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STMicroelectronics STM806TM6E
- Part No.:
- STM806TM6E
- Manufacturer:
- STMicroelectronics
- Category:
- Supervisors
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
STM806TM6E.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8SO
- Quantity:
- Payment:
- Shipping:
Inventory:1,075
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Product details
Overview
STM806TM6E from STMicroelectronics is a 3 V industrial-grade microprocessor supervisory IC with manual reset input, automatic battery switchover, power-fail comparator (PFI/PFO), and guaranteed RST assertion down to VCC = 1.0 V. It provides push-pull active-low RST output, operates from –40 °C to +85 °C, draws only 40 µA typical supply current, and supports external LPSRAM backup via VOUT/VBAT switching.
For engineers reviewing the STM806TM6E datasheet, STM806TM6E pinout, STM806TM6E application, or STM806TM6E equivalent, this device is selected for reliable power monitoring in battery-backed embedded systems where deterministic reset timing, low quiescent current, and seamless VCC-to-VBAT transition are critical - especially in metering, industrial controllers, and data loggers requiring nonvolatile SRAM retention during main power loss.
Technical Context
The STM806 implements a precision voltage comparator monitoring VCC against a 2.63 V reset threshold (VRST) with hysteresis, asserting RST for ≥200 ms (trec) after VCC recovery or MR release. Its PFI/PFO circuit detects falling VCC below 2.4 V (VSW) or PFI < VPFI (1.25 V), generating early power-fail warning with push-pull PFO output.
No watchdog timer or chip enable gating is present - distinguishing it from STM804/805/795 variants. The MR input features an internal 40 kΩ pull-up and accepts TTL/CMOS logic levels; RST remains valid even at VCC = 1.0 V when VBAT > 1 V, enabling robust reset behavior during brownout conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold (VRST) | 2.63 V ±1.5% - guarantees RST assertion before MCU fails; stable over temperature and supply noise. |
| Reset Timeout (trec) | 200 ms (typ) - ensures sufficient hold time for full system initialization after power recovery. |
| Supply Current (ICC) | 40 µA (typ) - enables long-term operation in battery-backed applications without significant drain. |
| Battery Current (IBAT) | 0.4 µA (typ) - minimizes backup battery depletion during extended VCC outage. |
| Power-Fail Threshold (VPFI) | 1.25 V - triggers PFO low before VCC drops below critical MCU operating voltage. |
| VCC Switchover Voltage (VSW) | 2.4 V - initiates automatic VOUT connection to VBAT before system reset occurs. |
| Operating Temperature | –40 °C to +85 °C - qualified for industrial environments including factory automation and outdoor metering. |
Pinout & Package
STM806TM6E is housed in an 8-pin SO8 (Small Outline Integrated Circuit) package, 3.9 mm × 4.9 mm body, 1.27 mm pitch, RoHS-compliant lead-free finish.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1: PFO | Power-fail output | Push-pull active-low signal indicating imminent VCC failure; drives interrupt or NMI line directly. |
| 2: VOUT | Supply output for LPSRAM | Switched output connected to VCC above 2.4 V, or to VBAT below 2.4 V; supplies up to 75 mA to external SRAM. |
| 3: VCC | Main supply input | Primary 3 V system rail; monitored for reset and switchover; requires local 0.1 µF decoupling. |
| 4: RST | Active-low reset output | Push-pull output asserted low during VCC undervoltage, MR activation, or power-up; compatible with standard MCU reset inputs. |
| 5: VSS | Ground reference | System ground return; must be low-impedance path shared with MCU and LPSRAM. |
| 6: MR | Manual reset input | Active-low input with internal 40 kΩ pull-up; debounced internally - no external RC needed for push-button use. |
| 7: PFI | Power-fail input | Monitors auxiliary rail or scaled VCC; asserts PFO when voltage falls below 1.25 V; connect to GND if unused. |
| 8: VBAT | Backup battery input | Accepts 1.8–5.5 V backup source; automatically powers VOUT when VCC drops below 2.4 V; connect to VCC if no battery used. |
Key Features
| Feature | Design Value |
|---|---|
| Guaranteed RST assertion down to VCC = 1.0 V | Ensures reset remains active through deep brownout, preventing MCU lockup even with weak or sagging 3 V rail. |
| Automatic battery switchover at 2.4 V | Transfers LPSRAM supply to VBAT before reset triggers, preserving memory contents without software intervention. |
| Low 40 µA supply current | Reduces system-level power budget impact - critical for always-on industrial sensors and battery-operated edge devices. |
| Integrated PFI/PFO comparator | Provides early power-fail warning (1.25 V threshold) with push-pull output, eliminating need for external comparator and pull-up. |
| MR with internal 40 kΩ pull-up | Enables direct push-button connection without external components; supports noise immunity via optional 0.1 µF capacitor to GND. |
Applications
| Smart Electricity Meter | Industrial PLC Controller |
|---|---|
|
Use Scenario: Maintains real-time energy accumulation and tariff data in external LPSRAM during grid brownouts or scheduled power cycling. IC Role / Device Role / Timing Role: Supervisory IC providing VCC monitoring, battery-backed VOUT switchover, and hard reset to MCU upon undervoltage. Use Value: Prevents data corruption by ensuring SRAM remains powered and MCU resets cleanly - meeting IEC 62053-21 data integrity requirements. |
Use Scenario: Ensures deterministic restart of control logic after unexpected AC line interruption in factory-floor automation cabinets. IC Role / Device Role / Timing Role: Reset supervisor with manual reset (MR) and power-fail warning (PFO) feeding PLC safety watchdog and HMI interrupt lines. Use Value: Enables fail-safe state recovery within 200 ms, satisfying IEC 61131-2 response time constraints for safety-critical motion control. |
