TI TPS2010D

The TPS201x series power distribution switches are designed for applications that may encounter large capacitive loads and short circuits. The high-side switch is a 95-mΩ N-channel MOSFET. Gate drive is provided by an internal driver and charge pump designed to control the rise and fall times of the power switch, reducing current surges during switching. The charge pump operates at 100 kHz, requires no external components, and allows supply voltages as low as 2.7 V. When the output load exceeds the current limit threshold or a short circuit occurs, the TPS201x limits the output current to a safe level by switching to constant-current mode. Sustained heavy overloads and short circuits increase power dissipation in the switch, causing junction temperature to rise. If the junction temperature reaches approximately 180°C, the thermal protection circuit shuts down the switch to prevent damage. Once the device has cooled sufficiently, thermal shutdown recovery is automatic.

Members of the TPS201x family differ only in their short-circuit current threshold. The TPS2010 is designed to current-limit at a 0.4 A load; other members of the family current-limit at 1.2 A, 2 A, and 2.6 A respectively (see the available options table). The TPS201x family is available in 8-pin SOIC and 14-pin TSSOP packages, with an operating junction temperature range of -40°C to 125°C. The 8-pin SOIC version is a drop-in replacement for the Siliconix Littlefoot power PMOS switch, but GND must be connected.

The power switch is an N-channel MOSFET configured as a high-side switch, with a maximum on-resistance of 95 mΩ (V_I(IN) = 5.5 V).

An internal 100 kHz charge pump powers the drive circuitry and provides the voltage necessary to pull the MOSFET gate above its source. The charge pump operates at input voltages as low as 2.7 V and draws very little supply current.

The driver controls the gate voltage of the power switch. To limit large current surges and reduce associated EMI, the driver incorporates circuitry that controls the rise and fall times of the output voltage. Rise and fall times are typically in the 2 ms to 4 ms range, rather than the microsecond or nanosecond range of a standard FET.

A logic high on the EN input shuts down the power switch along with the bias for the charge pump, driver, and other circuitry, reducing supply current to less than 10 μA. A logic-low input restores bias to the drive and control circuitry and turns on the power. The enable input is compatible with TTL and CMOS logic levels.

A sense FET monitors the current delivered to the load. The sense FET measures current more efficiently than conventional resistor-based methods. When an overload or short circuit is detected, the current sense circuit sends a control signal to the driver. The driver then reduces the gate voltage, driving the power FET into its linear region, switching the output to constant-current mode, and maintaining constant current while the load voltage varies.

The internal thermal detection circuit shuts down the power switch when the junction temperature rises to approximately 180°C. The thermal detection incorporates hysteresis; the switch turns back on after the device cools by approximately 20°C. The switch continues to cycle on and off until the fault is removed.

When correctly assembled, the die exhibits characteristics similar to the TPS201xC. Thermocompression or ultrasonic bonding may be used on the aluminum-doped bond pads. The die can be mounted using conductive epoxy or gold-silicon preforms.

• 95mΩ max (5.5V input) high-side MOSFET switch with logic-compatible enable input
• Short-circuit and thermal protection
• Typical short-circuit current limit: 0.4A for TPS2010; 1.2A for TPS2011; 2A for TPS2012; 2.6A for TPS2013
• ESD protection: 12kV on output, 6kV on all other terminals
• Controlled rise and fall times to limit inrush current and minimize EMI
• SOIC-8 pinout compatible with popular Littlefoot series when GND connected
• 2.7V to 5.5V operating range
• 10µA max standby current
• Surface-mount SOIC-8 and TSSOP-14 packages
• -40°C to 125°C operating junction temperature range