FA5527 FUJI [Fuji Electric], FA5527 Datasheet - Page 30

• Manufacturer Part Number: FA5527
• Description: Fuji Switching Power Control IC
• Manufacturer: FUJI [Fuji Electric]

(9) Over Temperature Protection as latch mode
(10) Prevention of malfunction caused by
(11) Gate circuit configuration
achieved by the circuit shown in Fig.39 for FA5526/27/28.
pin, because the start-up time of IC may become too long
when the circuit including a thermistor is connected to VCC
pin of IC directly.
used for FA5536/37/38, because FA5536/37/38 does not
include any latch function.
parasitic element in the IC may operate and cause a
malfunction. Be sure that voltage applied to a pin shall not
be -0.3V or less.
may be applied to the OUT pin via the parasitic
capacitance of the MOSFET, resulting in the negative
voltage applied to the OUT pin.
pin and GND. Forward voltage of the Shottky diode can
suppress negative voltage at each pin. Use a Shottky
diode with low forward voltage.
diode connected to the OUT pin.
terminal of the MOSFET and the OUT pin of the IC for
adjustment of switching speed, suppression of voltage
oscillation at the gate terminal and other purposes.
must independently determined.
MOSFET and OUT pin of the IC as shown in Fig.41 or
Fig.42.
turn-on and by only Rg2 at turn-off
AN-087E Rev.1.0
April-2011
for FA5526 / 27 / 28
turn-on and by parallel-connected Rg1 and Rg2 at
turn-off.
negative voltage applied to pins
Over Temperature Protection as latch mode can be
Here, a diode D1 connected to separated line from VCC
Please note that the circuit shown in Fig. 39 can not be
When a large negative voltage is applied to a pin, a
Voltage oscillation generated at turn-off of the MOSFET
In such a case, connect a Shottky diode between each
Fig.40 shows an example of a circuit with a Shottky
A resistor is generally inserted between the gate
Sometimes, the drive currents for turning-on and -off
In such a case, connect the gate terminal of the
In Fig.41, the driving current is limited by Rg1 + Rg2 at
In Fig.42 the driving current is limited by only RG1 at
Fuji Electric Co., Ltd.
FA5526/5527/5528/5536/5537/5538
30
Fig. 39 Over Temperature Protection
Fig.40 Negative voltage prevention circuit
Note : OTP Latch by FA5536 / 5537 / 5538 can not
be achieved by above circuit. FA5536 / 5537
/ 5538 may need very complicated circuit for
OTP latch.
by Latch Mode for FA5526 / 5527 /5528
Fig.41 Gate circuit (1)
Fig.42 Gate circuit (2)
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