Specifications

TPS1H100-Q1

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SLVSCM2A –OCTOBER 2014–REVISED JANUARY 2014

8 Detailed Description

8.1 Overview

The TPS1H100-Q1 is a high-side power switch that is fully protected and single channel, with integrated NMOS

power FET and charge pump. Full diagnostics and high-accuracy current sense features enable intelligent

control of the load. Programmable current limit function greatly improves the whole system’s reliability. The

device diagnostic reporting has two versions to support both digital status and analog current sense output, both

of which can be set as high impedance 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

happens, it pulls down to GND. 3.3- or 5-V external pullup is required to match the microcontroller’s supply level.

For version B, high-accuracy current sensing allows 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. Wide linear

region from 0 to 4 V is presented for normal operation current sensing function. The CS pin can also report a

fault with pulled up voltage of V

CS,h

The external high-accuracy current limit allows setting the current limit value by application. It highly improves the

system’s reliability 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. Internal

current limit is also implemented in this device. The smaller 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 energy of inductive load, including

the 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, TPS1H100-Q1 can achieve excellent power dissipation

capacity, which can help save the external free-wheeling circuitry in most cases. Refer to 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.

TPS1H100-Q1 can be used as a high-side power switch a wide variety of resistive, inductive, and capacitive

loads, including the low-wattage bulbs, LEDs, relays, solenoids, and heaters.

Product Folder Links: TPS1H100-Q1