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STMicroelectronics STM704RM6E
- Part No.:
- STM704RM6E
- Manufacturer:
- STMicroelectronics
- Category:
- Supervisors
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
STM704RM6E.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8SO
- Quantity:
- Payment:
- Shipping:
Inventory:3,798
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Product details
Overview
STM704RM6E from STMicroelectronics is a 3 V industrial-grade microprocessor supervisor 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 delivers 200 ms typical reset timeout (trec), 0.4 µA typical battery supply current, and operates from –40 °C to +85 °C - used in embedded systems requiring reliable power monitoring and non-volatile SRAM backup.
For engineers reviewing the STM704RM6E datasheet, STM704RM6E pinout, STM704RM6E application, or STM704RM6E equivalent, key selection criteria include reset threshold accuracy, MR debounce capability, PFI trip voltage (VPFI = 2.63 V), VCC switchover behavior at VSW = 2.4 V, and compatibility with external LPSRAM retention during main supply loss.
Technical Context
The STM704RM6E integrates a precision voltage reference and comparator to monitor VCC against a fixed 2.63 V reset threshold (VRST) with ±1.5% tolerance. Its internal reset timer ensures 200 ms (typ) trec after power-up, MR release, or VCC recovery - independent of supply slew rate.
It implements automatic battery switchover via an internal P-channel MOSFET switch: VOUT connects to VCC when VCC ≥ 2.4 V (VSW), and switches to VBAT when VCC falls below VSW. Vccsw provides a push-pull logic signal indicating switchover state, enabling external PMOS control for >75 mA IOUT.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold (VRST) | 2.63 V ±1.5% - guarantees deterministic MCU reset initiation before brownout affects core logic. |
| Reset Timeout (trec) | 200 ms (typ) - holds RST low long enough to ensure full processor initialization and clock stabilization. |
| VCC Switchover Voltage (VSW) | 2.4 V - triggers seamless VOUT source transition from VCC to VBAT before VRST violation occurs. |
| Battery Supply Current | 0.4 µA (typ) - enables multi-year backup operation from coin-cell batteries without significant drain. |
| Power-Fail Input Threshold (VPFI) | 2.63 V - matches VRST to synchronize PFO assertion with reset activation for coordinated system shutdown. |
| Operating Temperature | –40 °C to +85 °C - qualified for industrial environments including factory automation and metering. |
| Reset Output Type | Active-low push-pull RST - drives standard CMOS/TTL reset inputs without external pull-up. |
Pinout & Package
STM704RM6E is housed in an 8-pin SO8 (Small Outline Integrated Circuit) package, 3.9 mm × 4.9 mm body, 1.27 mm pitch, with gull-wing leads. Pin 1 is marked by a beveled corner or dot.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1: PFO | Power-fail output | Push-pull active-low signal indicating imminent VCC failure; asserts when PFI < 2.63 V or VCC < 2.4 V. |
| 2: VOUT | Supply output for external LPSRAM | Switched output sourcing VCC or VBAT; maintains SRAM VDD during main supply interruption. |
| 3: VCC | Main supply input | Primary 3 V system rail; powers internal circuitry and feeds VOUT when above VSW. |
| 4: Vccsw | VCC switch status output | Push-pull logic-high when VOUT sourced from VBAT; enables external high-current PMOS switch control. |
| 5: VSS | Ground reference | Common return path for all internal functions and output drivers; must be low-impedance. |
| 6: MR | Manual reset input | Active-low input with 40 kΩ internal pull-up; debounced internally - no external RC required. |
| 7: RST | Active-low reset output | Push-pull output asserted low during VCC undervoltage, MR activation, or power-up delay. |
| 8: PFI | Power-fail input | Monitors auxiliary rail or scaled VCC; asserts PFO when voltage drops below 2.63 V. |
Key Features
| Feature | Design Value |
|---|---|
| Guaranteed RST assertion down to VCC = 1.0 V | Ensures reset remains valid even during deep brownout, protecting MCU state integrity. |
| Automatic battery switchover with 100 Ω on-resistance | Minimizes voltage drop (<260 mV @ 2.6 mA) across switch, preserving SRAM retention voltage margin. |
| Integrated 200 ms reset timeout generator | Eliminates need for external RC timing components - reduces BOM count and layout area. |
| Low 40 µA (typ) operating supply current | Reduces system quiescent power draw without compromising supervision responsiveness. |
| MR input with internal 40 kΩ pull-up | Supports direct connection to momentary switch (MR-to-GND); no external biasing needed. |
Applications
| Industrial PLC Controller | Smart Energy Meter |
|---|---|
|
Use Scenario: Maintains real-time clock and tariff data in external LPSRAM during grid voltage sags or outages. IC Role / Device Role / Timing Role: Supervisor monitors 3.3 V rail and switches VOUT to coin-cell battery within 1 µs of VCC falling below 2.4 V. Use Value: Prevents SRAM data corruption and eliminates need for EEPROM write cycles during transient faults. |
