Texas Instruments TPS3421EGDRYR

Overview

TPS3421EGDRYR from Texas Instruments is a dual-input, low-power push-button reset controller with fixed 400-ms active-low open-drain reset pulse, operating from 1.6 V to 6.5 V supply and supporting –40°C to +125°C ambient. It monitors PB1 and PB2 simultaneously, asserts RST only after both inputs are held low ≥7.5 s (TS = GND), and deasserts RST after the fixed 400-ms pulse-enabling reliable hard-reset differentiation in portable power management systems.

For engineers reviewing the TPS3421EGDRYR datasheet, TPS3421EGDRYR pinout, TPS3421EGDRYR application, or TPS3421EGDRYR equivalent, key selection criteria include its dual-push-button timing logic, factory-programmed 400-ms tRST, ultra-low 250-nA standby current at 3.3 V, USON-6 (1.45 mm × 1.00 mm) package, and compatibility with system-level reset coordination in space-constrained consumer electronics.

Technical Context

The TPS3421EGDRYR implements a two-stage digital timing architecture: first, a configurable push-button timer (tTIMER = 7.5 s when TS = GND) validates simultaneous low states on PB1 and PB2; second, a dedicated reset pulse generator produces a precise, temperature-stable 400-ms RST low pulse independent of input release timing. Its NMOS-based input structure requires external pullups, and the open-drain RST output supports wire-OR with other reset sources.

This device operates in three functional modes: normal operation above 1.6 V (with full timing spec compliance), sub-threshold operation between 1.3 V–1.6 V (input-responsive but out-of-spec), and power-on reset below 1.3 V (high-impedance RST). The TS pin selects tTIMER options but must remain static during operation-only sampled at power-up or when PBx is high.

Key Specifications

Pinout & Package

TPS3421EGDRYR is housed in a 6-pin USON (DRY) package measuring 1.45 mm × 1.00 mm × 0.5 mm, optimized for ultra-dense PCB layouts in smartphones and wearables.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar push-button reset controller applications.

Compared with TPS3420EGDRYR, TPS3421EGDRYR delivers guaranteed 400-ms reset assertion independent of input release-critical for deterministic boot reliability. Against MAX6369KA+T, it adds dual-input validation and cuts standby current by >90%, enabling longer battery life in safety-aware portable systems.

Availability

TPS3421EGDRYR is available at Aetrix Electronics and suitable for smartphone power sequencing, industrial HMI reset interfaces, portable medical monitors, and gaming handheld recovery requiring stable component supply, long-lifecycle support, and AEC-Q200-aligned reliability.

Supply support for TPS3421EGDRYR 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 delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and personal electronics markets.

The TPS342x product line was designed specifically for ultra-low-power, space-constrained push-button reset coordination-addressing demand for reliable, battery-friendly hard-reset functionality in next-generation portable and safety-critical systems.

FAQ

What is the exact reset pulse duration of the TPS3421EGDRYR?

The TPS3421EGDRYR provides a factory-programmed fixed reset pulse duration (tRST) of 400 ms typical, with guaranteed range of 320 ms to 480 ms across –40°C to +125°C and 1.6 V–6.5 V supply. This value is independent of PB1/PB2 release timing and remains stable over temperature and voltage-ensuring consistent microprocessor power-on reset behavior in the TPS3421EGDRYR.

How does the TS pin configure timing on the TPS3421EGDRYR?

On the TPS3421EGDRYR, the TS pin selects between two push-button timer (tTIMER) options: tying TS to GND sets tTIMER = 7.5 s typical, while TS = VCC configures tTIMER = 0 s (intended only for factory test). The TS state is sampled at power-up or when PBx is high-so it must remain statically connected and cannot be toggled during normal operation of the TPS3421EGDRYR.

Does the TPS3421EGDRYR require external pullup resistors on PB1 and PB2?

Yes, the TPS3421EGDRYR requires external pullup resistors on both PB1 and PB2 pins because it uses NMOS-based threshold inputs. These resistors ensure defined high states when buttons are open and enable proper detection of simultaneous low transitions. Typical values range from 10 kΩ to 100 kΩ, selected based on system noise immunity and leakage tolerance-critical for reliable operation of the TPS3421EGDRYR.

What is the minimum supply voltage for guaranteed operation of the TPS3421EGDRYR?

The TPS3421EGDRYR guarantees full specification compliance-including timing accuracy and input thresholds-down to 1.6 V supply (VCC). Below 1.6 V but above 1.3 V, the device remains functional but electrical characteristics are not assured. Below 1.3 V, RST enters high-impedance mode, though this state is not guaranteed across all conditions-making 1.6 V the practical minimum for robust design with the TPS3421EGDRYR.

Can the TPS3421EGDRYR output drive a 3.3-V logic rail directly?

Yes, the TPS3421EGDRYR's open-drain RST output can drive a 3.3-V logic rail directly: its VOL is specified at ≤0.3 V with 5-mA sink current at VCC ≥3.3 V, and it supports pullup to any voltage up to 6.5 V-regardless of its own VCC level. A 10-kΩ pullup to 3.3 V ensures fast rise time and compatible logic levels, making the TPS3421EGDRYR interoperable with standard CMOS inputs.