STMicroelectronics TS831-4IZ

Overview

TS831-4IZ from STMicroelectronics is an ultra-low-power voltage supervisor IC with active-low open-drain reset output, precision 4.50 V (typ.) threshold, 100 mV hysteresis, and guaranteed operation down to 1 V supply - used for power-on reset generation in microcontroller systems requiring stable brownout detection.

For engineers reviewing the TS831-4IZ datasheet, TS831-4IZ pinout, TS831-4IZ application, or TS831-4IZ equivalent, key selection criteria include threshold accuracy over temperature, 12 µA max supply current at 5 V, fast 20 µs response under 10 mV overdrive, and TO-92 package compatibility with legacy MC33064/MC33164 designs.

Technical Context

The TS831-4IZ integrates a thermally matched band-gap reference and comparator with internal hysteresis (100 mV), enabling robust noise immunity during supply ramp-up/down. Its open-drain output requires an external pull-up and asserts low when V_CC falls below the 4.50 V threshold (V_THD = 4.40–4.66 V across –40°C to +125°C).

It operates from 1 V to 5.5 V supply, consumes only 12 µA typical current at 5 V, and delivers 8 mA sink capability at V_CC = 4 V with V_OL ≤ 1.3 V over full temperature range - making it suitable for battery-powered and low-voltage embedded systems where quiescent power and reset reliability are critical.

Key Specifications

Pinout & Package

TS831-4IZ is supplied in TO-92 plastic package (3-pin, vertical mounting), with pin 1 = V_CC, pin 2 = GND, pin 3 = RESET (open-drain output). The package meets JEDEC TO-92 mechanical standards and supports through-hole assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC33064DR2G and TPS3808G33DBVR, the TS831-4IZ uniquely combines 4.5 V precision threshold, integrated 100 mV hysteresis, TO-92 packaging, and sub-15 µA consumption - delivering plug-in reliability for legacy 5 V microcontroller reset circuits without layout changes.

Availability

TS831-4IZ is available at Aetrix Electronics and suitable for microcontroller power-on reset, industrial PLC brownout detection, and automotive body control modules requiring stable component supply with long-term manufacturability.

Supply support for TS831-4IZ 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing analog, MCU, power, and sensing solutions for automotive, industrial, and consumer markets.

The TS831 series belongs to ST's voltage supervisor product line, engineered specifically for ultra-low-power, high-accuracy reset generation in resource-constrained embedded systems - emphasizing threshold stability, wide temperature operation, and legacy pin compatibility.

FAQ

What is the recommended pull-up resistor value for the TS831-4IZ open-drain output?

For V_CC = 5 V and maximum sink current of 8 mA, a 10 kΩ pull-up yields ~0.5 V low-level output at 25°C. At –40°C, V_OL rises to ~1.3 V with same load; use 4.7 kΩ for tighter V_OL control across temperature. Graphs on page 7 of the datasheet guide selection based on ambient conditions and sink current.

Does TS831-4IZ require an external capacitor on the V_CC pin for stability?

No external bypass capacitor is required for basic operation. However, a 100 nF ceramic capacitor placed close to the V_CC and GND pins improves noise immunity during fast transients and is recommended for industrial environments per Figure 8 application schematic on page 8 of the datasheet.

Can TS831-4IZ be used with a 3.3 V microcontroller I/O rail?

Yes - its open-drain output is voltage-translating: connect the pull-up resistor to the 3.3 V I/O rail. The TS831-4IZ itself operates from 1–5.5 V, so V_CC may be 5 V while RESET pulls down a 3.3 V logic line, provided sink current stays within 8 mA limit at that V_CC.

How does the 100 mV hysteresis affect reset assertion and release voltages?

Hysteresis sets V_THD (decreasing V_CC) at ~4.40 V and V_THI (increasing V_CC) at ~4.50 V, creating a 100 mV window. This prevents oscillation during slow supply ramps or noise-induced threshold crossings - confirmed by hysteresis vs. temperature plots on page 6 of the datasheet.