The MAX4881–MAX4884 overvoltage protection (OVP)
controllers with built-in current-limited switch, protect low voltage
systems against voltages of up to 28V. When the
input voltage exceeds the overvoltage trip level of 5.6V
(MAX4881/MAX4883) or 4.5V (MAX4882/MAX4884), the
external n-channel MOSFET is turned off to prevent damage
to the protected components. An undervoltage/overvoltage
flag indicator (OV-bar) notifies the processor that an
undervoltage/overvoltage fault condition is present.
The MAX4881/MAX4882 feature an internal 1.1A current-limited switch, while the MAX4883B/MAX4883C/MAX4884B/MAX4884C include an internal 0.7A current-limited
switch. When the load current is at the current
limit for longer than the blanking time, the switch of the
MAX4881/MAX4882/MAX4883B/MAX4884B latches off
and does not turn back on until Active-Low EN, CB, or IN is cycled.
A current-limit flag (Active-Low FLAGI) asserts to indicate a current
fault condition.
The MAX4883C/MAX4884C limit the current to 0.7A
indefinitely until the thermal protection trips. An overcurrent
flag output asserts to indicate a current fault condition
after the blanking time has elapsed.
The MAX4881–MAX4884 have a control input (CB) that
is used to turn on and off the internal current-limited
switch. Other features include a shutdown function (Active-Low EN)
to disable the external n-channel MOSFET, and a built-in
startup delay to allow the adapter voltage to settle
down before turning on the MOSFET.
The MAX4881–MAX4884 is offered in a space-saving
10-pin TDFN package and is specified for operation
over the extended -40°C to +85°C temperature range.
Applications
- Cell Phones
- Digital Still Cameras
- MP3 Players
- PDAs and Palmtop Devices
