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STMicroelectronics STM690RM6F
- Part No.:
- STM690RM6F
- Manufacturer:
- STMicroelectronics
- Category:
- Supervisors
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
STM690RM6F.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,045
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Product details
Overview
STM690RM6F from STMicroelectronics is a 3 V industrial-grade microprocessor supervisor IC with integrated battery switchover, active-low push-pull RST output, manual reset (MR) input, watchdog timer (1.6 s typ), and power-fail comparator (PFI/PFO). It guarantees RST assertion down to VCC = 1.0 V and supports external LPSRAM non-volatilization in embedded systems requiring reliable power monitoring and backup switching.
For engineers reviewing the STM690RM6F datasheet, STM690RM6F pinout, STM690RM6F application, or STM690RM6F equivalent, key selection criteria include guaranteed reset assertion at 1.0 V VCC, 200 ms typical reset timeout (trec), 0.4 µA typical battery supply current, push-pull RST output configuration, and SO8 package compatibility for space-constrained industrial control and metering designs.
Technical Context
The STM690RM6F implements a precision voltage reference and comparator to monitor VCC against a fixed reset threshold (VRST ≈ 2.63 V), asserting RST when VCC falls below VRST or during MR activation. Its internal trec generator ensures minimum 200 ms reset pulse width after power-up or fault recovery.
It integrates an automatic battery switchover circuit that connects VBAT to VOUT when VCC drops below VSW = 2.4 V, using a P-channel MOSFET switch with 100 Ω on-resistance. The watchdog timer monitors WDI activity with 1.6 s timeout and clears on any edge transition - not float - ensuring robust MCU supervision.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold (VRST) | 2.63 V ±1.5% - ensures reliable MCU reset initiation before brownout affects core logic |
| Reset Timeout (trec) | 200 ms typ - provides sufficient hold time for full system initialization and memory stabilization |
| Watchdog Timeout (tWD) | 1.6 s typ - detects stalled firmware execution without requiring software intervention |
| Battery Supply Current | 0.4 µA typ - enables multi-year operation on coin-cell backup without significant drain |
| Operating Temperature | –40 °C to +85 °C - qualified for industrial environments including smart meters and PLCs |
| Power-Fail Comparator Threshold | VPFI = 1.25 V ±3% - triggers early warning before VCC collapse reaches critical levels |
| VCC Switchover Voltage (VSW) | 2.4 V - initiates seamless LPSRAM backup before main supply fails completely |
Pinout & Package
STM690RM6F is housed in an 8-pin SO8 (Small Outline) package per JEDEC MS-012, with 1.27 mm pitch and surface-mount footprint. 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; drives interrupt or flag logic directly |
| 2: VOUT | Supply output for LPSRAM | Switched output connected to VCC or VBAT; powers external low-power SRAM during main supply loss |
| 3: VCC | Main supply input | Primary 3 V system rail; monitored for reset threshold violation and switchover control |
| 4: RST | Active-low reset output | Push-pull output asserted low during fault, MR press, or watchdog timeout; resets MCU reliably |
| 5: VSS | Ground reference | Common return path for all internal circuits and external decoupling capacitors |
| 6: MR | Manual reset input | Active-low input with internal 40 kΩ pull-up; enables hardware-initiated reset without external components |
| 7: WDI | Watchdog input | Edge-sensitive input; toggling within 1.6 s prevents reset; floating causes timeout |
| 8: PFI | Power-fail input | Monitors auxiliary rail or scaled VCC; asserts PFO when voltage drops below 1.25 V |
Key Features
| Feature | Design Value |
|---|---|
| Guaranteed RST assertion at VCC = 1.0 V | Ensures reset remains valid even during deep brownout, protecting MCU state integrity |
| Automatic battery switchover with VCC/VBAT priority logic | Enables zero-interruption LPSRAM backup without external FETs or control logic |
| Integrated 1.6 s watchdog timer with edge-triggered clear | Eliminates need for external timing components while preventing false timeouts from noise |
| Low 40 µA typical supply current (VCC mode) | Reduces system-level power budget impact in always-on monitoring applications |
| Push-pull RST and PFO outputs | Drives standard CMOS/TTL inputs directly without pull-up resistors or level-shifting |
Applications
| Smart Energy Metering | Industrial PLC I/O Modules |
|---|---|
|
Use Scenario: Maintaining SRAM data during utility grid interruptions or battery replacement. IC Role / Device Role / Timing Role: Supervisor IC providing VOUT switchover, RST assertion, and PFO early-warning signal. Use Value: Preserves meter calibration constants and last-read values for >10 years on CR2032 via 0.4 µA battery draw. |
Use Scenario: Ensuring deterministic restart after power glitches in factory automation controllers. IC Role / Device Role / Timing Role: Reset generator with 200 ms trec and 1.6 s watchdog, interfacing to ARM Cortex-M7 MCU. Use Value: Prevents corrupted I/O state by guaranteeing full peripheral reinitialization before application code resumes. |
