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STMicroelectronics STM704SDS6F
- Part No.:
- STM704SDS6F
- Manufacturer:
- STMicroelectronics
- Category:
- Supervisors
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
STM704SDS6F.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,932
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Product details
Overview
STM704SDS6F from STMicroelectronics is a 3 V industrial-grade microprocessor supervisory IC with manual reset input, power-fail comparator (PFI/PFO), automatic battery switchover, and guaranteed RST assertion down to VCC = 1.0 V. It features 200 ms typical reset timeout (trec), 40 µA typical supply current, and operates from –40 °C to +85 °C in an SO8 package. It is used in embedded systems requiring reliable power monitoring and non-volatile SRAM backup.
For engineers reviewing the STM704SDS6F datasheet, STM704SDS6F pinout, STM704SDS6F application, or STM704SDS6F equivalent, key selection criteria include reset threshold accuracy, battery switchover behavior, PFI/PFO response timing, MR debounce tolerance, and compatibility with LPSRAM backup architectures.
Technical Context
The STM704 implements a precision voltage reference and comparator to monitor VCC against a fixed reset threshold (VRST ≈ 2.93 V). Reset assertion is triggered by VCC drop below VRST, MR low pulse, or (not applicable here) watchdog timeout - though the STM704 lacks WDI functionality per datasheet Table 1 and Section 2.3.
It integrates dual power-path control: VOUT switches between VCC and VBAT using an internal P-channel MOSFET when VCC crosses VSW = 2.4 V; PFI senses external supply decay and drives push-pull PFO low within 10 µs (typ) of VPFI breach, enabling early power-fail warning for system save operations.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 2.93 V (typ); ensures MCU reset before brownout-induced code corruption at 3 V nominal supply |
| Reset Timeout (trec) | 200 ms (typ); provides sufficient hold time for full MCU initialization and peripheral stabilization |
| Supply Current | 40 µA (typ) at VCC = 3.3 V; enables low-power operation in always-on monitoring circuits |
| Battery Current | 0.4 µA (typ) in backup mode; minimizes drain on coin-cell or Li-SOCl₂ batteries during extended outages |
| Operating Temp | –40 °C to +85 °C; qualified for industrial environments including factory automation and metering |
| Power-Fail Threshold | VPFI = 2.63 V (typ); triggers PFO before VCC drops below MCU minimum operating voltage |
| VCC Switchover Voltage | VSW = 2.4 V; defines transition point where VOUT switches from VCC to VBAT to sustain LPSRAM |
Pinout & Package
STM704SDS6F 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 collapse; drives interrupt or NMI line directly |
| 2: VOUT | Supply output | Switched output delivering VCC or VBAT to external LPSRAM; supports up to 75 mA continuous load |
| 3: VCC | Main supply input | Primary 3 V system rail; monitored for reset generation and switchover control |
| 4: Vccsw | VCC switch indicator | Push-pull logic output high during battery backup; used to enable external PMOS for >75 mA IOUT |
| 5: VSS | Ground | System reference node; must be low-impedance connection to minimize noise coupling into reset comparator |
| 6: MR | Manual reset input | Active-low, internally pulled up (40 kΩ); accepts TTL/CMOS logic or momentary switch to GND without external components |
| 7: RST | Active-low reset output | Push-pull output asserted low during fault conditions; guarantees valid state down to VCC = 1.0 V |
| 8: PFI | Power-fail input | Analog input monitoring auxiliary supply; compared to VPFI = 2.63 V to generate early warning before VCC failure |
Key Features
| Feature | Design Value |
|---|---|
| Guaranteed RST assertion to 1.0 V | Ensures deterministic reset even during deep brownout, preventing MCU latch-up or undefined state |
| Automatic battery switchover | VOUT transitions from VCC to VBAT at VSW = 2.4 V with <10 µs delay, preserving SRAM data without software intervention |
| Integrated power-fail comparator | PFI/PFO pair provides hardware-level early warning (≥100 µs advance notice) before VCC dropout reaches critical level |
| Manual reset with internal pull-up | MR requires no external resistor; supports direct switch-to-GND interface with built-in noise immunity via 0.1 µF cap option |
| Low quiescent current in backup mode | 0.4 µA typ battery drain extends 10-year coin-cell life in infrequently powered systems like utility meters |
Applications
| Industrial PLC Controller | Smart Electricity Meter |
|---|---|
|
Use Scenario: Continuous operation in unattended factory-floor controllers with periodic firmware updates and volatile configuration storage. IC Role / Device Role / Timing Role: Supervises 3.3 V MCU supply, asserts RST on brownout, and maintains LPSRAM via VOUT/VBAT switchover during brief AC interruptions. Use Value: Prevents corrupted parameter writes during power sag; enables seamless recovery without manual reboot or EEPROM wear. |
Use Scenario: Revenue-grade metering device storing tariff schedules and consumption logs in external LPSRAM across multi-year deployments. IC Role / Device Role / Timing Role: Monitors main supply (PFI), triggers PFO interrupt for last-gasp data save, then sustains SRAM via VOUT during battery-only operation. Use Value: Guarantees integrity of billing-critical data during grid instability; eliminates need for costly FRAM or battery-backed NVSRAM. |
