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STMicroelectronics STM690AM6E
- Part No.:
- STM690AM6E
- Manufacturer:
- STMicroelectronics
- Category:
- Supervisors
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
STM690AM6E.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8SO
- Quantity:
- Payment:
- Shipping:
Inventory:4,092
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Product details
Overview
STM690AM6E from STMicroelectronics is a 5 V microprocessor supervisory IC with battery switchover, NVRAM supervision for external LPSRAM, dual active-low and active-high reset outputs (RST/RST), and a 1.6 s watchdog timer. It guarantees RST assertion down to VCC = 1.0 V, features 200 ms typical reset timeout (trec), and supports automatic power-fail detection via PFI/PFO comparator - used in industrial embedded systems requiring nonvolatile SRAM retention during main supply loss.
For engineers reviewing the STM690AM6E datasheet, STM690AM6E pinout, STM690AM6E application, or STM690AM6E equivalent, key selection criteria include guaranteed reset assertion at low VCC, battery switchover behavior, push-pull RST/RST timing, watchdog timeout stability over temperature, and compatibility with LPSRAM enable gating in legacy 5 V systems.
Technical Context
The STM690AM6E integrates a precision voltage reference and comparator monitoring VCC against a fixed reset threshold (VRST ≈ 4.63 V), triggering RST/RST assertion on undervoltage, watchdog timeout, or manual reset (MR). Its internal P-channel MOSFET switch enables seamless VOUT switchover from VCC to VBAT when VCC falls below the lesser of VRST or VBAT (VSO), with 100 Ω on-resistance and 0.4 µA typical battery current.
It implements a 1.6 s typ watchdog timer cleared by WDI edge transitions (≥50 ns), disabled when WDI floats. All RST and RST outputs are push-pull; PFI/PFO provides early power-fail warning with VPFI = 2.4 V threshold and 1.5 µs typ propagation delay. No chip-enable gating (E/ECON) or battery freshness seal is present - distinguishing it from STM817/818/819 variants.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC operating range | 4.75 V to 5.5 V - ensures compatibility with standard 5 V logic rails and tolerates ±5% supply variation. |
| Reset threshold (VRST) | 4.63 V (typ) - triggers RST/RST assertion before MCU brownout, with hysteresis preventing chatter near threshold. |
| Reset timeout (trec) | 200 ms (typ) - guarantees minimum reset pulse width for reliable processor initialization after power-up or fault recovery. |
| Watchdog timeout (tWD) | 1.6 s (typ) - detects MCU lockup with sufficient margin to cover longest firmware task cycles in industrial control. |
| Battery supply current | 0.4 µA (typ) - minimizes backup battery drain during extended VCC loss, enabling >10-year coin-cell operation. |
| Power-fail threshold (VPFI) | 2.4 V - asserts PFO before VCC drops below critical LPSRAM retention voltage, enabling graceful data save. |
| Operating temperature | –40 °C to +85 °C - qualified for industrial-grade environments without derating. |
Pinout & Package
STM690AM6E is housed in an 8-pin SO8 (Small Outline) package per JEDEC MS-012, with 1.27 mm pitch, gull-wing leads, and body dimensions 4.9 mm × 6.0 mm × 1.75 mm. Pin 1 marked by notch or dot; recommended PCB footprint per Table 8 in DocID10522 Rev 11.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1: RST | Active-high reset output | Push-pull output asserted high during reset condition; compatible with MCUs requiring active-high reset input. |
| 2: VOUT | SRAM supply output | Switched output connected to VCC or VBAT; powers external LPSRAM during main supply failure. |
| 3: PFO | Power-fail output | Push-pull signal goes low when PFI < 2.4 V or VCC < VSO - used to trigger system shutdown or data save. |
| 4: VBAT | Backup battery input | Accepts 2.0–5.5 V battery; automatically selected as VOUT source when VCC drops below switchover voltage. |
| 5: PFI | Power-fail input | Monitors auxiliary rail (e.g., 3.3 V domain); asserts PFO when voltage falls below 2.4 V threshold. |
| 6: MR | Manual reset input | Active-low input with internal 40 kΩ pull-up; debounced by trec timer - no external RC needed. |