| Remote Data Logger | Building Energy Management System (BEMS) |
|
Use Scenario: Preserves sensor calibration tables and timestamped measurements in LPSRAM during multi-day battery-only operation after mains failure. IC Role / Device Role / Timing Role: Battery switchover controller and reset generator, with ultra-low 0.4 µA battery drain during backup mode. Use Value: Extends usable backup runtime by >30% versus higher-quiescent alternatives, supporting 5+ year field deployments without battery replacement. |
Use Scenario: Monitors HVAC controller power rails and triggers graceful shutdown of fan actuators and valve drivers prior to complete AC loss. IC Role / Device Role / Timing Role: Power-fail detector (PFI/PFO) and reset coordinator interfacing with ARM Cortex-M4 host and analog front-end. Use Value: Avoids mechanical stress on dampers/valves by initiating controlled ramp-down using PFO interrupt, reducing maintenance frequency. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX809SEUR+T | Single VRESET = 2.93 V; no PFI/PFO, no MR, no battery switchover; SOT-23-3 package. | Limited to basic reset-only use cases; cannot support LPSRAM backup or early power-fail warning. | Select only when minimal footprint and cost are prioritized over battery management and fault prediction. |
| TPS3808G12DBVR | Adjustable reset threshold (1.22–5.5 V); 350 ms tREC; no battery switchover; includes watchdog timer. | Requires external resistor divider for threshold setting; lacks integrated VOUT/VBAT switching for SRAM. | Choose when programmable reset voltage and watchdog supervision are required, but battery backup is handled separately. |
Compared with MAX809SEUR+T and TPS3808G12DBVR, STM806TM6E uniquely integrates battery switchover, PFI/PFO, and MR in an SO8 package - delivering complete power supervision for LPSRAM-based systems without additional discrete components or layout area.
Availability
STM806TM6E is available at Aetrix Electronics and suitable for smart metering, industrial PLCs, remote data loggers, and building energy management systems requiring stable component supply across extended product lifecycles.
Supply support for STM806TM6E 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 chips for industrial, automotive, and consumer markets.
The STM690/704/806 family was engineered specifically for robust power supervision in battery-backed embedded systems - emphasizing low quiescent current, guaranteed reset behavior under brownout, and seamless VCC-to-VBAT transition for nonvolatile memory retention.
FAQ
What is the function of the Vccsw pin on STM806TM6E?
Vccsw is a push-pull output that goes high when VOUT switches to VBAT (indicating main power loss) and low when VOUT reconnects to VCC. It is designed to drive the gate of an external PMOS transistor to extend VOUT current capability beyond the internal 75 mA limit - essential for powering larger LPSRAM arrays or peripheral circuits during backup mode.
Does STM806TM6E include a watchdog timer?
No. Unlike STM804/805/802 variants, STM806TM6E does not incorporate a watchdog timer - as confirmed in Section 2.3 of the datasheet ("Watchdog input (NOT available on STM704/795/806)"). Its supervision relies solely on VCC monitoring, manual reset (MR), and power-fail detection (PFI/PFO).
Can VBAT exceed VCC on STM806TM6E?
Yes. The datasheet explicitly states "VBAT may exceed VCC" in Section 1.1.11. The internal P-channel MOSFET switch isolates VCC and VBAT paths, allowing safe operation with higher-voltage backup sources (e.g., 3.6 V Li-ion) while VCC remains at 3.0 V - enabling flexible battery chemistry selection without level-shifting circuitry.
How is the reset timeout (trec) determined, and is it adjustable?
trec is fixed at 200 ms (typical) and internally generated - no external components or configuration pins affect its duration. This value is guaranteed across temperature and supply voltage per Table 7 (DC and AC characteristics), ensuring consistent reset hold time for reliable MCU initialization regardless of board-level variations or environmental conditions.
STM806TM6E Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Type:
- Simple Reset/Power-On Reset
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 3.075V
- Output:
- Push-Pull, Totem Pole
- Reset:
- Active Low
- Reset Timeout:
- 140ms Minimum
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
STM806TM6E FAQ
1.How can I place an order for STM806TM6E through Aetrix?
Please submit a Request for Quotation (RFQ) for STM806TM6E on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for STM806TM6E reliable?
The price and inventory of STM806TM6E are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STM806TM6E is usually 5 days.
3.What payment methods are accepted for STM806TM6E?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STM806TM6E transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STM806TM6E?
STM806TM6E orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STM806TM6E order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for STM806TM6E?
For technical support, including STM806TM6E datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STM806TM6E requirements.
6.How does Aetrix verify that STM806TM6E is sourced from the original manufacturer or authorized distributors?
All STM806TM6E products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that STM806TM6E meets industry standards.
7.What is the process for return or replacement of STM806TM6E?
All STM806TM6E units undergo pre-shipment inspection (PSI). If there is an issue with STM806TM6E, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The STM806TM6E part is unused and in its original packaging.
Return procedure for STM806TM6E:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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