STMicroelectronics STM813LM6E

Overview

STM813LM6E from STMicroelectronics is a 5 V precision voltage supervisor IC with active-high reset output, watchdog timer, manual reset input (MR), and power-fail comparator (PFI/PFO). It asserts RST when VCC drops below 4.50–4.75 V, provides 200 ms reset timeout (trec), and guarantees RST assertion down to VCC = 1.0 V. Used in industrial microcontroller systems for reliable power-on reset and brownout protection.

For engineers reviewing the STM813LM6E datasheet, STM813LM6E pinout, STM813LM6E application, or STM813LM6E equivalent, key selection criteria include reset threshold accuracy (±1.5% over temperature), guaranteed operation down to 1.0 V VCC, push-pull RST/RST outputs, 1.6 s watchdog timeout, and compatibility with noisy environments via MR internal pull-up and optional debounce capacitor.

Technical Context

The STM813LM6E integrates a precision bandgap reference, dual comparators (VCC monitor and PFI threshold), a 1.6 s watchdog timer with WDI edge-sensitive clearing, and independent push-pull RST (active-low) and RST (active-high) outputs. Its reset logic ensures trec ≥ 200 ms after VCC recovery or MR release, with propagation delay < 30 µs across –40 °C to 85 °C.

It features a dedicated power-fail comparator (VPFI = 1.25 V ±2%) decoupled from the VCC monitor, enabling early warning of supply collapse before VCC reaches VRST. The MR input includes an internal 40 kΩ pull-up resistor and supports TTL/CMOS logic levels or mechanical switch interfaces without external components.

Key Specifications

Pinout & Package

STM813LM6E is housed in an 8-pin TSSOP package (3 mm × 3 mm body, 0.65 mm pitch), optimized for space-constrained PCB layouts while maintaining thermal and electrical performance comparable to SOIC-8.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX813L, STM813LM6E offers tighter VRST tolerance (±1.5% vs ±2.5%) and guaranteed 1.0 V operation, enhancing reliability in noisy or aging power supplies; versus TPS3808G33, it delivers full integration (watchdog, dual reset, PFI/PFO) without external components but lacks threshold adjustability.

Availability

STM813LM6E is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive body control modules, medical infusion pumps, and smart energy meters requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for STM813LM6E 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, Switzerland, designing and manufacturing analog, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

The STM813L series belongs to ST's precision voltage supervisor product line, engineered specifically for robust power monitoring in safety-critical embedded systems where deterministic reset behavior and long-term reliability are mandatory.

FAQ

Can STM813LM6E operate with a 3.3 V supply?

No. STM813LM6E is specified only for 4.50 V to 5.5 V operation. Its internal voltage reference and comparators are trimmed for 5 V systems; applying 3.3 V will prevent proper reset assertion and may cause undefined output states. For 3.3 V rails, consider ST's STM3408 or TPS3808G18.

How is the watchdog timer disabled?

The watchdog timer is disabled by leaving the WDI pin floating or tri-stated. Internal leakage current must remain below 10 µA, and load capacitance must not exceed 200 pF. No external pull-up/down is required - the timer stops counting and does not assert WDO or trigger reset.

What is the purpose of the dual RST and RST outputs?

RST is active-low and RST is active-high - both driven simultaneously and synchronously. This eliminates the need for external inverters when interfacing with MCUs that require opposite reset polarities, such as legacy 8051 derivatives (active-low) alongside newer ARM Cortex-M parts (active-high).

Does PFO require a pull-up resistor?

No. PFO is a push-pull output with integrated driver transistors, capable of sinking or sourcing current up to 20 mA. It drives high or low actively without external components. Connecting a pull-up resistor would create contention and is unnecessary per the datasheet design.