Texas Instruments TPS3897ADRYR

Overview

TPS3897ADRYR from Texas Instruments is a single-channel, adjustable-voltage supervisor IC with open-drain output, designed for precise power-rail monitoring in space-constrained systems. It features a 500 mV fixed threshold (±1% over –40°C to 125°C), capacitor-adjustable reset delay (40 µs to 190 ms), 6 µA typical quiescent current, and operates from 1.7 V to 6.5 V supply. It is used to assert reset signals to microcontrollers and FPGAs during brownout or startup conditions.

For engineers reviewing the TPS3897ADRYR datasheet, TPS3897ADRYR pinout, TPS3897ADRYR application, or TPS3897ADRYR equivalent, key selection criteria include its ultra-small USON-6 (1.45 mm × 1.00 mm) package, open-drain SENSE_OUT rated to 18 V, active-high ENABLE input, and capacitor-programmable delay timing - all critical for low-power, high-density embedded power sequencing.

Technical Context

The TPS3897ADRYR implements a precision comparator with 500 mV reference and 5 mV hysteresis to detect voltage excursions on the SENSE pin. Its CT pin integrates a 310 nA current source that charges an external capacitor to set the assertion delay, enabling programmable reset timeout from 40 µs (CT open) up to 190 ms (47 nF).

It uses an active-high ENABLE input to gate output assertion independently of SENSE status; when ENABLE is low, SENSE_OUT is immediately forced low regardless of SENSE voltage. The open-drain output supports level-shifting up to 18 V and wired-OR configurations, making it suitable for mixed-voltage system reset buses.

Key Specifications

Pinout & Package

TPS3897ADRYR is housed in a 6-pin USON (Ultra-Small Outline No-lead) package measuring 1.45 mm × 1.00 mm × 0.5 mm, optimized for PCB area savings in portable and high-density designs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage supervisor applications.

Compared with TPS3897ADRYR, TPS3897PDRYR trades programmable delay for faster enable response, while MAX6897ASA+T sacrifices flexibility (no ENABLE, fixed delay) for drop-in replacement simplicity in legacy SOT-23 layouts - TPS3897ADRYR uniquely balances adjustability, size, and interface control.

Availability

TPS3897ADRYR is available at Aetrix Electronics and suitable for microcontroller power sequencing, FPGA configuration monitoring, battery-powered sensor nodes, industrial PLC power supervision, and portable computing requiring stable component supply across extended temperature and voltage ranges.

Supply support for TPS3897ADRYR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and power management technologies, with decades of expertise in high-reliability supervisory circuits and precision voltage references.

The TPS389x family was developed to address demand for ultra-compact, low-power voltage supervisors in space-constrained applications such as wearables, IoT edge nodes, and automotive ADAS modules - emphasizing programmability, wide supply range, and robust thermal performance.

FAQ

What is the minimum supply voltage required for TPS3897ADRYR to operate correctly?

The TPS3897ADRYR requires a minimum supply voltage of 1.7 V to guarantee proper functionality, including accurate threshold detection and output assertion. Below 1.7 V, the device enters undervoltage lockout (UVLO) and deasserts SENSE_OUT; operation below the power-on reset voltage of 0.8 V renders output behavior undefined. This ensures reliable reset generation only when VCC is within specification.

How does the CT pin on TPS3897ADRYR determine the reset delay time?

The CT pin on TPS3897ADRYR connects to an internal 310 nA current source that charges an external capacitor to 1.24 V; the resulting time defines the SENSE_OUT assertion delay. Delay is calculated as t_pd(r) = [C_CT(µF) × 4] + 40 µs - e.g., a 22 nF capacitor yields ~128 µs delay. Leaving CT open gives a fixed 40 µs delay. Ceramic capacitors are recommended to minimize leakage error.

Can TPS3897ADRYR monitor a 5 V rail directly, or is a resistor divider required?

TPS3897ADRYR cannot monitor a 5 V rail directly because its SENSE pin maximum rating is 6.5 V, but its internal comparator threshold is fixed at 0.5 V. A resistor divider is required to scale the 5 V rail down to ≤0.5 V at the SENSE pin - for example, R1 = 90 kΩ and R2 = 10 kΩ yields 0.5 V at SENSE when VIN = 5 V, satisfying the 500 mV threshold condition.

What is the purpose of the ENABLE pin on TPS3897ADRYR, and how does it interact with SENSE?

The ENABLE pin on TPS3897ADRYR is an active-high control input that gates SENSE_OUT assertion: when ENABLE is low, SENSE_OUT is immediately forced low regardless of SENSE voltage; when ENABLE is high and SENSE exceeds 0.5 V, SENSE_OUT asserts after the CT-programmed delay. This enables software-controlled reset initiation or power sequencing coordination independent of rail voltage status.

Is TPS3897ADRYR compatible with 18 V logic systems despite its 6.5 V VCC rating?

Yes - TPS3897ADRYR's SENSE_OUT is an open-drain output rated for 18 V, meaning it can be pulled up to 18 V using an external resistor, even when VCC is as low as 1.7 V. This allows direct interfacing with higher-voltage logic families or legacy reset buses without level shifters, while VCC solely powers the internal supervisor circuitry.