65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with 碌P Reset and Watchdog Timer
EN and
HOLD.
Figure 3 shows the timing diagram for the
enable and hold functions. Connecting
HOLD
to OUT or
floating
HOLD
allows the EN input to act as a standard
ON/OFF switch for the regulator output.
load conditions. Thermal protection protects the
MAX5023/MAX5024 in the event of fault conditions. For
continuous operation, do not exceed the absolute maxi-
mum junction temperature rating of T
J
= +150擄C.
MAX5023/MAX5024
Thermal Protection
When the junction temperature exceeds T
J
= +150擄C, an
internal thermal sensor signals the shutdown logic that
turns off the pass transistor and allows the IC to cool.
The thermal sensor turns the pass transistor on again
after the IC鈥檚 junction temperature cools by 20擄C, result-
ing in a cycled output during continuous thermal-over-
V
IN
Applications Information
Output Voltage Selection (MAX5024 only)
The MAX5024 features Dual Mode
鈩?/div>
operation: it oper-
ates in either a preset voltage mode or an adjustable
mode. In preset voltage mode, internal trimmed feed-
back resistors set the MAX5024鈥檚 internal linear
regulator to +3.3V or +5V (see the
Selector Guide).
V
EN
V
EN, ON
V
EN, OFF
1)
5)
>10碌s
V
HOLD
>10碌s
V
HOLD, REL
2)
V
HOLD, HOLD
4)
6)
7)
V
OUT
V
TH
8)
V
OUT (NOM)
V
RESET
200ms
3)
0.2V
9)
1) ENABLE ACTIVE
2) HOLD INACTIVE, PULLED UP BY V
OUT
3) POWER-ON RESET
4) HOLD ACTIVE, CLAMPED TO GND BY EXTERNAL
碌P
5) ENABLE INACTIVE, CLAMPED BY INT, PULLDOWN RESISTOR
6) PULSE WIDTH SMALLER THAN 10碌s
7) HOLD INACTIVE, RELEASED BY
碌P
8) REGULATOR OUTPUT SHUTDOWN
9) OUTPUT-LOW RESET
Figure 3. Enable and Hold Behavior
Dual Mode is a trademark of Maxim Integrated Products, Inc.
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