TI TPS2041PE4

The TPS2041 and TPS2051 power distribution switches are intended for applications where heavy capacitive loads and short circuits are likely to be encountered. The TPS2041 and the TPS2051 are 135-mΩ N-channel MOSFET high-side power switches. Each switch is controlled by a logic enable compatible with 5-V and 3-V logic. Gate drive is provided by an internal charge pump that controls 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 TPS2041 and TPS2051 limit the output current to a safe level by switching into a constant-current mode, pulling the overcurrent (OC) logic output low. 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 in overcurrent 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 TPS2041 and TPS2051 are designed to limit at 0.9-A load. These power distribution switches are available in 8-pin small-outline integrated circuit (SOIC) and 8-pin plastic dual-in-line packages (PDIP) and operate over an ambient temperature range of -40°C to 85°C. The power switch is an N-channel MOSFET with a maximum on-state resistance of 135 mΩ (V_I(IN)=5 V). Configured as a high-side switch, the power switch prevents current flow from OUT to IN and IN to OUT when disabled. The power switch supplies a minimum of 500 mA per switch. 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 4-ms range. The logic enable disables the power switch and 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 (TPS2041) or a logic low is present on EN (TPS2051). A logic zero input on EN or a logic high 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. The OC open drain output is asserted (active low) when an overcurrent or overtemperature condition is encountered. The output will remain asserted until the overcurrent or overtemperature condition is removed. 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.

• 135-mΩ -Maximum (5-V Input) High-Side MOSFET Switch
• 500 mA Continuous Current
• Short-Circuit and Thermal Protection With Overcurrent Logic Output
• Operating Range: 2.7 V to 5.5 V
• Logic-Level Enable Input
• 2.5-ms Typical Rise Time
• Undervoltage Lockout
• 10 μA Maximum Standby Supply Current
• Bidirectional Switch
• Available in 8-pin SOIC and PDIP Packages
• Ambient Temperature Range: -40°C to 85°C
• 2-kV Human-Body-Model, 200-V Machine-Model ESD Protection
• UL Listed – File No. E169910