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STMicroelectronics STM802SM6E
- Part No.:
- STM802SM6E
- Manufacturer:
- STMicroelectronics
- Category:
- Supervisors
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
STM802SM6E.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8SO
- Quantity:
- Payment:
- Shipping:
Inventory:3,925
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Product details
Overview
STM802SM6E from STMicroelectronics is a 3 V industrial-grade microprocessor supervisory IC with battery switchover, active-low push-pull RST output, manual reset (MR), watchdog timer (1.6 s typ), and power-fail comparator (PFI/PFO). It guarantees RST assertion down to VCC = 1.0 V and supports non-volatile SRAM backup via VOUT switching between VCC and VBAT. Used in embedded controllers requiring reliable power monitoring and brownout recovery.
For engineers reviewing the STM802SM6E datasheet, STM802SM6E pinout, STM802SM6E application, or STM802SM6E equivalent, key selection criteria include guaranteed reset assertion at 1.0 V VCC, 200 ms typical reset timeout (trec), 0.4 µA typical battery supply current, push-pull RST drive capability, and integrated PFI/PFO for early power-fail warning in battery-backed systems.
Technical Context
The STM802 implements a precision voltage reference and comparator to monitor VCC against a fixed reset threshold (VRST ≈ 2.63 V), asserting RST when VCC falls below VRST or during MR activation. Its internal trec generator ensures minimum 200 ms reset pulse width after power-up or fault recovery.
A dedicated watchdog timer monitors WDI transitions; absence of edge activity for ≥1.6 s triggers reset. The device also integrates automatic battery switchover logic that connects VBAT to VOUT when VCC drops below 2.4 V (VSW), with Vccsw providing a push-pull indicator signal for external PMOS control.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold (VRST) | 2.63 V ±1.5% - Ensures deterministic MCU reset initiation before critical logic voltage collapse |
| Reset Timeout (trec) | 200 ms (typ) - Guarantees sufficient hold time for full microprocessor initialization sequence |
| Watchdog Timeout (tWD) | 1.6 s (typ) - Provides robust detection window for stalled firmware without false triggering |
| Battery Supply Current | 0.4 µA (typ) - Enables multi-year operation on coin-cell backup without significant drain |
| Power-Fail Threshold (VPFI) | 1.25 V (typ) - Triggers PFO assertion early enough to save critical data before VCC dropout |
| Operating Temperature | –40 °C to +85 °C - Validated for industrial environments including factory automation and metering |
| VCC Switchover Voltage (VSW) | 2.4 V - Defines precise transition point for seamless VOUT sourcing from VBAT during main supply failure |
Pinout & Package
STM802SM6E is housed in an 8-pin SO8 (Small Outline) package per JEDEC MS-012, with 1.27 mm pitch and surface-mount footprint. Pin 1 is marked by a beveled corner or dot.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| PFO | Power-fail output | Push-pull active-low signal indicating imminent VCC failure; drives interrupt or save-state logic |
| PFI | Power-fail input | Monitors auxiliary rail or scaled VCC to trigger PFO assertion before main supply collapse |
| WDI | Watchdog input | Edge-sensitive input requiring periodic toggling; resets internal timer on rising/falling edges |
| RST | Active-low reset output | Push-pull output asserted low during VCC undervoltage, MR activation, or watchdog timeout |
| VCC | Main supply input | Primary 3 V system rail; powers internal circuitry and sources VOUT until switchover threshold |
| VOUT | SRAM supply output | Switched output connected to VCC or VBAT; supplies external LPSRAM during main power loss |
| VBAT | Backup battery input | Accepts 1.0–5.5 V backup source; automatically engages when VCC falls below 2.4 V |
| VSS | Ground reference | Common return path for all analog and digital functions; must be low-impedance connection |
Key Features
| Feature | Design Value |
|---|---|
| Guaranteed RST assertion down to VCC = 1.0 V | Ensures reset remains valid even during deep brownout, preventing MCU latch-up or undefined state |
| Automatic battery switchover with Vccsw indicator | Vccsw provides clean push-pull logic-level signal to enable external high-current PMOS switch for >75 mA VOUT loads |
| Integrated power-fail comparator (PFI/PFO) | Delivers early warning (≥100 µs response) before VCC dropout, enabling last-chance data save to NVRAM |
| Manual reset with internal 40 kΩ pull-up | Eliminates need for external resistor; supports direct switch-to-ground or logic-level MR assertion |
| Low 40 µA typical supply current (VCC mode) | Minimizes impact on primary 3 V rail in always-on monitoring applications such as smart sensors |
Applications
| Industrial PLC Controller | Smart Electricity Meter |
|---|---|
Use Scenario: Continuous operation in unattended factory-floor controllers where unexpected power dips must not corrupt program state or I/O configuration. IC Role / Device Role / Timing Role: Supervisory IC providing brownout reset, watchdog supervision, and battery-backed SRAM retention during AC line sag. Use Value: Prevents firmware crash and preserves real-time clock and calibration data using <2.4 V switchover and 0.4 µA battery drain. |
Use Scenario: Utility-grade meter requiring tamper-proof energy logging across grid outages lasting minutes to hours. IC Role / Device Role / Timing Role: Power-fail detector and SRAM supervisor ensuring EEPROM writes complete before VCC collapse. Use Value: PFI/PFO comparator triggers immediate data flush at 1.25 V, while VOUT maintains 3 V SRAM supply from coin cell for >10 years shelf life. |
