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STMicroelectronics STM802RM6F
- Part No.:
- STM802RM6F
- Manufacturer:
- STMicroelectronics
- Category:
- Supervisors
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
STM802RM6F.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:434
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Product details
Overview
STM802RM6F 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 reset assertion down to VCC = 1.0 V and supports external LPSRAM backup in embedded control systems requiring reliable power monitoring and non-volatile memory protection.
For engineers reviewing the STM802RM6F datasheet, STM802RM6F pinout, STM802RM6F application, or STM802RM6F equivalent, key selection criteria include guaranteed RST assertion at low VCC, 200 ms typical reset timeout (trec), automatic VCC/VBAT switchover at 2.4 V, 40 µA typical supply current, and compatibility with SO8 packaging for space-constrained industrial PCBs.
Technical Context
The STM802RM6F integrates a precision voltage reference and comparator to monitor VCC against a fixed reset threshold (VRST), asserting RST when VCC drops below 2.63 V (typ) or during MR activation or watchdog timeout. Its internal trec generator ensures minimum 200 ms reset pulse width after power-up or fault recovery.
It implements automatic battery switchover via a P-channel MOSFET switch between VCC and VBAT, routing supply to VOUT based on VCC vs. VSW (2.4 V) comparison. The push-pull RST output drives microprocessor reset inputs directly without external pull-ups, while PFI/PFO provides early power-fail warning with 1.25 V threshold and 10 µs propagation delay.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 2.63 V (typ); ensures reliable MCU reset before brownout affects core logic |
| Reset Timeout (trec) | 200 ms (typ); provides sufficient hold time for full system initialization |
| Watchdog Timeout | 1.6 s (typ); detects stalled firmware within deterministic safety window |
| VCC Switchover Voltage | 2.4 V (VSW); triggers seamless LPSRAM backup before main supply collapse |
| Supply Current | 40 µA (typ); enables long-term operation in battery-backed systems |
| Battery Supply Current | 0.4 µA (typ); minimizes backup battery drain during extended power loss |
| Operating Temperature | –40 °C to +85 °C; qualified for industrial environments without derating |
Pinout & Package
STM802RM6F is housed in an 8-pin SO8 (Small Outline) package with standard 1.27 mm pitch, suitable for reflow soldering and automated assembly. Pin functions are validated per STMicroelectronics DocID10519 Rev 10.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| PFO | Power-fail output | Push-pull signal indicating imminent VCC failure; asserts low when PFI < 1.25 V or VCC < 2.4 V |
| PFI | Power-fail input | Monitors auxiliary rail or scaled VCC; sets PFO low when voltage drops below threshold |
| WDI | Watchdog input | Edge-sensitive trigger; reset asserted if no transition occurs within 1.6 s |
| RST | Active-low reset output | Push-pull, drives MCU reset pin directly; guaranteed low for 0 V < VCC < 2.63 V |
| VCC | Main supply input | 3 V nominal system rail; powers internal circuitry and enables VOUT sourcing |
| VOUT | SRAM supply output | Switches between VCC and VBAT to maintain LPSRAM voltage during main power loss |
| VBAT | Backup battery input | Accepts 1.0–5.5 V battery; supplies VOUT when VCC falls below 2.4 V |
| VSS | Ground reference | Common return path for all analog and digital functions; requires low-impedance PCB connection |
Key Features
| Feature | Design Value |
|---|---|
| Guaranteed RST assertion down to VCC = 1.0 V | Ensures fail-safe reset even during deep brownout, critical for data integrity in industrial controllers |
| Automatic battery switchover at 2.4 V | Enables zero-interruption SRAM backup without software intervention or external logic |
| 200 ms reset timeout with internal timer | Eliminates need for external RC timing components, reducing BOM count and layout area |
| 40 µA typical supply current | Supports always-on monitoring in energy-sensitive applications like remote sensors and metering |
| Power-fail comparator with 1.25 V PFI threshold | Provides configurable early-warning signal for controlled shutdown or state save before power loss |
Applications
| Industrial PLC I/O Module | Smart Energy Meter |
|---|---|
Use Scenario: Continuous operation in factory-floor cabinets with fluctuating 3 V rails and occasional mains interruption. IC Role / Device Role / Timing Role: Supervises MCU power domain, asserts RST on brownout, switches VOUT to backup battery to retain I/O configuration and last-cycle diagnostics. Use Value: Prevents spurious resets and preserves volatile register states during 10–500 ms grid dips, meeting IEC 61000-4-11 immunity requirements. |
Use Scenario: Tamper-resistant utility meter with real-time clock and EEPROM logging powered by coin cell during AC outage. IC Role / Device Role / Timing Role: Monitors 3.3 V regulator output; triggers PFO alert at 1.25 V PFI threshold to initiate secure data flush before VCC drops below 2.4 V and VOUT switches to VBAT. Use Value: Enables deterministic 200 ms window for CRC-protected flash write completion prior to full backup mode entry. |
| Medical Infusion Pump Controller | Automotive Body Control Module (BCM) |
Use Scenario: Battery-powered portable device requiring FDA-compliant power fail response and SRAM retention during battery swap. IC Role / Device Role / Timing Role: Generates clean RST pulse on VCC sag; uses VOUT to sustain LPSRAM holding therapy parameters and dose history during hot-swap of primary Li-ion pack. Use Value: Guarantees RST remains valid down to 1.0 V VCC, ensuring MCU enters safe state before SRAM voltage collapses below 1.8 V. |
