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STMicroelectronics STM704SM6F
- Part No.:
- STM704SM6F
- Manufacturer:
- STMicroelectronics
- Category:
- Supervisors
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
STM704SM6F.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8SO
- Quantity:
- Payment:
- Shipping:
Inventory:3,411
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Product details
Overview
STM704SM6F from STMicroelectronics is a 3 V industrial-grade microprocessor supervisory IC with battery switchover, active-low push-pull RST output, manual reset (MR) input, power-fail comparator (PFI/PFO), and guaranteed reset assertion down to VCC = 1.0 V. It provides 200 ms typical reset timeout (trec), 0.4 µA typical battery supply current, and operates from –40 °C to +85 °C in SO8 package.
For engineers reviewing the STM704SM6F datasheet, STM704SM6F pinout, STM704SM6F application, or STM704SM6F equivalent, this device is selected for reliable power monitoring, non-volatile SRAM backup control, and system-level reset integrity in embedded instrumentation, industrial controllers, and battery-backed data loggers.
Technical Context
The STM704 implements a precision voltage reference and comparator to monitor VCC against a fixed reset threshold (VRST ≈ 2.63 V), asserting RST low when VCC drops below VRST or MR is pulled low. Reset remains asserted for ≥200 ms after VCC recovery or MR release, ensuring MCU initialization stability.
It integrates automatic battery switchover: when VCC falls below VSW = 2.4 V, VOUT disconnects from VCC and connects to VBAT via an internal P-channel MOSFET switch; Vccsw toggles high during switchover to enable external PMOS gate drive for >75 mA IOUT. PFI/PFO provide early power-fail warning with push-pull PFO output.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold (VRST) | 2.63 V ±1.5% - ensures reset activation before MCU brown-out, with hysteresis for noise immunity |
| Reset Timeout (trec) | 200 ms (typ) - guarantees sufficient hold time for full MCU boot sequence |
| Battery Supply Current | 0.4 µA (typ) - enables multi-year backup operation from coin-cell batteries |
| Supply Current (VCC) | 40 µA (typ) - minimizes impact on main power rail in always-on systems |
| Operating Temperature | –40 °C to +85 °C - qualified for industrial environments without derating |
| VCC Switchover Voltage (VSW) | 2.4 V - triggers seamless transition to battery before critical VCC collapse |
| PFO Output Type | Push-pull - drives logic inputs directly without external pull-up resistors |
Pinout & Package
STM704SM6F 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; asserts when PFI < VPFI or VCC < VSW |
| 2: VOUT | Supply output for LPSRAM | Switched output connected to VCC (above VSW) or VBAT (below VSW); powers external low-power SRAM |
| 3: VCC | Main supply input | Primary 3 V system rail; monitored for reset generation and switchover control |
| 4: Vccsw | VCC switch status output | Push-pull signal high during battery backup mode; drives external PMOS gate for higher IOUT |
| 5: VSS | Ground reference | Common return path for all internal circuitry and I/O pins |
| 6: MR | Manual reset input | Active-low input with 40 kΩ internal pull-up; initiates reset on logic low, holds for trec after release |
| 7: RST | Active-low reset output | Push-pull output asserted low during VCC fault, MR assertion, or power-up; meets MCU reset timing requirements |
| 8: VBAT | Backup battery input | Accepts 1.0–5.5 V backup source; automatically engages when VCC falls below VSW |
Key Features
| Feature | Design Value |
|---|---|
| Guaranteed RST assertion down to VCC = 1.0 V | Ensures deterministic reset even during deep brown-out conditions, protecting MCU state integrity |
| Automatic battery switchover with Vccsw flag | Enables seamless SRAM retention during main power loss while signaling switchover to external circuitry |
| Integrated power-fail comparator (PFI/PFO) | Provides programmable early warning of supply decay, allowing controlled data save before reset |
| 200 ms reset timeout with temperature-stable trec generator | Delivers consistent reset pulse width across –40 °C to +85 °C, eliminating external RC timing components |
| Low 0.4 µA battery current in backup mode | Extends coin-cell life beyond 10 years in typical data-logger applications with infrequent writes |
Applications
| Industrial Data Logger | Programmable Logic Controller (PLC) |
|---|---|
|
Use Scenario: Continuous sensor data acquisition with volatile SRAM buffer and battery-backed real-time clock. IC Role / Device Role / Timing Role: Supervises 3 V main rail, switches SRAM to coin-cell during AC outage, asserts reset if VCC dips during firmware update. Use Value: Prevents SRAM corruption and ensures deterministic reboot after power interruption, meeting IEC 61000-4-29 immunity requirements. |
Use Scenario: Modular I/O controller requiring fail-safe reset and non-volatile configuration storage. IC Role / Device Role / Timing Role: Monitors CPU supply, generates clean reset pulse on undervoltage, signals power-fail to FPGA for safe I/O freeze. Use Value: Eliminates need for discrete voltage monitor + reset generator + switchover FET, reducing BOM count by 4 components. |
| Medical Infusion Pump | Smart Energy Meter |
