My Inquiry
My Account
STMicroelectronics STM704RM6F
- Part No.:
- STM704RM6F
- Manufacturer:
- STMicroelectronics
- Category:
- Supervisors
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
STM704RM6F.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,691
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
STM704RM6F 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 STM704RM6F datasheet, STM704RM6F pinout, STM704RM6F application, or STM704RM6F equivalent, this device serves as a precision voltage-monitoring supervisor for embedded systems requiring reliable power-up/power-down sequencing, nonvolatile SRAM backup control, and system-level fault detection in space-constrained industrial designs.
Technical Context
The STM704RM6F integrates 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 during MR activation. Its internal trec generator ensures minimum 200 ms reset pulse width after power-up or fault recovery.
It implements automatic battery switchover via internal P-channel MOSFET: VOUT connects to VCC above VSW = 2.4 V, and switches to VBAT when VCC falls below VSW. The PFI/PFO pair provides early power-fail warning with VPFI = 1.25 V threshold and push-pull PFO output.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold (VRST) | 2.63 V ±1.5% - guarantees deterministic MCU reset initiation at defined VCC undervoltage condition |
| Reset Timeout (trec) | 200 ms typ - ensures sufficient hold time for processor initialization and peripheral stabilization |
| Battery Supply Current | 0.4 µA typ - enables multi-year backup operation from coin-cell batteries without significant drain |
| Power-Fail Threshold (VPFI) | 1.25 V - triggers PFO low before VCC reaches critical levels, allowing firmware-initiated save operations |
| Operating Temperature | –40 °C to +85 °C - qualified for industrial environments including factory automation and metering |
| VCC Switchover Voltage (VSW) | 2.4 V - defines precise transition point between main supply and battery backup for seamless SRAM retention |
| Supply Current (VCC mode) | 40 µA typ - minimizes impact on primary power rail during normal operation |
Pinout & Package
STM704RM6F 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 | Push-pull power-fail output - asserts low when VCC < VSW or PFI < 1.25 V; drives interrupt or flag logic directly |
| 2 | VOUT | Switched supply output - delivers regulated VCC or VBAT to external LPSRAM; supports up to 75 mA load |
| 3 | VCC | Main supply input - powers internal circuitry and sources VOUT when above 2.4 V; monitored for reset generation |
| 4 | RST | Active-low push-pull reset output - drives MCU reset pin low for ≥200 ms during power faults or manual reset |
| 5 | VSS | Ground reference - common return path for all internal functions and I/O; must be low-impedance |
| 6 | MR | Manual reset input - active-low, internally pulled up to VOUT; debounced by trec timer; no external RC needed |
| 7 | PFI | Power-fail input - monitors auxiliary rail or scaled VCC; asserts PFO when voltage falls below 1.25 V |
| 8 | VBAT | Backup battery input - supplies VOUT when VCC fails; accepts voltages > VCC; connect to VCC if unused |
Key Features
| Feature | Design Value |
|---|---|
| Guaranteed RST assertion down to VCC = 1.0 V | Ensures fail-safe reset even during deep brown-out, preserving system integrity when primary supply collapses |
| Automatic battery switchover with 2.4 V threshold | Enables seamless transition to backup power without software intervention or external FETs |
| Integrated 200 ms reset timeout generator | Eliminates need for external RC timing components while maintaining precise, temperature-stable delay |
| 0.4 µA battery supply current (typ) | Extends coin-cell life beyond 10 years in always-on backup applications such as real-time clocks or configuration memory |
| Push-pull PFO with 1.25 V PFI threshold | Provides immediate, noise-immune power-fail alert for firmware-triggered data preservation before shutdown |
Applications
| Industrial PLC Controller | Smart Energy Meter |
|---|---|
Use Scenario: Maintains SRAM contents during grid voltage sags or meter replacement. IC Role / Device Role / Timing Role: Supervises 3.3 V MCU supply, switches VOUT to CR2032 battery upon VCC drop below 2.4 V, asserts RST to halt firmware execution. Use Value: Prevents loss of tariff data, time-of-use logs, and calibration parameters during brief outages. |
Use Scenario: Preserves billing registers and tamper-event history during AC power interruption. IC Role / Device Role / Timing Role: Monitors DC bus derived from rectified mains; triggers PFO at 1.25 V to initiate EEPROM write before VCC collapse. Use Value: Guarantees regulatory-compliant data retention without external supervisors or discrete comparators. |
| Factory Automation HMI | Medical Diagnostic Monitor |
Use Scenario: Secures display configuration and calibration settings during unexpected power cycling. IC Role / Device Role / Timing Role: Provides 200 ms RST pulse on power-up to synchronize ARM Cortex-M4 boot sequence and LCD controller initialization. Use Value: Eliminates display artifacts and firmware lockups caused by insufficient reset hold time. |
Use Scenario: Retains patient session data and sensor calibration offsets during battery-swapped maintenance. IC Role / Device Role / Timing Role: Uses MR pin for hardware-initiated safe shutdown; VOUT powers SRAM storing last ECG waveform buffer. Use Value: Meets IEC 62304 Class C requirement for deterministic state preservation during power transitions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6326US26D3+ | Fixed 2.63 V reset threshold, 200 ms trec, but lacks PFI/PFO and battery switchover | Suitable only for basic reset supervision; cannot support SRAM backup or power-fail warning | Select when cost-sensitive designs require only reset generation without battery management |
| TPS3808G33DBVR | 2.93 V reset threshold, adjustable trec (200 ms–10 s), no MR or PFI/PFO, no battery switchover | Requires external circuitry for manual reset and power-fail detection; no VOUT switching capability | Choose for higher-VCC systems (>3.0 V) where extended timeout flexibility outweighs integrated features |
Compared with MAX6326US26D3+ and TPS3808G33DBVR, the STM704RM6F uniquely combines guaranteed sub-1 V reset assertion, integrated battery switchover, and dual-function PFI/PFO in a single SO8 package-enabling compact, self-contained supervision for 3 V SRAM-backed systems without external FETs or comparators.