| Point-of-Sale Terminal | Building Automation Sensor Node |
|
Use Scenario: Retail terminal with flash-based firmware and RAM-resident transaction buffers, subject to unpredictable AC outages. IC Role / Device Role / Timing Role: Generates clean, glitch-free RST pulse on power loss; uses MR for field-service hard reset without opening enclosure. Use Value: Eliminates boot-loop failures after power interruption; reduces field service calls by enabling user-accessible reset. |
Use Scenario: Wireless HVAC sensor node powered by energy harvesting, with intermittent 3.3 V rail and local SRAM cache. IC Role / Device Role / Timing Role: Detects VCC collapse via PFI, asserts PFO to trigger BLE transmission of cached data, then holds SRAM via VBAT until next harvest cycle. Use Value: Maximizes data reliability in duty-cycled systems; avoids packet loss during transient power gaps. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar supervisor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX691ACSA+ | Higher reset threshold (4.65 V), no PFI/PFO, includes watchdog timer | Designed for 5 V systems; lacks power-fail warning capability required for predictive shutdown | Choose only if migrating legacy 5 V designs and watchdog function is mandatory |
| TPS3808G33DBVR | Adjustable reset threshold (via external resistor), 360 ms trec, no battery switchover or PFI | Optimized for flexible reset timing in battery-powered IoT nodes; no LPSRAM support circuitry | Select when precise threshold tuning is needed and VOUT/VBAT functionality is handled externally |
Compared with STM704SDS6F, MAX691ACSA+ serves 5 V domains but omits power-fail warning, while TPS3808G33DBVR offers threshold flexibility at the cost of integrated battery management - making STM704SDS6F uniquely suited for 3 V LPSRAM backup with early fault detection.
Availability
STM704SDS6F is available at Aetrix Electronics and suitable for industrial PLC controllers, smart electricity meters, point-of-sale terminals, and building automation sensor nodes requiring stable component supply across long product lifecycles.
Supply support for STM704SDS6F 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 STM704 belongs to ST's supervisor IC product line, engineered specifically for robust power monitoring and non-volatile memory backup in resource-constrained 3 V embedded systems.
FAQ
Does STM704SDS6F include a watchdog timer?
No. The STM704SDS6F does not feature a watchdog timer, as confirmed in Table 1 and Section 2.3 of the official datasheet (DocID10519 Rev 10), which explicitly states "NOT available on STM704/795/806". Its supervision relies solely on VCC monitoring, MR input, and PFI detection.
What is the maximum load current supported on VOUT?
VOUT supports up to 75 mA continuous output current when sourcing from VCC or VBAT, as specified in Section 1.1.7 and Figure 26–27 of the datasheet. For higher loads, the Vccsw output can drive an external PMOS transistor to extend current capability beyond 75 mA.
Can PFI be left unconnected if unused?
No. Per Section 1.1.5, PFI must be connected to ground if unused. Leaving it floating may cause erratic PFO behavior due to noise sensitivity, as the internal comparator input is not internally terminated. A grounded PFI ensures predictable high-impedance disable of the power-fail function.
Is STM704SDS6F compatible with lithium thionyl chloride (Li-SOCl₂) backup batteries?
Yes. The 0.4 µA typical battery current (Section 1, Features) and VBAT input rating allowing VBAT > VCC (Section 1.1.11) make STM704SDS6F suitable for use with Li-SOCl₂ cells, which provide high energy density and ultra-low self-discharge - ideal for 10+ year metering applications.
STM704SDS6F Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm 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-TSSOP
STM704SDS6F FAQ
1.How can I place an order for STM704SDS6F through Aetrix?
Please submit a Request for Quotation (RFQ) for STM704SDS6F 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 STM704SDS6F reliable?
The price and inventory of STM704SDS6F are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STM704SDS6F is usually 5 days.
3.What payment methods are accepted for STM704SDS6F?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STM704SDS6F transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STM704SDS6F?
STM704SDS6F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STM704SDS6F 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 STM704SDS6F?
For technical support, including STM704SDS6F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STM704SDS6F requirements.
6.How does Aetrix verify that STM704SDS6F is sourced from the original manufacturer or authorized distributors?
All STM704SDS6F 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 STM704SDS6F meets industry standards.
7.What is the process for return or replacement of STM704SDS6F?
All STM704SDS6F units undergo pre-shipment inspection (PSI). If there is an issue with STM704SDS6F, 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 STM704SDS6F part is unused and in its original packaging.
Return procedure for STM704SDS6F:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
STM704SDS6F 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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