MAX1516 Datasheet, PDF (18/26 Pages) Maxim Integrated Products – TFT-LCD DC-DC Converters with Operational Amplifiers

TFT-LCD DC-DC Converters with
Operational Amplifiers
IN
5µA
DEL
REF
MAX1516
MAX1517
MAX1518
2.5V
FB OK
FBP OK
FBN OK
SRC
Q1
COM
CTL
1kΩ
Q2
Q3
DRN
Figure 7. Switch-Control Block
Fault Protection
During steady-state operation, if the output of the main
regulator or any of the linear-regulator outputs does not
exceed its respective fault-detection threshold, the
MAX1516/MAX1517/MAX1518 activate an internal fault
timer. If any condition or combination of conditions indi-
cates a continuous fault for the fault-timer duration
(55ms typ), the MAX1516/MAX1517/MAX1518 set the
fault latch to shut down all the outputs except the refer-
ence. Once the fault condition is removed, cycle the
input voltage (below the UVLO falling threshold) to
clear the fault latch and reactivate the device. The fault-
detection circuit is disabled during the soft-start time.
Thermal-Overload Protection
Thermal-overload protection prevents excessive power
dissipation from overheating the MAX1516/MAX1517/
MAX1518. When the junction temperature exceeds T_J =
+160°C, a thermal sensor immediately activates the
fault protection, which shuts down all outputs except
the reference, allowing the device to cool down. Once
the device cools down by approximately 15°C, cycle
the input voltage (below the UVLO falling threshold) to
clear the fault latch and reactivate the device.
The thermal-overload protection protects the controller
in the event of fault conditions. For continuous opera-
tion, do not exceed the absolute maximum junction
temperature rating of T_J = +150°C.
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