Technical
Specification
BQ55090QTA27
36-55 V
55 V
9.6 V
Output
240 W
Max Power
2000 V dc Quarter-brick
Continuous Input Transient Input
Isolation
DC-DC Converter
The BusQor® BQ55090QTA27 bus converter is a next-
generation, board-mountable, isolated, fixed switching
frequencydc/dc converter that uses synchronous rectification
to achieve extremely high conversion efficiency. The power
dissipated by the converter is so low that a heatsink is not
required, which saves cost, weight, height, and application
effort. The BusQor series provides an isolated step down
voltage from 48V to 12 or 9.6V intermediate bus with no
regulation in a standard “quarter-brick” module. BusQor
converters are ideal for creating the mid-bus voltage required
to drive point-of-load (non-isolated) converters in intermediate
bus architectures.
Bus
Converter
Operational Features
BQ55090QTA27
Module
• High efficiency, 96 % at full rated load current at
full load
• Delivers full power with minimal derating
- no heatsink required
Control Features
• On/Off control referenced to input side
• Operating input voltage range: 36-55 V dc
• Fixed frequency switching provides predictable EMI
• No minimum load requirement
• Inherent current share (by droop method) for high
current and parallel applications.
Safety Features
Mechanical Features
• 2000 V input-to-output isolation
• UL 60950-1:2003
• CAN/CSA-C22.2 No. 60950-1:2003
• EN60950-1:2001
• Needle Flame Test (IEC 695-2-2)
• IEC 61000-4-2
• Industry standard quarter-brick pin-out configuration
(two or four output pin option)
• Size: 1.45” x 2.3” (36.8x58.4mm)
• Total height: 0.445” (11.3mm)
• Total weight: 1.5 oz (42 g)
• RoHS compliant (see page 14)
Protection Features
Contents
• Input under-voltage lockout and over-voltage
shutdown protects again abnormal input voltages
Page No.
MECHANICAL DIAGRAM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
BQ55090QTA27 ELECTRICAL CHARACTERISTICS. . . . . . . . . . . . . . . .3-4
BQ55090QTA27 Standards and Qualifications. . . . . . . . . . . . . . . . . . . . 5
BQ55090QTA27 Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-9
Application Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10-13
ORDERING INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
• Output current limit and short circuit protection
(auto recovery)
• Output over-voltage protection
• Thermal shutdown
Product # BQ55090QTA27
Phone 1-888-567-9596
www.synqor.com
Doc.# 005-2BQ559J Rev. C
04/02/09
Page 1