FAN2110 Fairchild Semiconductor, FAN2110 Datasheet - Page 13

• Manufacturer Part Number: FAN2110
• Description: This part is covered in Fairchild's href="http://www
• Manufacturer: Fairchild Semiconductor

© 2008 Fairchild Semiconductor Corporation
FAN2110 • Rev. 1.0.3
The OV/UV fault protection circuits above are active all
the time, including during soft-start.
Over-Temperature Protection (OTP)
The chip incorporates an over-temperature protection
circuit that sets the fault latch when a die temperature of
about 150°C is reached. The IC restarts when the die
temperature falls below 125°C.
Auto-Restart
After a fault, EN pin is discharged by a 1µA current sink
to a 1.1V threshold before the internal 800K pull-up is
restored. A new soft-start cycle begins when EN
charges above 1.35V.
Depending on the external circuit, the FAN2110 can be
configured to remain latched-off or to automatically
restart after a fault.
Table 1. Fault / Restart Configurations
EN Pin
Pull to GND
Pull-up to V
Open
Cap. to GND
CC
with 100K
Controller / Restart State
OFF (Disabled)
No Restart – Latched OFF
(After V
Immediate Restart After Fault
New Soft-Start Cycle After:
t
DELAY
(ms)=3.9 • C(nf)
CC
Comes Up)
13
When EN is left open, restart is immediate.
If auto-restart is not desired, tie the EN pin to the VCC
pin or pull it HIGH after V
to keep the 1µA current sink from discharging EN to
1.1V. Figure 32 shows one method to pull up EN to V
for a latch configuration.
Power-Good (PGOOD) Signal
PGOOD is an open-drain output that asserts LOW when
V
Thresholds are specified in the Electrical Specifications
section. PGOOD does not assert HIGH until the fault
latch is enabled (T1.0) (see Figure 31).
OUT
Figure 32.
is out of regulation, as measured at the FB pin.
Enable Control with Latch Option
CC
comes up with a logic gate
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CC