Input:
Output:
35-75 V
1.8 V
Current:
Package:
40 A
Quarter-brick
Technical Specification
Startup Inhibit Period: The Startup Inhibit Period ensures that
the converter will remain off for approximately 200ms when it is
shut down for any reason. When an output short is present, this
generates a 5Hz "hiccup mode," which prevents the converter
from overheating. In all, there are seven ways that the converter
can be shut down, initiating a Startup Inhibit Period:
When the input voltage rises above the UVL threshold, the Input
Under-Voltage Lockout is released, and a Startup Inhibit Period is
initiated. At the end of this delay, the ON/OFF pin is evaluated,
and since it is active, the unit turns on.
At time t1, the unit is disabled by the ON/OFF pin, and it cannot
be enabled again until the Startup Inhibit Period has elapsed.
• Input Under-Voltage Lockout
• Input Over-Voltage Shutdown (not present in Quarter-brick)
• Output Over-Voltage Protection
• Over Temperature Shutdown
• Current Limit
When the ON/OFF pin goes high after t2, the Startup Inhibit
Period has elapsed, and the output turns on within the typical
Turn-On Time.
RoHS Compliance: The EU led RoHS (Restriction of Hazardous
Substances) Directive bans the use of Lead, Cadmium,
Hexavalent Chromium, Mercury, Polybrominated Biphenyls
(PBB), and Polybrominated Diphenyl Ether (PBDE) in Electrical
and Electronic Equipment. SynQor products are currently 5/6
RoHS compliant with lead being the exception. For more infor-
mation please visit our RoHS Compliance / Lead Free Initiative
web page or e-mail us at rohs@synqor.com.
• Short Circuit Protection
• Turned off by the ON/OFF input
Figure F shows three turn-on scenarios, where a Startup Inhibit
Period is initiated at t0, t1, and t2:
Before time t0, when the input voltage is below the UVL threshold,
the unit is disabled by the Input Under-Voltage Lockout feature.
V
in
Under-Voltage
Lockout Turn-On
Threshold
ON/OFF
(pos logic)
ON
OFF
ON
OFF
ON
4ms (typical
turn on time)
V
out
200ms
(typical start-up
inhibit period)
200ms
200ms
t
t0
t1
t2
Figure F: Startup Inhibit Period (turn-on time not to scale)
Product # PQ60018QTA40
Phone 1-888-567-9596
www.synqor.com
Doc.# 005-2QT618C Rev. C
09/08/05
Page 12
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