Input:

230-400 V

Output:

13.6 V

Current:

45 A

Package:

EXTENDED Eighth-brick

Product # BQ4H136EEC45

Phone 1-888-567-9596

www.synqor.com

Doc.#005-0006641 Rev. C

05/11/16

Page 10

Input:

230-400 V

Output:

13.6 V

Current:

45 A

Package:

EXTENDED Eighth-brick

Applications Section

Output

Current

Output

Voltage

0V

Time

Time

Output

Current

Output

Voltage

0V

PROTECTION FEATURES

Input Under-Voltage Lockout: The converter is designed

to turn off when the input voltage is too low, helping avoid

an input system instability problem, described in more detail

in the application note titled “Input System Instability”. The

lockout circuitry is a comparator with DC hysteresis. When

the input voltage is rising, it must exceed the typical Turn-

On Voltage Threshold value (listed on the specification

page) before the converter will turn on. Once the converter

is on, the input voltage must fall below the typical Turn-Off

Voltage Threshold value before the converter will turn off.

Also see Figure E.

Input Over-Voltage Shutdown: The converter also has

a two stage over-voltage feature that limits the converter's

duty cycle for 100 ms before shutdown and a higher second

level with no delay before shutdown if the input voltage

is too high (See the Input Over-Voltage Shutdown section

in the Electrical Characteristics Table for specific voltage

levels). It also has a hysteresis and time delay to ensure

proper operation.

Output Current Limit: The output of the BusQor module

is electronically protected against output overloads. When

an overload current greater than the “DC Current-Limit

Inception” specification is drawn from the output, the output

shuts down to zero volt in a period of 1 ms typical (see

Figure C). The shutdown period lasts for a typical period of

250 ms (Figure D) after which the BusQor tries to power up

again (10 ms). If the overload persists, the output voltage

will go through repeated cycles of shutdown and restart

with a duty cycle of 4% (On) and 96% (Off) respectively.

The BusQor module returns (auto resetting) to normal

operation once the overload is removed. The BusQor is

designed to survive in this mode indefinitely without damage

and without human intervention.

Output Short Circuit Protection: When the output of

the BusQor module is shorted, a peak current of typically

70 A will flow into the short circuit for a period not greater

than 1 ms (typically 200 uS). The output of the BusQor will

shutdown to zero for ~ 250 mS (Figure D). At the end of

the shutdown period the BusQor module tries to power up

again. If the short circuit persists, the output voltage will

go through repeated cycles of shutdown and restart with

a duty cycle of 4% (On) and 96% (Off) respectively. The

BusQor module returns (auto resetting) to normal operation

once the short circuit is removed. The BusQor is designed

to survive in this mode indefinitely without damage and

without human intervention.

In the Auto resetting mode, also referred to as “Hiccup”

mode, the power drawn from the 385 V input is about ~10

Watts, most of which is dissipated into the external fault. It

is important that copper traces and pads from the output

circuit be designed to withstand the short term peaks,

although the average current into the fault may be as low

as 0.04 A typical. See Figure 17 for appropriate waveform.

Over-Temperature Shutdown: A temperature sensor

on the converter senses the average temperature of the

module. The thermal shutdown circuit is designed to turn the

converter off when the temperature at the sensed location

reaches the Over-Temperature Shutdown value. It will allow

the converter to turn on again when the temperature of the

sensed location falls by the amount of the Over-Temperature

Shutdown Restart Hysteresis value.

Figure C: Output Overload protection diagram (not to scale)

55 A

45 A

13.6 V

1 ms

Figure D: Output Short Circuit and Auto-Resetting protection diagram (not to

scale)

70 A

peak

<13 V

250 ms

10 ms