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STMicroelectronics STM802RM6E
- Part No.:
- STM802RM6E
- Manufacturer:
- STMicroelectronics
- Category:
- Supervisors
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
STM802RM6E.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8SO
- Quantity:
- Payment:
- Shipping:
Inventory:2,944
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Product details
Overview
STM802RM6E from STMicroelectronics is a 3 V microprocessor supervisory IC with battery switchover, active-low RST output, manual reset (MR), watchdog timer (1.6 s typ), and power-fail comparator (PFI/PFO). It guarantees reset assertion down to VCC = 1.0 V and supports external LPSRAM backup in industrial systems requiring reliable power monitoring and non-volatile memory protection.
For engineers reviewing the STM802RM6E datasheet, STM802RM6E pinout, STM802RM6E application, or STM802RM6E equivalent, this page delivers verified technical context, exact pin functions, real-world use cases for SRAM backup and power-fail warning, and validated alternative parts with documented functional differences.
Technical Context
The STM802RM6E integrates a precision voltage reference and comparator to monitor VCC against a 2.63 V reset threshold (VRST) with hysteresis, asserting RST low when VCC drops below VRST or MR is pulled low. Its internal trec generator ensures ≥200 ms reset pulse width after power-up or fault recovery.
It features automatic battery switchover via a P-channel MOSFET switch (VOUT connected to VCC above VSW = 2.4 V; to VBAT below VSW), plus a push-pull PFO output that asserts low on PFI < VPFI (1.25 V typ) or VCC < VSW - enabling early power-fail detection without external circuitry.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold (VRST) | 2.63 V ±1.5% - ensures deterministic MCU reset before brownout affects core logic |
| Reset Timeout (trec) | 200 ms (typ) - provides sufficient hold time for full system initialization |
| Watchdog Timeout (tWD) | 1.6 s (typ) - detects MCU lockup without requiring software intervention |
| Power-Fail Threshold (VPFI) | 1.25 V (typ) - triggers PFO assertion before VCC reaches critical undervoltage level |
| Battery Supply Current | 0.4 µA (typ) - enables multi-year backup operation from coin-cell batteries |
| Operating Temperature | –40 °C to +85 °C - qualified for industrial-grade embedded applications |
| VCC Switchover Voltage (VSW) | 2.4 V - defines precise transition point between main and backup supply paths |
Pinout & Package
STM802RM6E is housed in an 8-pin SO8 (Small Outline Integrated Circuit) package, measuring 4.9 mm × 6.0 mm × 1.75 mm, with standard 1.27 mm pitch and gull-wing leads suitable for automated PCB assembly.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1: PFO | Power-fail output | Push-pull active-low signal indicating imminent VCC failure; drives interrupt or NMI input |
| 2: VOUT | Supply output for LPSRAM | Switched output sourcing from VCC or VBAT; powers external low-power SRAM during main supply loss |
| 3: VCC | Main supply input | Primary 3 V system rail; monitored for reset and switchover decisions |
| 4: Vccsw | VCC switch status output | Push-pull logic-high when VOUT is sourced from VBAT; enables external PMOS control for >75 mA loads |
| 5: VSS | Ground | Reference node for all internal comparators and outputs; must be low-impedance |
| 6: MR | Manual reset input | Active-low input with internal 40 kΩ pull-up; debounced by trec timing - no external RC needed |
| 7: WDI | Watchdog input | Edge-sensitive input; toggling within 1.6 s prevents reset - used for MCU liveliness monitoring |
| 8: RST | Active-low reset output | Push-pull output asserted low during VCC fault, MR activation, or watchdog timeout; drives MCU reset pin directly |
Key Features
| Feature | Design Value |
|---|---|
| Guaranteed RST assertion down to VCC = 1.0 V | Ensures fail-safe reset even during deep brownout, protecting register state and memory integrity |
| Automatic battery switchover with 100 Ω switch | Enables seamless LPSRAM backup without external diodes or FETs; supports SuperCap™ integration |
| Integrated power-fail comparator (PFI/PFO) | Provides programmable early-warning signal (VPFI = 1.25 V) before VCC collapse - avoids last-moment data loss |
| 200 ms reset timeout with temperature stability | trec variation < ±10% over –40 °C to +85 °C - eliminates need for external timing capacitor |
| Low 40 µA operating supply current (typ) | Minimizes impact on primary 3 V rail; compatible with battery-backed systems where quiescent power matters |
Applications
| Industrial PLC Memory Backup | Smart Meter Data Retention |
|---|---|
|
Use Scenario: Maintaining SRAM contents during AC mains interruption or battery replacement in programmable logic controllers. IC Role / Device Role / Timing Role: Supervisory IC providing VOUT switchover, RST hold, and PFO-triggered firmware save before power loss. Use Value: Prevents loss of configuration, I/O state, and runtime variables using integrated 0.4 µA battery mode and 2.4 V switchover. |
Use Scenario: Preserving tariff tables, consumption logs, and cryptographic keys during grid outages in utility meters. IC Role / Device Role / Timing Role: Dual-role supervisor: monitors VCC for reset, asserts PFO to initiate EEPROM write at 1.25 V VPFI threshold. Use Value: Enables deterministic data commit window (≥200 ms trec) before VCC falls below 1.0 V - meeting ANSI C12.22 requirements. |
| Medical Infusion Pump Safety Monitoring | POS Terminal Power Fail Recovery |
|
Use Scenario: Ensuring safe shutdown and parameter retention when main 3 V supply dips due to motor load transients. IC Role / Device Role / Timing Role: Real-time VCC supervisor triggering RST and initiating watchdog-checked firmware recovery sequence. Use Value: Guarantees MCU reset assertion at 2.63 V VRST with ±1.5% tolerance - meets IEC 62304 Class B safety margin. |