| 7: WDI | Watchdog input | Edge-sensitive (rising/falling ≥50 ns); clears watchdog timer - prevents false timeout during normal MCU operation. |
| 8: VCC | Main supply input | 5 V nominal input; powers internal circuitry and feeds VOUT when above VSO; monitored for reset generation. |
Key Features
| Feature | Design Value |
|---|---|
| Dual reset outputs | RST (active-low) and RST (active-high) both push-pull - eliminates need for external inverters in mixed-logic systems. |
| Guaranteed reset at low VCC | RST asserted down to VCC = 1.0 V (no battery) or 0 V < VCC < VRST (with VBAT > 1 V) - ensures fail-safe reset under severe brownout. |
| Low battery drain | 0.4 µA typical VBAT current - extends CR2032 life to >12 years in standby, critical for unattended remote nodes. |
| Automatic battery switchover | VOUT switches from VCC to VBAT at VSO = min(VRST, VBAT) with 100 Ω on-resistance - preserves LPSRAM data without software intervention. |
| Integrated power-fail comparator | PFI/PFO pair with 2.4 V threshold and 1.5 µs propagation delay - enables deterministic pre-failure warning for controlled shutdown. |
Applications
| Industrial PLC Memory Backup | Medical Device Data Retention |
|---|---|
Use Scenario: Programmable logic controller retains configuration and runtime variables in external LPSRAM during AC mains interruption. IC Role / Device Role / Timing Role: STM690AM6E monitors 5 V rail, asserts RST to halt CPU, switches VOUT to coin-cell battery, and signals PFO to initiate EEPROM save before power loss. Use Value: Enables zero-data-loss recovery after 500 ms outage; 0.4 µA battery current supports >10-year shelf life with CR2032. | Use Scenario: Portable infusion pump stores therapy logs and calibration data in LPSRAM across battery swaps and charging cycles. IC Role / Device Role / Timing Role: Provides VCC brownout detection (4.63 V threshold), generates 200 ms RST pulse for safe MCU shutdown, and maintains VOUT from backup cell during transition. Use Value: Guarantees RST assertion even at VCC = 1.0 V - prevents corrupted memory writes during deep discharge events. |
| Telecom Remote Terminal | Energy Meter Firmware Protection |
Use Scenario: Cellular backhaul unit sustains real-time clock and configuration SRAM during 48 V DC supply dips caused by lightning surges. IC Role / Device Role / Timing Role: Uses PFI to monitor regulated 3.3 V rail; asserts PFO 200 µs before VCC dropout, triggering watchdog-initiated save sequence. Use Value: 2.4 V PFI threshold aligns with LPSRAM retention voltage; 1.5 µs PFO response ensures timely interrupt before data corruption. | Use Scenario: Smart electricity meter preserves tariff tables and consumption history in LPSRAM during grid outages lasting minutes to hours. IC Role / Device Role / Timing Role: Supervises 5 V microcontroller supply, asserts RST on undervoltage, and gates VOUT to backup supercapacitor via internal MOSFET switch. Use Value: 100 Ω VOUT switch resistance limits voltage drop under 10 mA LPSRAM load - maintains >2.7 V SRAM hold level during switchover. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar supervisor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX690AESA+ | Same 5 V operation, 4.65 V reset threshold, 200 ms trec, but lacks PFI/PFO and battery switchover - only provides basic reset + watchdog. | No VOUT switchover or PFO warning; requires external diode-OR for battery backup. | Select when LPSRAM supervision is unnecessary and cost reduction is prioritized over power-fail signaling. |
| TPS3823MPW | 3.3 V only (not 5 V), 2.93 V reset threshold, 200 ms trec, includes watchdog and manual reset - no battery switchover or PFI/PFO. | Not pin-compatible; requires level-shifting for 5 V systems; unsuitable for LPSRAM backup. | Choose only for new 3.3 V designs where ST's 5 V ecosystem integration is not required. |
Compared with MAX690AESA+ and TPS3823MPW, STM690AM6E uniquely combines 5 V supervision, dual reset polarity, battery switchover, and power-fail warning in one SO8 package - making it irreplaceable for legacy industrial systems relying on external LPSRAM retention.
