PQ60120HZA50 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 con-
version 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 isola-
tion and voltage step-down to achieve the low output voltage
required.
Both the first stage and the second stage switch at a fixed fre-
quency 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 resis-
tance, 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 pot-
ting 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 con-
figuration.
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 ref-
erenced to the return terminal of the input bus, Vin(-). The con-
verter 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 nega-
tive logic version, the ON/OFF signal is active low (meaning that
a low voltage turns the converter on). Figure A details five possi-
ble circuits for driving the ON/OFF pin.
REMOTE SENSE(+) (Pins 7 and 5): The SENSE(+) inputs cor-
rect for voltage drops along the conductors that connect the con-
verter’s output pins to the load.
Pin 7 should be connected to Vout(+) and Pin 5 should be con-
nected 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 # PQ60120HZA50
Phone [phone]
www.synqor.com
Doc.# 005-2HZ612J Rev. A
8/20/07
Page 9