PQ60120QZB33 Datasheet, PDF (9/13 Pages) SynQor Worldwide Headquarters – Protection from permanent damage and hazardous conditions

Applications Section
Technical
Specification
PQ60120QZB33
BASIC OPERATION AND FEATURES
CONTROL FEATURES
This converter series 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
converter to achieve high efficiency.
Dissipation throughout the converter is so low that it does not
require a heatsink for operation in many applications; however,
adding a heatsink provides improved thermal derating performance
in extreme situations. To further withstand harsh environments
and thermally demanding applications, certain models are available
baseplated or totally encased. See Ordering Information page for
available thermal design options.
SynQor quarter-brick converters use the industry standard footprint
and pin-out.
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(-).
In negative logic versions, the ON/OFF signal is active low (meaning
that a low voltage turns the converter on). In positive logic versions,
the ON/OFF input is active high (meaning that a high voltage turns
the converter on). Fig A details possible circuits for driving the ON/
OFF pin. See Ordering Information page for available enable logics.
REMOTE SENSE Pins 7(+) and 5(-): The SENSE(+) and
SENSE(-) inputs correct for voltage drops along the conductors that
connect the converter’s output pins to the load.
Pin 7 should connect to Vout(+) and Pin 5 should connect 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 output (pins 8 and 4) to determine when it should trigger,
not the voltage across the converter’s sense leads (pins 7 and 5).
Therefore, the resistive drop on the board should be small enough
so that output OVP does not trigger, even during load transients.
ON/OFF
ON/OFF
ON/OFF
Vin(^_)
Vin(^_)
Remote Enable Circuit
Negative Logic
(Permanently
Enabled)
ON/OFF
5V
Vin(^_)
Positive Logic
(Permanently
Enabled)
TTL/
CMOS
ON/OFF
Vin(^_)
Open Collector Enable Circuit
Vin(^_)
Direct Logic Drive
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:
where
( ) Rtrim-down =
511%
Δ%
– 10.22
kΩ
| | ^{Vnominal – Vdesired}
Δ% =
Vnominal
× 100%
To increase the output voltage, the user should connect a resistor
between Pin 6 (TRIM) and Pin 7 (SENSE(+) input). For a desired
increase of the nominal output voltage, the value of the resistor
should be:
Figure A: Various Circuits for Driving the ON/OFF Pin.
[ ^{( )} ] ^{Rtrim-up = 5.11}
Vnominal
1.225 ^{– 2 × Vdesired + Vnominal} _kΩ
Vdesired – Vnominal
Product # PQ60120QZB33
Phone [phone]
The Trim Graph in Figure B shows the relationship between the
trim resistor value and Rtrim-up and Rtrim-down, showing the total
range the output voltage can be trimmed up or down.
Note: The TRIM feature does not affect the voltage at which the
output over-voltage protection circuit is triggered. Trimming the
output voltage too high may cause the over-voltage protection
circuit to engage, particularly during transients.
www.synqor.com
Doc.# 005-0005586 Rev. G
02/04/15
Page 9