ST204x and ST205x Series
CURRENT LIMITED POWER DISTRIBUTION SWITCHES

ST2042 Product Page ST2044 Product Page ST2052 Product Page ST2054 Product Page ST2042, ST2044, ST2052 and ST2054 power switches are mainly intended for all USB applications where heavy capacitive loads and hort circuits are likely to be encountered. These devices incorporate 80mΩ N-Channel MOSFET high-side power switches for power-distribution systems that require multiple power switches in a single package.

ST2042 and ST2052 contain two low resistance switches while ST2044 and ST2054 contain four. The functionality of each switch is controlled by an independent logic enable input. When the output load exceeds the current-limit threshold or a short circuit is present, the output current is limited to a safe level by switching into a constant-current mode and the overcurrent logic output pin switches to a low state. When continuous heavy overloads and short circuits increase the power dissipation in the switch, causing the junction temperature to rise, a thermal protection circuit shuts off the switch to prevent possible damage. Recovery from a thermal shutdown is automatic once the device has cooled sufficiently. Internal circuitry ensures the switch remains off until a valid input voltage is present. These power-distribution switches are designed to limit currents at 0.9A.

80mΩ high-side MOSFET switch;
500mA continuous current per channel;
Independent thermal and short circuit protection;
Overcurrent logic output flag;
Operating range from 2.7V to 5.5V;
CMOS and TTL compatible enable inputs;
2.5ms typical rise time;
Undervoltage lockout;
10µA maximum standby supply current.

Thermal Sense Protecion Reference

ST204x and ST205x implement a dual-threshold thermal trip in order to allow fully independent operation of the power distribution switches. When the die temperature rises to approximately 140C, the internal thermal sense circuitry checks which power switch is in an overcurrent condition and turns the switch off, thus isolating the fault without interrupting operation of the adjacent power switch. An open-drain output is asserted (active low) when overtemperature or overcurrent occurs.

Package

These power distribution switches are available in
the 8 and 16-pin small-outline SO-8 and SO-16
packages and operate over an ambient temperature
range of –40C to 85C.