bq50120qta20pys SynQor Worldwide Headquarters, bq50120qta20pys Datasheet - Page 11

• Manufacturer Part Number: bq50120qta20pys
• Description: Quarter-brick Dc Bus Converter
• Manufacturer: SynQor Worldwide Headquarters

Product # BQ50120QTA25
T
T
The number 800 is a “Load Current Scale Factor” for this prod-
uct, valid only for Vin = 48V. Hence, measurement should be
made at this input voltage.
The voltage drop across the sense resistor is about 25mV at full
load of 25A. Therefore, proper measuring techniques must be
used to ensure accuracy. A calibrated DMM set to 300mV is
acceptable. Since this measurement is done on the Primary area
of the converter, a slight non-linearity may be observed over the
load current range. Using the Scale Factor referenced above, the
error may be on the order of 4%. For more detailed information
consult the application note on SynQor’s website titled “Output
Load Current Calculations”.
Current Sharing: BusQor modules are designed to operate in
parallel without the use of any external current share circuitry. A
typical circuit for paralleling two BusQor modules is shown in
Figure H. An output capacitor is recommended across each mod-
ule and located close to the converter for optimum filtering and
noise control performance. Dedicated input inductors are rec-
ommended but are considered optional. Input capacitors must be
located close to the converter module. PCB layout in the input
circuit should be such that high frequency ripple currents of each
module is restricted to a loop formed by the input capacitors and
the input terminals of the BusQor module.
details on PCB layout. Contact SynQor application engineering
Vin
Figure G: Location of Sense Resistors
Figure H: BusQor Output Paralleling for increased current output.
echnical S
echnical S
pecification
pecification
Phone [phone]
1
2
3
1
2
3
(N logic option)
(N logic option)
BusQor module
BusQor module
See Figure K for
www.synqor.com
5
4
5
4
for further assistance on PCB trace design.
The current share performance of two paralleled modules is illus-
trated in the graph in Figure J. In this graph the percent devia-
tion from ideal sharing (50%) is plotted for each module versus
the total output load current at 48Vin.
Figure J: Current share performance of 2 paralleled modules
48Vin
Figure K: Recommended PCB layout for input circuit
12Vout
50A
10%
-2%
-4%
-6%
-8%
8%
6%
4%
2%
0%
Doc.# 005-2BQ512M Rev. C
5
CM EMI
filter
(Not shown
in Figure H)
10
15
Bulk
Cap
P
P
Total Load Current (A)
Current:
Current:
ackage:
ackage:
Output:
Output:
20
Input:
Input:
Input LC filters
25
03/17/06
42-53 V
12 V
25 A
Quarter-brick
42-53 V
12 V
25 A
Quarter-brick
30
Module 1
Module 2
35
BusQor module
BusQor module
40
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