TPS2011AD

The TPS201xA family of power distribution switches is intended for applications where heavy capacitive loads and short circuits are likely to be encountered. These devices are 50-mΩ N-channel MOSFET high-side power switches. The switch is controlled by a logic enable compatible with 5-V logic and 3-V logic. Gate drive is provided by an internal charge pump designed to control the power-switch rise times and fall times to minimize current surges during switching. The charge pump requires no external components and allows operation from supplies as low as 2.7 V. When the output load exceeds the current-limit threshold or a short is present, the TPS201xA limits the output current to a safe level by switching into a constant-current mode. 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 damage. Recovery from a thermal shutdown is automatic once the device has cooled sufficiently. Internal circuitry ensures the switch remains off until valid input voltage is present. The TPS201xA devices differ only in short-circuit current threshold. The TPS2010A limits at 0.3-A load, the TPS2011 at 0.9-A load, the TPS2012A at 1.5-A load, and the TPS2013A at 2.2-A load. The TPS201xA is available in an 8-pin small-outline integrated-circuit (SOIC) package and in a 14-pin thin-shrink small-outline package (TSSOP) and operates over a junction temperature range of -40°C to 125°C. The power switch is an N-channel MOSFET with a maximum on-state resistance of 50 mΩ (VIN = 5V). Configured as a high-side switch, the power switch prevents current flow from OUT to IN and IN to OUT when disabled. An internal charge pump supplies power to the driver circuit and provides the necessary voltage to pull the gate of the MOSFET above the source. The charge pump operates from input voltages as low as 2.7 V and requires very little supply current. The driver controls the gate voltage of the power switch. To limit large current surges and reduce the associated electromagnetic interference (EMI) produced, the driver incorporates circuitry that controls the rise times and fall times of the output voltage. The rise and fall times are typically in the 2-ms to 9-ms range. The logic enable disables the power switch, the bias for the charge pump, driver, and other circuitry to reduce the supply current to less than 10 μA when a logic high is present on EN. A logic zero input on EN restores bias to the drive and control circuits and turns the power on. The enable input is compatible with both TTL and CMOS logic levels. A sense FET monitors the current supplied to the load. The sense FET measures current more efficiently than conventional resistance methods. When an overload or short circuit is encountered, the current-sense circuitry sends a control signal to the driver. The driver, in turn, reduces the gate voltage and drives the power FET into its saturation region, which switches the output into a constant current mode and holds the current constant while varying the voltage on the load. An internal thermal-sense circuit shuts off the power switch when the junction temperature rises to approximately 140°C. Hysteresis is built into the thermal sense circuit. After the device has cooled approximately 20°C, the switch turns back on. The switch continues to cycle off and on until the fault is removed. A voltage sense circuit monitors the input voltage. When the input voltage is below approximately 2 V, a control signal turns off the power switch.

Key features

• 33-mΩ(5-V Input) High-Side MOSFET Switch
• Short-Circuit and Thermal Protection
• Operating Range: 2.7 V to 5.5 V Logic-Level Enable Input
• Typical Rise Time: 6.1 ms
• Undervoltage Lockout
• Maximum Standby Supply Current: 10 μA
• No Drain-Source Back-Gate Diode
• Available in 8-pin SOIC and 14-Pin TSSOP Packages
• Ambient Temperature Range: -40°C to 85°C
• 2-kV Human-Body-Model, 200-V Machine-Model ESD Protection