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STMicroelectronics STM819MM6E
- Part No.:
- STM819MM6E
- Manufacturer:
- STMicroelectronics
- Category:
- Supervisors
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
STM819MM6E.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8SO
- Quantity:
- Payment:
- Shipping:
Inventory:2,341
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Product details
Overview
STM819MM6E from STMicroelectronics is a 5 V microprocessor supervisory IC with battery switchover, active-low and active-high reset outputs, manual reset input (MR), power-fail comparator (PFI/PFO), and battery freshness seal - designed for non-volatile SRAM backup in industrial embedded systems. It guarantees RST assertion down to VCC = 1.0 V, features 200 ms typical reset timeout (trec), and draws only 40 µA typical supply current.
For engineers reviewing the STM819MM6E datasheet, STM819MM6E pinout, STM819MM6E application, or STM819MM6E equivalent, key selection criteria include dual-reset polarity support, PFI/PFO early power-fail warning, MR-driven manual reset timing, and guaranteed low-VCC reset assertion - all critical for reliable LPSRAM retention during brownout or main power loss.
Technical Context
The STM819MM6E implements a precision voltage monitor with reset threshold VRST ≈ 4.63 V (typ) and switchover voltage VSO = min(VBAT, VRST), enabling seamless VCC-to-VBAT transition for external LPSRAM. Its dual push-pull RST/RST outputs are asserted simultaneously on VCC drop, MR low, or power-fail detection - with trec = 200 ms (typ) ensuring sufficient MCU initialization time.
Unlike watchdog-equipped variants (e.g., STM817), the STM819 lacks WDI functionality but includes dedicated MR input with internal 40 kΩ pull-up and noise-immunity support via optional 0.1 µF capacitor. The PFI/PFO pair provides programmable power-fail warning at VPFI = 2.4 V (typ), independent of VCC level, and operates with push-pull output drive.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply voltage | 5 V nominal; supports full operation across VCC = 1.0 V to 5.5 V - ensures reset validity during deep brownout. |
| Reset threshold (VRST) | 4.63 V (typ); precise trip point for detecting VCC undervoltage - guarantees deterministic reset initiation. |
| Reset timeout (trec) | 200 ms (typ); fixed internal timer duration after VCC recovery or MR release - meets common MCU boot timing requirements. |
| Power-fail threshold (VPFI) | 2.4 V (typ); independent comparator reference for early warning before VCC drops below VRST - enables graceful shutdown. |
| Battery supply current | 0.4 µA (typ); ultra-low quiescent draw in VBAT-backup mode - extends coin-cell life beyond 10 years. |
| Operating temperature | –40 °C to +85 °C; industrial-grade rating - validated for use in harsh environments without derating. |
| Package | SO8 (Small Outline, 8-pin); standard surface-mount footprint compatible with automated assembly and IPC-7351B land patterns. |
Pinout & Package
STM819MM6E is housed in an 8-pin SO8 package (body width 3.9 mm, lead pitch 1.27 mm), per STMicroelectronics mechanical drawing DocID10522 Rev 11 Section 6.1. Pin functions are validated per Table 3 and Figures 5 & 8 of the datasheet.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VCC | Main supply input | Primary 5 V rail connection; powers internal circuitry and feeds VOUT when above VSO. |
| VBAT | Backup battery input | Connects to coin cell or supercap; automatically supplies VOUT when VCC falls below VSO. |
| VOUT | LPSRAM supply output | Switched output delivering either VCC or VBAT - maintains continuous power to external low-power SRAM. |
| RST | Active-low reset output | Push-pull output asserted low during fault conditions; directly interfaces with MCU reset pin requiring active-low assertion. |
| RST | Active-high reset output | Push-pull output asserted high during same fault conditions; supports MCUs with active-high reset inputs. |
| MR | Manual reset input | Active-low input with internal 40 kΩ pull-up; initiates reset on logic low - enables hardware reset button without external components. |
| PFI | Power-fail input | Analog input monitoring system voltage; triggers PFO low when VPFI < 2.4 V - provides early warning prior to VCC collapse. |
| PFO | Power-fail output | Push-pull output driven low when PFI < VPFI or VCC < 2.4 V; signals impending power loss to host controller or PMIC. |
Key Features
| Feature | Design Value |
|---|---|
| Dual-polarity reset outputs | RST (active-low) and RST (active-high) both asserted simultaneously - eliminates need for external inverters in mixed-reset-interface systems. |
| Automatic battery switchover | VOUT switches from VCC to VBAT at VSO = min(VBAT, VRST) - maximizes main supply usage and extends backup runtime. |
| Battery freshness seal | Internal circuit prevents VBAT discharge during storage until first VCC power-up - preserves shelf life of primary lithium cells. |
| Power-fail comparator (PFI/PFO) | Independent 2.4 V threshold with push-pull PFO - delivers fast, noise-immune early warning without external comparators or pull-ups. |
| Guaranteed reset down to 1.0 V | RST remains valid even as VCC collapses to 1.0 V (no battery) - ensures last-chance reset assertion before MCU lockup. |
Applications
| Industrial PLC Memory Backup | Medical Device Data Retention |
|---|---|
|
Use Scenario: Maintaining configuration and calibration data in programmable logic controllers during AC mains interruption. IC Role / Device Role / Timing Role: Supervisory IC providing VOUT switchover to coin-cell-backed LPSRAM and asserting dual RST signals to halt PLC CPU execution. Use Value: Prevents loss of I/O mapping and PID tuning parameters during 200 ms trec window - enabling immediate resumption post-recovery. |