Availability
STM690AM6E is available at Aetrix Electronics and suitable for industrial PLCs, medical data loggers, telecom remote terminals, and smart energy meters requiring stable component supply with long-term lifecycle support.
Supply support for STM690AM6E 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 automotive, industrial, and consumer markets.
The STM690A series belongs to ST's legacy microprocessor supervisor product line, engineered specifically for robust 5 V system monitoring, NVRAM backup, and fail-safe reset generation in harsh industrial environments.
FAQ
What is the function of the VOUT pin on STM690AM6E?
VOUT is the switched output that supplies external LPSRAM. When VCC is above the switchover voltage (VSO = min(VRST, VBAT)), VOUT connects to VCC. When VCC drops below VSO, VOUT automatically connects to VBAT through an internal 100 Ω P-MOSFET switch - preserving SRAM data without software involvement. VOUT must be decoupled with 0.1 µF ceramic capacitor.
Does STM690AM6E support watchdog functionality, and how is it enabled?
Yes, STM690AM6E includes a 1.6 s typical watchdog timer monitored via the WDI pin. The timer resets on any rising or falling edge ≥50 ns; if WDI remains static (high or low) for >1.6 s, RST/RST is asserted. Watchdog is disabled by floating WDI - no external pull-up/down required due to internal leakage limits (≤10 µA) and capacitance tolerance (≤200 pF).
Can STM690AM6E be used without a backup battery?
Yes. When no battery is used, connect VBAT directly to VCC. In this configuration, VOUT remains tied to VCC at all times, and the device functions as a standard 5 V supervisor with RST/RST, MR, WDI, and PFI/PFO. Reset assertion is guaranteed down to VCC = 1.0 V, and battery current specifications do not apply.
How does the power-fail comparator (PFI/PFO) operate independently of VCC monitoring?
PFI is a dedicated input referenced to an internal 2.4 V threshold. When PFI voltage falls below 2.4 V - regardless of VCC status - PFO asserts low within 1.5 µs. This allows monitoring of secondary rails (e.g., 3.3 V or 2.5 V domains) for early warning of cascading failures. PFO is push-pull and can directly drive MCU interrupts without external pull-ups.
STM690AM6E 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:
- 4.65V
- 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
STM690AM6E FAQ
1.How can I place an order for STM690AM6E through Aetrix?
Please submit a Request for Quotation (RFQ) for STM690AM6E 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 STM690AM6E reliable?
The price and inventory of STM690AM6E are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STM690AM6E is usually 5 days.
3.What payment methods are accepted for STM690AM6E?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STM690AM6E transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STM690AM6E?
STM690AM6E orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STM690AM6E 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 STM690AM6E?
For technical support, including STM690AM6E datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STM690AM6E requirements.
6.How does Aetrix verify that STM690AM6E is sourced from the original manufacturer or authorized distributors?
All STM690AM6E 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 STM690AM6E meets industry standards.
7.What is the process for return or replacement of STM690AM6E?
All STM690AM6E units undergo pre-shipment inspection (PSI). If there is an issue with STM690AM6E, 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 STM690AM6E part is unused and in its original packaging.
Return procedure for STM690AM6E:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
STM690AM6E Tags
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MIC826SYMT-TR
Microchip Technology
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APX803S-31SA-7
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APX803L20-29SA-7
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