STMicroelectronics STM708TAM6F

Overview

STM708TAM6F from STMicroelectronics is a 3 V precision voltage supervisor IC with dual active-low and active-high reset outputs, 200 ms reset timeout, power-fail comparator (PFI/PFO), and no watchdog timer. It monitors VCC for out-of-tolerance conditions down to 1.0 V and asserts RST/RST during brownout, manual reset, or power-fail events. Used in industrial controllers and embedded systems requiring reliable power-on reset and early power-loss warning.

For engineers reviewing the STM708TAM6F datasheet, STM708TAM6F pinout, STM708TAM6F application, or STM708TAM6F equivalent, key selection criteria include its dual-reset output configuration, absence of watchdog functionality (distinguishing it from STM706T/S/R), guaranteed reset assertion down to VCC = 1.0 V, and PFI threshold of 1.25 V ±1.5% over temperature.

Technical Context

The STM708TAM6F implements independent precision comparators for VCC monitoring (VRST = 3.00–3.15 V) and power-fail detection (VPFI = 1.25 V), each driving dedicated push-pull outputs. Its reset logic guarantees RST low and RST high simultaneously when VCC falls below VRST, with trec = 200 ms (typ.) after recovery.

No internal watchdog timer is present - unlike STM706 variants - eliminating WDI/WDO pins and associated timing constraints. The MR input features an internal 40 kΩ pull-up, enabling direct switch-to-ground connection without external biasing.

Key Specifications

Pinout & Package

STM708TAM6F is housed in an 8-pin TSSOP package (3 × 3 mm body, 0.65 mm pitch), RoHS-compliant and moisture-sensitive level 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM706TAM6F, STM708TAM6F removes watchdog complexity while retaining dual-reset and PFI/PFO - ideal for cost-optimized, safety-assessed systems where firmware monitoring is handled externally. Versus TPS3808G33DBVR, it adds architectural flexibility at minimal footprint cost.

Availability

STM708TAM6F is available at Aetrix Electronics and suitable for industrial PLC controllers, medical diagnostic instruments, smart energy meters, and factory automation HMIs requiring stable component supply across extended product lifecycles.

Supply support for STM708TAM6F 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 microcontrollers, power management ICs, sensors, and analog devices for industrial, automotive, and consumer markets.

The STM70x supervisor family targets robust power-monitoring needs in resource-constrained embedded systems, emphasizing precision threshold accuracy, guaranteed low-voltage reset behavior, and integrated fault-detection features without external components.

FAQ

What is the function of the NC pin on STM708TAM6F?

Pin 8 is a no-connect (NC) terminal - internally unbonded and electrically isolated. It must remain unconnected on the PCB; routing traces to or placing solder on this pin may cause assembly defects or reliability issues. This pin exists solely for mechanical symmetry in the TSSOP8 package.

Can STM708TAM6F be used with a 3.3 V microcontroller that requires active-low reset only?

Yes - the RST pin provides a fully specified active-low reset output compatible with 3.3 V logic. RST (active-high) may be left unconnected. The device asserts RST low for ≥200 ms after VCC rises above 3.00 V, meeting standard MCU reset timing requirements without additional components.

How is the power-fail comparator calibrated, and what voltage should PFI be biased to?

The internal VPFI reference is trimmed to 1.25 V ±1.5% over temperature. To detect 3.3 V rail collapse 10 ms before failure, configure the PFI resistor divider so PFI = 1.25 V when VCC = 3.0 V - e.g., using R1 = 162 kΩ (to VCC) and R2 = 100 kΩ (to GND). PFI must not exceed VCC.

Does STM708TAM6F require external capacitors for stable operation?

A 0.1 µF ceramic decoupling capacitor between VCC and VSS, placed within 5 mm of the pins, is mandatory for noise immunity and reset timing stability. No other external capacitors are required - trec, VPFI, and VRST are internally generated and factory-trimmed.