Availability
STM704RM6F is available at Aetrix Electronics and suitable for industrial PLC controllers, smart energy meters, factory automation HMIs, and medical diagnostic monitors requiring stable component supply across long production lifecycles.
Supply support for STM704RM6F 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 precision voltage supervisor product line, engineered specifically for robust, low-power microprocessor monitoring and nonvolatile memory backup in harsh industrial environments.
FAQ
What is the function of the MR pin on STM704RM6F?
The MR (manual reset) pin is an active-low input with internal 40 kΩ pull-up. Driving MR low asserts RST for the full trec duration (200 ms typ), then holds RST low for trec after MR returns high. It requires no external debounce components and supports direct connection to momentary switches or logic outputs.
Does STM704RM6F include a watchdog timer?
No. The STM704RM6F does not include a watchdog timer. Per the official datasheet (DocID10519 Rev 10, Section 2.3), watchdog functionality is explicitly excluded from the STM704 and STM806 variants - it is only present in STM690, STM802, STM804, and STM805.
How does the VOUT/VBAT switchover operate during power failure?
VOUT automatically switches from VCC to VBAT when VCC falls below VSW = 2.4 V. The internal P-channel MOSFET connects VBAT to VOUT with ~100 Ω on-resistance. When VCC rises above VSW + hysteresis (~2.5 V), VOUT reconnects to VCC. VBAT may exceed VCC, and no external diode is required.
Can PFI be left unconnected if not used?
No. The PFI pin must be connected to ground if unused. According to the datasheet (Section 1.1.5), leaving PFI floating may cause unpredictable PFO behavior due to noise sensitivity. Grounding PFI disables the power-fail comparator function while ensuring stable PFO high output.
STM704RM6F 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
STM704RM6F FAQ
1.How can I place an order for STM704RM6F through Aetrix?
Please submit a Request for Quotation (RFQ) for STM704RM6F 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 STM704RM6F reliable?
The price and inventory of STM704RM6F are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STM704RM6F is usually 5 days.
3.What payment methods are accepted for STM704RM6F?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STM704RM6F transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STM704RM6F?
STM704RM6F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STM704RM6F 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 STM704RM6F?
For technical support, including STM704RM6F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STM704RM6F requirements.
6.How does Aetrix verify that STM704RM6F is sourced from the original manufacturer or authorized distributors?
All STM704RM6F 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 STM704RM6F meets industry standards.
7.What is the process for return or replacement of STM704RM6F?
All STM704RM6F units undergo pre-shipment inspection (PSI). If there is an issue with STM704RM6F, 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 STM704RM6F part is unused and in its original packaging.
Return procedure for STM704RM6F:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
STM704RM6F Tags
-
MIC826SYMT-TR
Microchip Technology
-
APX803S-31SA-7
Diodes Incorporated
-
APX803L20-29SA-7
Diodes Incorporated
-
TPS3828-33DBVR
Texas Instruments
-
V6340RSP3B+
EM Microelectronic
-
EM6325CXSP5B-2.9+
EM Microelectronic
-
MCP120T-300I/TT
Microchip Technology
-
MCP130T-315I/TT
Microchip Technology
-
MCP120T-475I/TT
Microchip Technology
-
MCP111T-300E/TT
Microchip Technology
-
MCP120T-315I/TT
Microchip Technology
-
MCP809T-315I/TT
Microchip Technology
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