Use Scenario: 12 V automotive system with 3.3 V LDO supplying MCU and CAN transceiver, subject to load dump and cold crank transients. IC Role / Device Role / Timing Role: Detects VCC dip below 2.63 V during cranking; holds RST active for 200 ms to prevent MCU lockup, while PFO alerts BCM firmware to suspend non-critical loads. Use Value: Meets ISO 7637-2 Pulse 4 immunity by maintaining reset assertion through 500 ms cranking event without external capacitor assistance. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX691ACSA+ | Higher reset threshold (3.08 V), no watchdog timer, 12 µA supply current | Lacks watchdog supervision; suited for simple reset-only use cases without firmware stall detection | Select when only power-on reset and brownout detection are required, and ultra-low quiescent current is prioritized over watchdog safety |
| TPS3808G12DBVR | Adjustable reset threshold (via external resistor), 350 ms min trec, 2.5 µA IQ | Requires external resistor network for threshold setting; no battery switchover or PFI/PFO | Choose when precise reset voltage tuning is needed and backup SRAM support is handled separately |
Compared with MAX691ACSA+ and TPS3808G12DBVR, STM802RM6F uniquely combines fixed 2.63 V reset, integrated watchdog, automatic VCC/VBAT switchover, and PFI/PFO in one SO8 package-making it optimal for cost-sensitive industrial systems needing comprehensive power supervision without design overhead.
Availability
STM802RM6F is available at Aetrix Electronics and suitable for industrial PLCs, smart energy meters, medical infusion pumps, and automotive body control modules requiring stable component supply across extended product lifecycles.
Supply support for STM802RM6F 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 sensor solutions for industrial, automotive, and consumer markets.
The STM690/704/795/802/804/805/806 family was engineered specifically for robust microprocessor supervision in harsh industrial environments, emphasizing guaranteed reset behavior, battery-backed SRAM support, and integrated power-fail warning.
FAQ
What is the function of the Vccsw pin on STM802RM6F?
Vccsw is a push-pull output that signals VOUT's power source: high when VOUT is supplied by VBAT (battery backup mode), low when supplied by VCC. It can drive the gate of an external PMOS transistor to extend IOUT beyond the internal 75 mA limit, enabling higher-current SRAM backup configurations.
Does STM802RM6F support both active-high and active-low reset outputs?
No. STM802RM6F provides only an active-low push-pull RST output. The datasheet confirms RST (not RST) functionality for this variant; active-high open-drain RST is exclusive to STM804/805 variants per Table 1 and Figure 1.
Can the watchdog timer be disabled on STM802RM6F?
No. The watchdog timer cannot be disabled-it triggers reset if WDI remains static (high or low) for ≥1.6 s. Floating WDI is not permitted; it must be actively toggled by the MCU or tied to a known logic level with appropriate edge generation.
How does STM802RM6F handle VBAT > VCC conditions?
STM802RM6F does not connect VBAT to VOUT when VBAT exceeds VCC unless VCC falls below VSW (2.4 V). This prevents reverse current flow and unintended battery discharge during normal operation, ensuring backup power is used only during actual VCC failure.
STM802RM6F Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- 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
STM802RM6F FAQ
1.How can I place an order for STM802RM6F through Aetrix?
Please submit a Request for Quotation (RFQ) for STM802RM6F 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 STM802RM6F reliable?
The price and inventory of STM802RM6F are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STM802RM6F is usually 5 days.
3.What payment methods are accepted for STM802RM6F?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STM802RM6F transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STM802RM6F?
STM802RM6F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STM802RM6F 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 STM802RM6F?
For technical support, including STM802RM6F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STM802RM6F requirements.
6.How does Aetrix verify that STM802RM6F is sourced from the original manufacturer or authorized distributors?
All STM802RM6F 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 STM802RM6F meets industry standards.
7.What is the process for return or replacement of STM802RM6F?
All STM802RM6F units undergo pre-shipment inspection (PSI). If there is an issue with STM802RM6F, 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 STM802RM6F part is unused and in its original packaging.
Return procedure for STM802RM6F:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
STM802RM6F Tags
-
MIC826SYMT-TR
Microchip Technology
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APX803S-31SA-7
Diodes Incorporated
-
APX803L20-29SA-7
Diodes Incorporated
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TPS3828-33DBVR
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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
Microchip Technology
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MCP120T-475I/TT
Microchip Technology
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MCP111T-300E/TT
Microchip Technology
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MCP120T-315I/TT
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MCP809T-315I/TT
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