Use Scenario: Preserving patient therapy settings and sensor calibration history in portable infusion pumps during battery swap. IC Role / Device Role / Timing Role: Battery switchover controller and reset supervisor ensuring uninterrupted SRAM power and safe CPU reset sequencing. Use Value: 0.4 µA VBAT current extends CR2032 life >12 years; freshness seal prevents pre-deployment discharge - meeting IEC 62304 Class C requirements. |
| Smart Meter Firmware Integrity | Automotive Telematics Logging |
|
Use Scenario: Securing firmware update state and tariff tables in electricity meters subjected to grid instability. IC Role / Device Role / Timing Role: Power-fail detector (PFI/PFO) and reset generator coordinating EEPROM write abort and SRAM freeze on brownout. Use Value: VPFI = 2.4 V triggers PFO 200+ ms before VRST breach - allowing time to complete critical flash writes before VCC collapse. |
Use Scenario: Capturing crash event data in vehicle telematics units during ignition cycling or alternator failure. IC Role / Device Role / Timing Role: Dual-reset supervisor asserting RST/RST to freeze CAN controller and trigger SRAM-to-EEPROM dump on VCC dropout. Use Value: Guaranteed RST assertion down to VCC = 1.0 V ensures CPU reset completes even during severe battery sag - preserving forensic logs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| STM817MM6F | Includes watchdog timer (WDI); no MR input; identical PFI/PFO, RST/RST, and battery switchover. | Requires periodic WDI toggling; unsuitable where manual reset is mandatory or watchdog adds complexity. | Select when system-level software watchdog supervision is required and MR is unused. |
| MAX692CPA+ | Single active-low RST; no RST output; no PFI/PFO; higher 10 µA VBAT current; same SO8 package. | Lacks dual-reset polarity and early power-fail warning - limits use to basic reset-only designs. | Select only if dual-reset and PFI/PFO are unnecessary and legacy MAXIM compatibility is prioritized. |
Compared with STM817MM6F and MAX692CPA+, the STM819MM6E uniquely combines MR-driven manual reset, dual-polarity reset outputs, and integrated PFI/PFO - making it optimal for systems requiring field-serviceable reset, multi-MCU interface flexibility, and deterministic power-fail response without software overhead.
Availability
STM819MM6E is available at Aetrix Electronics and suitable for industrial PLC memory backup, medical device data retention, smart meter firmware integrity, and automotive telematics logging requiring stable component supply across extended product lifecycles.
Supply support for STM819MM6E 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 sensing solutions for industrial, automotive, and consumer markets.
The STM8xx supervisor family targets robust, low-power system management in space-constrained embedded applications - emphasizing reliability, battery longevity, and seamless integration with external LPSRAM and microprocessors.
FAQ
Does STM819MM6E support watchdog functionality?
No. Unlike STM817/818, the STM819MM6E omits the watchdog timer (WDI pin) and related circuitry. Its reset generation relies solely on VCC monitoring, MR input, and PFI-triggered power-fail detection. This simplifies design where software-level watchdog supervision is handled externally or not required.
What is the purpose of the battery freshness seal in STM819MM6E?
The battery freshness seal prevents VBAT discharge during storage by disabling the internal switchover path until VCC is first applied and exceeds VRST. This preserves coin-cell capacity for field use - critical for long-shelf-life devices like utility meters and medical implants where pre-deployment battery drain must be avoided.
Can VBAT exceed VCC in STM819MM6E operation?
Yes. VBAT may be up to 5.5 V regardless of VCC level. When VCC falls below VSO = min(VBAT, VRST), VOUT connects to VBAT through a 100 Ω internal switch. This allows use of higher-voltage backup sources (e.g., 3.6 V LiSOCl₂) while maintaining compatibility with 5 V main rails.
How does the PFI/PFO function interact with VCC monitoring?
PFI/PFO operates independently of the main reset comparator: PFO asserts low when PFI < 2.4 V (typ) OR when VCC falls below 2.4 V - providing early warning before VCC reaches the 4.63 V reset threshold. This dual-trigger behavior enables proactive system shutdown or data save operations prior to reset assertion.
STM819MM6E 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:
- 4.4V
- 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
STM819MM6E FAQ
1.How can I place an order for STM819MM6E through Aetrix?
Please submit a Request for Quotation (RFQ) for STM819MM6E 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 STM819MM6E reliable?
The price and inventory of STM819MM6E are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STM819MM6E is usually 5 days.
3.What payment methods are accepted for STM819MM6E?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STM819MM6E transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STM819MM6E?
STM819MM6E orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STM819MM6E 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 STM819MM6E?
For technical support, including STM819MM6E datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STM819MM6E requirements.
6.How does Aetrix verify that STM819MM6E is sourced from the original manufacturer or authorized distributors?
All STM819MM6E 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 STM819MM6E meets industry standards.
7.What is the process for return or replacement of STM819MM6E?
All STM819MM6E units undergo pre-shipment inspection (PSI). If there is an issue with STM819MM6E, 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 STM819MM6E part is unused and in its original packaging.
Return procedure for STM819MM6E:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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