TPS1H100-Q1
www.ti.com.cn
ZHCSDD8D –OCTOBER 2014–REVISED DECEMBER 2019
7 Detailed Description
7.1 Overview
The TPS1H100-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. A programmable current-limit function greatly improves the reliability of the whole system. The device
diagnostic reporting has two versions 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.
For version A, the digital status report is implemented with an open-drain structure. When a fault condition
occurs, it pulls down to GND. A 3.3- or 5-V external pullup is required to match the microcontroller supply level.
For version B, 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 of the load current, which is
reflected as voltage on the CS pin. K 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 CS pin can also report a fault
by pulling up the voltage of VCS,h
.
The external high-accuracy current limit allows setting the current limit value by application. It highly improves the
reliability of the system by clamping the inrush current effectively under start-up or short-circuit conditions. Also, it
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 and 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 (EBAT) and the load (ELOAD) are dissipated on the high-side power switch itself. With the benefits of
process technology and excellent IC layout, the TPS1H100-Q1 device can achieve excellent power dissipation
capacity, which can help save the external free-wheeling circuitry in most cases. See Inductive-Load Switching-
Off Clamp for more details.
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 TPS1H100-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.
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