| Medical Infusion Pump Control | Building Automation Gateway |
|
Use Scenario: Safeguarding therapy parameters stored in external LPSRAM during AC/DC adapter failure. IC Role / Device Role / Timing Role: Dual-role supervisor: reset source and battery-backed SRAM power manager. Use Value: Meets IEC 62304 Class C requirements via guaranteed 1.0 V RST assertion and fail-safe switchover. |
Use Scenario: Supporting firmware updates and configuration retention across intermittent PoE power cycles. IC Role / Device Role / Timing Role: Power-fail detector (PFI/PFO) and manual reset enabler (MR) for field-service recovery. Use Value: Enables safe OTA update rollback using PFO-triggered NMI and MR-initiated factory reset. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX690TSA+ | Higher reset threshold (3.08 V), no watchdog timer, 10 µA VCC supply current | Lacks battery switchover and watchdog; suited only for basic reset-only use cases | Select when design requires higher VCC trip point and no backup SRAM support |
| TPS3808G18DBVR | Adjustable reset threshold (via resistor divider), 350 ms min trec, no PFI/PFO or battery switchover | Requires external components for power-fail detection; no integrated VOUT switching | Choose when precise threshold tuning is needed and battery backup is handled separately |
Compared with MAX690TSA+ and TPS3808G18DBVR, STM690RM6F uniquely combines guaranteed 1.0 V reset assertion, integrated battery switchover, watchdog, and power-fail comparator in a single SO8 package - eliminating four discrete functions required by alternatives.
Availability
STM690RM6F is available at Aetrix Electronics and suitable for smart energy metering, industrial PLC I/O modules, medical infusion pump control, and building automation gateway designs requiring stable component supply, long-lifecycle assurance, and RoHS-compliant sourcing.
Supply support for STM690RM6F 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.
STM690 belongs to ST's legacy supervisor IC product line, engineered specifically for robust power monitoring and non-volatile SRAM support in cost-sensitive, high-reliability industrial systems.
FAQ
What is the function of the Vccsw pin on STM690RM6F?
Vccsw is a push-pull output that goes high when VOUT switches to VBAT (i.e., during main supply failure) and low when VOUT reconnects to VCC. It is designed to drive the gate of an external PMOS transistor to extend IOUT beyond the internal 75 mA limit, enabling higher-current backup for larger SRAM arrays or real-time clocks.
Can STM690RM6F operate without a backup battery?
Yes. When no battery is used, VBAT and VOUT must both be connected to VCC. In this configuration, the device functions as a standard 3 V supervisor with RST, MR, WDI, and PFI/PFO - retaining full reset generation, watchdog, and power-fail detection capabilities without battery switchover.
Is the watchdog timer on STM690RM6F disableable?
No. The watchdog timer cannot be disabled; it is always active when VCC is powered. Leaving WDI floating causes continuous timeout and reset assertion every ~1.8 s (tWD + trec). To prevent unintended resets, WDI must be actively toggled or tied to a controlled logic signal that meets the 1.6 s timeout window.
How does STM690RM6F handle negative-going VCC transients?
The device incorporates transient immunity circuitry that ignores short-duration VCC dips (<100 ns) below VRST. As confirmed in Section 2.11 of the datasheet, reset is not triggered unless the VCC drop exceeds both amplitude and duration thresholds - preventing spurious resets from ESD or switching noise in noisy industrial environments.
STM690RM6F 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
STM690RM6F FAQ
1.How can I place an order for STM690RM6F through Aetrix?
Please submit a Request for Quotation (RFQ) for STM690RM6F 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 STM690RM6F reliable?
The price and inventory of STM690RM6F are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STM690RM6F is usually 5 days.
3.What payment methods are accepted for STM690RM6F?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STM690RM6F transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STM690RM6F?
STM690RM6F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STM690RM6F 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 STM690RM6F?
For technical support, including STM690RM6F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STM690RM6F requirements.
6.How does Aetrix verify that STM690RM6F is sourced from the original manufacturer or authorized distributors?
All STM690RM6F 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 STM690RM6F meets industry standards.
7.What is the process for return or replacement of STM690RM6F?
All STM690RM6F units undergo pre-shipment inspection (PSI). If there is an issue with STM690RM6F, 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 STM690RM6F part is unused and in its original packaging.
Return procedure for STM690RM6F:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
STM690RM6F Tags
-
MIC826SYMT-TR
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