|
Use Scenario: Battery-powered portable pump storing therapy history in LPSRAM between charging cycles. IC Role / Device Role / Timing Role: Provides tamper-resistant reset supervision and automatic SRAM backup during battery swap. Use Value: Meets IEC 62304 Class C software safety requirements by guaranteeing reset validity down to 1.0 V during brown-out. |
Use Scenario: Revenue-grade meter with metrology SoC and EEPROM-backed event logging. IC Role / Device Role / Timing Role: Detects grid voltage sag via PFI, triggers PFO to initiate flash write before VCC collapse. Use Value: Enables reliable last-gasp data commit within 2.4 V–2.63 V window, preventing meter reading loss during brown-out. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar supervisor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6326US26D3+ | Single-supply 2.63 V reset only; no PFI/PFO, no battery switchover, no MR input | Suitable for basic reset-only use cases without SRAM backup or power-fail warning | Select when only reset supervision is required and cost is primary constraint |
| TPS3808G12DBVR | Adjustable reset threshold (1.2–5.5 V); no battery switchover or PFI/PFO; includes watchdog timer | Used where flexible threshold setting is needed, but lacks integrated SRAM power management | Choose when system requires programmable reset point and watchdog, but uses separate battery circuitry |
Compared with MAX6326US26D3+ and TPS3808G12DBVR, STM704SM6F uniquely integrates battery switchover, PFI/PFO, and MR in one SO8 package-enabling compact, self-contained SRAM supervision without external FETs or comparators.
Availability
STM704SM6F is available at Aetrix Electronics and suitable for industrial data loggers, programmable logic controllers, medical infusion pumps, and smart energy meters requiring stable component supply across extended product lifecycles.
Supply support for STM704SM6F 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 STM690/704/795/802/804/805/806 family was engineered specifically for robust microprocessor supervision in battery-backed embedded systems-prioritizing low quiescent current, guaranteed reset behavior under brown-out, and integrated SRAM power management.
FAQ
What is the function of the Vccsw pin on STM704SM6F?
Vccsw is a push-pull output that goes high when VOUT switches from VCC to VBAT during power failure, and low when switching back. Its purpose is to drive the gate of an external PMOS transistor, enabling higher current delivery (>75 mA) to external LPSRAM during battery backup-beyond the internal switch's capability.
Can STM704SM6F be used without a backup battery?
Yes. When no battery is used, connect both VBAT and VOUT to the main VCC rail. In this configuration, the device still provides full reset supervision, power-fail detection via PFI/PFO, and manual reset via MR-but battery switchover functionality is disabled and Vccsw remains low.
Does STM704SM6F include a watchdog timer?
No. The STM704SM6F does not include a watchdog timer. According to the official STMicroelectronics datasheet (DocID10519 Rev 10), watchdog functionality is explicitly excluded from the STM704 and STM806 variants-unlike STM690, STM802, STM804, and STM805.
What is the maximum load current supported on the VOUT pin?
VOUT supports up to 75 mA continuous current when powered from VCC or VBAT. This limit is defined by the on-resistance and thermal design of the internal P-channel MOSFET switch. For loads exceeding 75 mA, the Vccsw pin must be used to drive an external PMOS transistor in series with VOUT.
STM704SM6F 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:
- 2.925V
- 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
STM704SM6F FAQ
1.How can I place an order for STM704SM6F through Aetrix?
Please submit a Request for Quotation (RFQ) for STM704SM6F 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 STM704SM6F reliable?
The price and inventory of STM704SM6F are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STM704SM6F is usually 5 days.
3.What payment methods are accepted for STM704SM6F?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STM704SM6F transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STM704SM6F?
STM704SM6F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STM704SM6F 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 STM704SM6F?
For technical support, including STM704SM6F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STM704SM6F requirements.
6.How does Aetrix verify that STM704SM6F is sourced from the original manufacturer or authorized distributors?
All STM704SM6F 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 STM704SM6F meets industry standards.
7.What is the process for return or replacement of STM704SM6F?
All STM704SM6F units undergo pre-shipment inspection (PSI). If there is an issue with STM704SM6F, 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 STM704SM6F part is unused and in its original packaging.
Return procedure for STM704SM6F:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
STM704SM6F Tags
-
MIC826SYMT-TR
Microchip Technology
-
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
Microchip Technology
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MCP809T-315I/TT
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