MB3886 Fujitsu Microelectronics, Inc., MB3886 Datasheet - Page 21

• Manufacturer Part Number: MB3886
• Description: 2-channel Dc/dc Converter Ic With Overcurrent Protection Symmetrical-phase Type
• Manufacturer: Fujitsu Microelectronics, Inc.

Protection circuit
Overcurrent
protection circuit
Overvoltage
protection circuit
Short-circuit
protection circuit
Overcurrent protection
circuit
Overvoltage protection
circuit
Short-circuit protection
circuit
OUTPUT STATES DURING PROTECTION CIRCUIT OPERATION
The table below lists the output states with individual protection circuits actuated.
RESETTING THE LATCH OF EACH PROTECTION CIRCUIT
When each protection circuit (overvoltage, overcurrent, or short-circuit protection circuit) detects an abnormal
state or event, it sets the latch to fix the output at the “L” level. The PSIG1 terminal (pin 1) or PSIG2 terminal
(pin 30) is fixed at the “L” level when the overvoltage or overcurrent protection circuit detects an overvoltage or
overcurrent.
When a protection circuit operates, the latch can be released by reentering the power supply or setting the CTL1
terminal (pin 2) or CTL2 terminal (pin 29) to the “L” level.
The overvoltage and overcurrent protection circuits work for each channel separately. Use the CTL1 and CTL2
terminals to unlatch CH1 and CH2, respectively.
The short-circuit protection circuit fixes the outputs of both channels upon detection of a short circuit even on
either. Set both of the CTL1 and CTL2 terminals to the “L” level to unlatch the two channels.
: Unlatched,
Operation circuit
Output terminal
: Not unlatched
CH1
CH2
CH1
CH2
CH1
CH2
OUT1-1
Active
Active
OPEN
OPEN
OPEN
OPEN
CTL1
L
L
L
L
L
L
L
L
Unlatching Conditions
OUT2-1
Active
Active
CH1
H
L
L
L
OPEN
OPEN
OPEN
OPEN
CTL2
L
L
L
L
PSIG1
H
H
H
H
L
L
OUT1-2
Active
Active
L
L
L
L
CH1
Channels unlatched
OUT2-2
Active
Active
CH2
H
L
L
L
MB3886
CH2
PSIG2
H
H
H
H
L
L
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