [phone]
www.synqor.com
Doc.# 005-2HZ612J Rev. D
06/12/09
Page 9