Use Scenario: Preserves metering registers and cryptographic keys during utility power interruption. IC Role / Device Role / Timing Role: PFI monitors regulated 3.3 V supply; PFO triggers firmware-controlled shutdown before VCC drops below 2.63 V. Use Value: Enables clean state save with >150 ms warning window - sufficient for flash commit and secure erase. |
| Medical Infusion Pump | Point-of-Sale Terminal |
|
Use Scenario: Ensures therapy log continuity and motor stop command execution during AC adapter disconnect. IC Role / Device Role / Timing Role: MR input accepts nurse-initiated hard reset; RST holds MCU in reset for full 200 ms to prevent partial instruction execution. Use Value: Meets IEC 62304 Class C safety requirement for deterministic fault recovery and state rollback. |
Use Scenario: Retains transaction buffer and encryption keys during brief UPS switchover or battery replacement. IC Role / Device Role / Timing Role: Vccsw output drives external PMOS switch to sustain 500 mA SRAM load beyond internal 75 mA limit. Use Value: Supports fast-recovery boot (<500 ms) without re-authentication or transaction replay. |
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 4.65 V reset threshold; no PFI/PFO; 120 ms trec; 5 V only | Lacks battery switchover and power-fail warning - suitable only for 5 V legacy designs without SRAM backup | Select only if system uses 5 V rail and requires no battery support or early power-fail signaling. |
| TPS3808G12DBVR | Adjustable reset threshold (via resistor divider); 200 ms trec; no MR or PFI; 3.3 V/5 V compatible | Missing manual reset and power-fail comparator - cannot support push-button recovery or predictive shutdown | Prefer when precise threshold tuning is required and MR/PFI functionality is handled elsewhere in system. |
Compared with MAX691ACSA+ and TPS3808G12DBVR, STM704RM6E uniquely combines fixed 2.63 V reset, integrated MR, PFI/PFO, and automatic battery switchover in a single SO8 package - making it optimal for cost-sensitive 3 V industrial systems needing full SRAM retention and fail-safe reset.
Availability
STM704RM6E is available at Aetrix Electronics and suitable for industrial PLC controllers, smart energy meters, medical infusion pumps, and point-of-sale terminals requiring stable component supply across extended product lifecycles.
Supply support for STM704RM6E 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, microcontroller, power, and sensor 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 protection in resource-constrained 3 V embedded systems.
FAQ
What is the function of the Vccsw pin on STM704RM6E?
Vccsw is a push-pull output that goes high when VOUT switches from VCC to VBAT, and low when VOUT reconnects to VCC. It provides a logic-level signal to drive the gate of an external PMOS transistor, enabling higher current (>75 mA) battery-backed SRAM loads beyond the internal switch capability.
Can STM704RM6E operate without a backup battery?
Yes. When no battery is used, connect both VBAT and VOUT directly to VCC. The device functions fully as a reset supervisor and power-fail detector; battery switchover is disabled but all other features - including RST, MR, PFI/PFO, and trec timing - remain active and specified.
Is the MR input debounced internally?
Yes. The MR pin includes internal timing circuitry that ensures reset remains asserted for the full 200 ms trec period after MR returns high, eliminating the need for external RC debounce networks. A 40 kΩ internal pull-up also allows direct switch-to-ground connection without external biasing.
What happens to RST during VCC power-up?
At power-up, RST is held low for 200 ms (typ) after VCC rises above 2.63 V, regardless of MR or PFI state. This ensures the microprocessor completes power stabilization and clock acquisition before release - meeting JEDEC JESD8-12B requirements for reliable boot sequencing.
STM704RM6E 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
STM704RM6E FAQ
1.How can I place an order for STM704RM6E through Aetrix?
Please submit a Request for Quotation (RFQ) for STM704RM6E 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 STM704RM6E reliable?
The price and inventory of STM704RM6E are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STM704RM6E is usually 5 days.
3.What payment methods are accepted for STM704RM6E?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STM704RM6E transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STM704RM6E?
STM704RM6E orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STM704RM6E 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 STM704RM6E?
For technical support, including STM704RM6E datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STM704RM6E requirements.
6.How does Aetrix verify that STM704RM6E is sourced from the original manufacturer or authorized distributors?
All STM704RM6E 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 STM704RM6E meets industry standards.
7.What is the process for return or replacement of STM704RM6E?
All STM704RM6E units undergo pre-shipment inspection (PSI). If there is an issue with STM704RM6E, 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 STM704RM6E part is unused and in its original packaging.
Return procedure for STM704RM6E:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
STM704RM6E Tags
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MIC826SYMT-TR
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