| Medical Infusion Pump | Point-of-Sale Terminal |
Use Scenario: Life-critical infusion device needing fail-safe shutdown and audit trail preservation during battery swap or mains interruption. IC Role / Device Role / Timing Role: Dual-role supervisor: asserts hardware reset on VCC anomaly and gates SRAM write-enable during power transition. Use Value: 200 ms trec ensures pump motor controller fully halts before memory save; RST guaranteed to 1.0 V prevents partial execution. |
Use Scenario: Retail terminal with flash-based firmware and transaction log buffer requiring atomic commit on power loss. IC Role / Device Role / Timing Role: System-level power integrity manager coordinating PFO-triggered log flush and RST-hold for safe reboot. Use Value: 1.6 s watchdog enforces firmware liveness check; Vccsw signal enables external load switch to isolate backup rail during normal operation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX809TRD3 | Single VCC reset only; no watchdog, no PFI/PFO, no battery switchover | Suitable only for basic reset generation-lacks STM802SM6E's SRAM backup and power-fail warning | Select when cost-sensitive designs require only reset assertion without supervision features |
| TPS3808G33DBVR | Adjustable reset threshold (via external resistor); no battery switchover or PFI input | Supports custom VCC monitoring but cannot replace VOUT/VBAT switching function | Choose for flexible threshold tuning in non-battery-backed systems where precision reset level matters |
Compared with MAX809TRD3 and TPS3808G33DBVR, STM802SM6E uniquely integrates battery switchover, watchdog, and power-fail detection in one SO8 package-enabling compact, self-contained SRAM backup without external logic or discrete switches.
Availability
STM802SM6E is available at Aetrix Electronics and suitable for industrial PLC controllers, smart electricity meters, medical infusion pumps, and point-of-sale terminals requiring stable component supply across extended product lifecycles.
Supply support for STM802SM6E 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 silicon solutions for automotive, industrial, and consumer markets since 1987.
The STM690/704/795/802/804/805/806 family was engineered specifically for robust microprocessor supervision in battery-backed embedded systems-emphasizing low-power operation, precise voltage monitoring, and seamless power-source handover.
FAQ
What is the guaranteed minimum VCC level at which RST remains asserted?
STM802SM6E guarantees RST assertion down to VCC = 1.0 V when VBAT > 1 V, and also guarantees valid RST down to VCC = 1.0 V without battery backup. This ensures reliable reset signaling during deep brownout conditions common in industrial power environments.
Does STM802SM6E support both active-high and active-low reset outputs?
No-STM802SM6E provides only an active-low push-pull RST output. The active-high open-drain RST variant is found in STM804/805 models. STM802SM6E's RST pin is strictly active-low and does not require an external pull-up resistor due to its push-pull driver.
Can the watchdog timer be disabled?
No-the watchdog timer cannot be disabled. Leaving WDI floating, tied high, or tied low causes automatic reset every ~1.8 s (tWD + trec). To prevent spurious resets, the host MCU must toggle WDI at least once every 1.6 s with edges ≥50 ns wide.
How does VOUT behave when no battery is connected?
When no battery is used, VBAT and VOUT must both be connected to VCC. In this configuration, VOUT remains tied to VCC at all times, and the internal switchover MOSFET remains off. The device operates as a standard supervisor without backup functionality, consuming only 40 µA typical supply current.
STM802SM6E 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:
- 2.925V
- 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
STM802SM6E FAQ
1.How can I place an order for STM802SM6E through Aetrix?
Please submit a Request for Quotation (RFQ) for STM802SM6E 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 STM802SM6E reliable?
The price and inventory of STM802SM6E are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STM802SM6E is usually 5 days.
3.What payment methods are accepted for STM802SM6E?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STM802SM6E transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STM802SM6E?
STM802SM6E orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STM802SM6E 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 STM802SM6E?
For technical support, including STM802SM6E datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STM802SM6E requirements.
6.How does Aetrix verify that STM802SM6E is sourced from the original manufacturer or authorized distributors?
All STM802SM6E 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 STM802SM6E meets industry standards.
7.What is the process for return or replacement of STM802SM6E?
All STM802SM6E units undergo pre-shipment inspection (PSI). If there is an issue with STM802SM6E, 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 STM802SM6E part is unused and in its original packaging.
Return procedure for STM802SM6E:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
STM802SM6E Tags
-
MIC826SYMT-TR
Microchip Technology
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APX803S-31SA-7
Diodes Incorporated
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APX803L20-29SA-7
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EM6325CXSP5B-2.9+
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MCP120T-300I/TT
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MCP130T-315I/TT
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MCP120T-475I/TT
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