Use Scenario: Recovering transaction state after brief power interruption in retail point-of-sale terminals. IC Role / Device Role / Timing Role: Combines MR-initiated reset, PFO-driven log flush, and VOUT-powered SRAM to preserve last sale record. Use Value: Eliminates need for external reset controller or discrete power-fail circuit - reduces BOM count by 3 components. |
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 | No battery switchover, no PFI/PFO, no watchdog; only reset supervisor with 2.93 V threshold | Suitable for basic reset-only use; cannot support SRAM backup or power-fail warning | Select only if system lacks battery, requires no early power-fail signaling, and uses higher VCC rails |
| TPS3808G12DBVR | Adjustable reset threshold (via external resistor), no battery switchover, no PFI/PFO, 200 ms trec | Offers design flexibility for non-standard VCC voltages but omits dual-supply management | Choose when precise threshold tuning is required and backup power path is handled externally |
Compared with STM802RM6E, MAX809SEUR+T lacks battery switchover and power-fail detection - limiting it to simple reset applications - while TPS3808G12DBVR trades integrated backup functionality for adjustable threshold, requiring external components to replicate VOUT/Vccsw behavior.
Availability
STM802RM6E is available at Aetrix Electronics and suitable for industrial PLCs, smart meters, medical infusion pumps, and POS terminals requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for STM802RM6E 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, MCU, power, and sensing solutions for industrial, automotive, and consumer markets.
The STM690/802 family was engineered specifically for robust microprocessor supervision in battery-backed embedded systems - emphasizing low-quiescent-current switchover, precise reset thresholds, and integrated power-fail warning without external components.
FAQ
What is the function of the Vccsw pin on STM802RM6E?
Vccsw is a push-pull output that goes high when VOUT switches from VCC to VBAT, and low when switching back. It provides a logic-level signal to drive the gate of an external PMOS transistor, enabling higher current (>75 mA) backup power delivery to external LPSRAM - extending beyond the internal 100 Ω switch's capability.
Can STM802RM6E operate without a backup battery?
Yes. When no battery is used, VBAT and VOUT must both be connected to VCC. The device operates normally as a reset supervisor and power-fail detector, with RST assertion guaranteed down to VCC = 1.0 V and PFO functioning based on VPFI and VSW thresholds - no battery dependency for core supervision functions.
How does the watchdog timer interact with the MR input?
The watchdog timer is disabled during reset assertion - meaning it stops counting while RST is active (low). When MR is pulled low, RST asserts immediately and holds for trec; the watchdog remains inactive until RST de-asserts and VCC stabilizes above VRST, at which point WDI monitoring resumes - preventing false timeouts during manual reset.
Is the PFO output compatible with 5 V logic systems?
No. PFO is a 3 V push-pull output referenced to VCC (nominal 3 V), with VOH ≈ VCC – 0.3 V and VOL < 0.4 V. Direct connection to 5 V logic inputs risks overvoltage damage. Interface via level-shifter or open-drain buffer with pull-up to 5 V is required for compatibility with 5 V microcontrollers or FPGAs.
STM802RM6E 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:
- 2.625V
- 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
STM802RM6E FAQ
1.How can I place an order for STM802RM6E through Aetrix?
Please submit a Request for Quotation (RFQ) for STM802RM6E 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 STM802RM6E reliable?
The price and inventory of STM802RM6E are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STM802RM6E is usually 5 days.
3.What payment methods are accepted for STM802RM6E?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STM802RM6E transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STM802RM6E?
STM802RM6E orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STM802RM6E 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 STM802RM6E?
For technical support, including STM802RM6E datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STM802RM6E requirements.
6.How does Aetrix verify that STM802RM6E is sourced from the original manufacturer or authorized distributors?
All STM802RM6E 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 STM802RM6E meets industry standards.
7.What is the process for return or replacement of STM802RM6E?
All STM802RM6E units undergo pre-shipment inspection (PSI). If there is an issue with STM802RM6E, 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 STM802RM6E part is unused and in its original packaging.
Return procedure for STM802RM6E:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
STM802RM6E Tags
-
MIC826SYMT-TR
Microchip Technology
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APX803S-31SA-7
Diodes Incorporated
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APX803L20-29SA-7
Diodes Incorporated
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V6340RSP3B+
EM Microelectronic
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EM6325CXSP5B-2.9+
EM Microelectronic
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MCP120T-300I/TT
Microchip Technology
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MCP130T-315I/TT
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MCP120T-475I/TT
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MCP111T-300E/TT
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MCP120T-315I/TT
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