MAX14562 Datasheet, PDF (8/10 Pages) Maxim Integrated Products – 36V-Capable Overvoltage Protector with Regulated Output Voltage

36V-Capable Overvoltage Protector with
Regulated Output Voltage
Functional Diagram
Q1
IN
OUT
PROV CONTROL
OVLO CONTROL
HV CP
PROTECTION
BG
POK
MAX14562
INOVLO
VBG
TIMING
AND
CONTROL LOGIC
EN
OK
ACOK
EN
Detailed Description
The MAX14562 features the overvoltage protection to
the charger input VBUS line when a travel adapter (TA) is
used. In addition, the MAX14562 features a low 160mI
(typ) on-resistance internal FET (Q1) and protects the
low-voltage system against voltage faults up to +36V.
The MAX14562 features three-step overvoltage pro-
tection. When the input is below the preset regulated
output-voltage (VPROV) threshold, the output follows
the input minus the voltage drop across the pass FET
(RON x ILOAD). When the input exceeds VPROV, the
output is regulated to VPROV. If the input rises further
and exceeds the overvoltage lockout cutoff (VOVLO)
threshold, the output is disconnected from the input. The
MAX14562 also features thermal shutdown protection
against short-circuit events.
Soft-Start
To minimize inrush current, the MAX14562 features a
soft-start capability to slowly turn on Q1.
Soft-start function permits the device to charge the load
capacitor up to 1000FF by controlled current. The soft-
start is initiated when the debounce time ends (OUT
starts charging) and ends when ACOK is asserted low,
15ms (typ).
Linear Mode
When the input voltage exceeds the minimum IN volt-
age but is below VPROV, OUT follows IN with a minimum
voltage drop (RON x ILOAD) across pass FET after the
debounce time, tDEB, and ACOK is asserted.
The LDO mode needs a capacitor on OUT. The recom-
mended value is 10FF for load currents up to 800mA
(Table 1).
Preset Regulated Output-Voltage Mode
(PROV)
When IN goes above the preset regulated output voltage
(VPROV), Q1 provides a constant voltage of VPROV at
OUT, and ACOK is asserted.
Table 1. Recommended Load Capacitance
LOAD CURRENT (mA)
10
50
100
800
LOAD CAP (µF)
1
2.2
4.7
10
8