ACE345E

Adjustable USB Load Current Switch

VER 1.2

5

Function Description

The ACE345E is a load switch which provides full protection to systems and loads which may encounter

large current conditions. ACE345E offers a

95mΩ current-limited switch which can operate over an input

voltage range of 2.5-5.5V. The current limit can be externally programmed by a precision resistor, ranges

from 75mA to 1.7A. ACE345E also features reverse voltage blocking, UVLO, and thermal shutdown to

protect IC from overheating.

Current Limiting

The current limit ensures that the current through the switch doesn't exceed a maximum value while not

limiting at less than a minimum value. The current at which the parts will limit is adjustable through the

selection of an external resistor connected to ILIM. Information for selecting the resistor is found in the

Application Info section. ACE345E thermal cycles if an overload condition is present long enough to

activate thermal limiting in any of the above cases. The device turns off when the junction temperature

exceeds 135°C (t y p) while in current limit. The device remains off until the junction temperature cools

10°C (t y p) and then restarts

Reverse-Voltage Blocking

The reverse-voltage protection feature turns off the Power MOSFET whenever the output voltage

exceeds the input voltage by 150mV (typ) for 4-ms (typ). This prevents damage to devices on the input

side of the ACE345E by preventing significant current from sinking into the input capacitance. The

ACE345E allow the power MOSFET to turn on once the output voltage goes below the input voltage for

the same 4-ms deglitch time.