The TPS1HC100-Q1 is a single-channel, fully-protected, high-side power switch with an integrated NMOS power FET and charge pump. Full diagnostics and high-accuracy current-sense features enable intelligent control of the load. Low logic high threshold, V_IH, of 1.5 V on the input pins allow use of MCU GPIO signals of 1.8 V. A programmable current-limit function greatly improves the reliability of the whole system. The device diagnostic reporting has two pins to support both digital status and analog current-sense output, both of which can be set to the high-impedance state when diagnostics are disabled, for multiplexing the MCU analog or digital interface among devices.

The digital status report is implemented with an open-drain structure on the fault pin. When a fault condition occurs, the pin is pulled down to GND. An external pullup is required to match the microcontroller supply level. High-accuracy current sensing allows a better real-time monitoring effect and more-accurate diagnostics without further calibration. A current mirror is used to source 1 / K_SNS of the load current, which is reflected as voltage on the SNS pin. K_SNS is a constant value across the temperature and supply voltage. The current-sensing function operates normally within a wide linear region from 0 to 4 V. The SNS pin can also report a fault by forcing a voltage of V_SNSFH that scales with the diagnostic enable voltage so that the maximum voltage seen by the system's ADC is within an acceptable value. This action removes the need for an external zener diode or resistor divider on the SNS pin.

The external high-accuracy current limit allows setting the current limit value by application. The current limit highly improves the reliability of the system by clamping the inrush current effectively under start-up or short-circuit conditions. Also, the current limit can save system costs by reducing PCB trace, connector size, and the preceding power-stage capacity. An internal current limit is also implemented in this device. The lower value of the external or internal current-limit value is applied.

An active drain to source voltage clamp is built in to address switching off the energy of inductive loads, such as relays, solenoids, pumps, motors, and so forth. During the inductive switching-off cycle, both the energy of the power supply (E_BAT) and the load (E_LOAD) are dissipated on the high-side power switch itself. With the benefits of process technology and excellent IC layout, the TPS1HC100-Q1 device can achieve excellent power dissipation capacity, which can help save the external free-wheeling circuitry in most cases. For more details, see Inductive-Load Switching-Off Clamp.

Short-circuit reliability is critical for smart high-side power-switch devices. The standard of AEC-Q100-012 is to determine the reliability of the devices when operating in a continuous short-circuit condition. Different grade levels are specified according to the pass cycles. This device is qualified with the highest level, Grade A, 1 million times short-to-GND certification.

The TPS1HC100-Q1 device can be used as a high-side power switch for a wide variety of resistive, inductive, and capacitive loads, including the low-wattage bulbs, LEDs, relays, solenoids, and heaters.