My Inquiry
My Account
STMicroelectronics STM805TM6F
- Part No.:
- STM805TM6F
- Manufacturer:
- STMicroelectronics
- Category:
- Supervisors
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
STM805TM6F.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:117
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
STM805TM6F from STMicroelectronics is a 3 V industrial-grade microprocessor supervisory IC with active-high open-drain RST output, automatic battery switchover (VCC to VBAT), power-fail comparator (PFI/PFO), and manual reset input (MR). It guarantees reset assertion down to VCC = 1.0 V, features 200 ms typical reset timeout (trec), and draws only 40 µA typical supply current - designed for non-volatile SRAM backup in embedded control systems.
For engineers reviewing the STM805TM6F datasheet, STM805TM6F pinout, STM805TM6F application, or STM805TM6F equivalent, key selection criteria include its open-drain RST output logic, battery switchover threshold (VSW = 2.4 V), PFI comparator reference (VPFI = 1.25 V), and compatibility with external LPSRAM retention during main power loss.
Technical Context
The STM805TM6F integrates a precision voltage reference, dual comparators (for VCC monitoring and PFI detection), and an internal trec timer that ensures minimum 200 ms reset pulse width after power-up, brownout recovery, or MR release. Its reset output is active-high and open-drain - requiring an external pull-up - enabling direct interface with microcontrollers accepting high-active reset signals.
Battery switchover is managed by a P-channel MOSFET switch connecting VBAT to VOUT when VCC falls below 2.4 V; Vccsw provides a push-pull indicator signal for external PMOS gate control. The device lacks watchdog functionality (not present on STM805) and chip enable gating (exclusive to STM795), distinguishing it from other family members.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| RST Output Type | Active-high, open-drain - requires external pull-up; compatible with high-active MCU reset inputs. |
| Reset Threshold (VRST) | 2.63 V (typ) - asserts RST when VCC drops below this level; guaranteed operation down to VCC = 1.0 V. |
| Reset Timeout (trec) | 200 ms (typ) - minimum duration RST remains asserted after VCC rise, MR release, or fault recovery. |
| Battery Switchover Voltage (VSW) | 2.4 V - triggers automatic VOUT sourcing from VBAT when VCC falls below this threshold. |
| Power-Fail Input Threshold (VPFI) | 1.25 V - PFO goes low when PFI < 1.25 V, enabling early warning of supply collapse. |
| Supply Current (ICC) | 40 µA (typ) - ultra-low quiescent current during normal VCC operation, minimizing system power overhead. |
| Battery Supply Current (IBAT) | 0.4 µA (typ) - minimal drain on backup battery during VBAT-only operation, extending hold-up time. |
Pinout & Package
STM805TM6F is housed in an 8-pin SO8 (Small Outline Integrated Circuit) package, compliant with JEDEC MS-012, with 1.27 mm pitch and surface-mount footprint. Pin numbering follows standard SO8 convention (pin 1 at top-left corner, counterclockwise).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1: PFO | Power-fail output | Push-pull output asserting low when PFI < 1.25 V or VCC < 2.4 V; used for system-level power-fail interrupt signaling. |
| 2: VOUT | Supply output voltage | Switched output sourcing from VCC (when VCC > 2.4 V) or VBAT (when VCC ≤ 2.4 V); powers external LPSRAM. |
| 3: VCC | Main supply input | Primary 3 V system rail input; monitored for reset generation and switchover control. |
| 4: RST | Active-high reset output | Open-drain output pulled high externally; drives MCU reset pin high during fault or power-up sequence. |
| 5: VSS | Ground | System ground reference for all internal comparators, timers, and I/O circuits. |
| 6: MR | Manual reset input | Active-low input with internal 40 kΩ pull-up; initiates reset when shorted to GND via push-button. |
| 7: PFI | Power-fail input | Analog input monitoring auxiliary supply or divided VCC; triggers PFO when voltage drops below 1.25 V. |
| 8: VBAT | Backup battery input | Input for lithium or coin-cell backup source; automatically engages when VCC fails, sustaining VOUT and SRAM. |
Key Features
| Feature | Design Value |
|---|---|
| Guaranteed reset down to 1.0 V VCC | Ensures reliable MCU reset even during deep brownout conditions without battery support. |
| Automatic VCC/VBAT switchover at 2.4 V | Seamlessly transfers VOUT supply to backup battery within microseconds of VCC collapse, preserving SRAM data. |
| Open-drain RST with external pull-up | Enables flexible voltage-level translation and wired-OR reset bus configurations across mixed-voltage systems. |
| Integrated power-fail comparator (PFI/PFO) | Provides programmable early-warning interrupt before VCC reaches reset threshold, allowing graceful shutdown. |
| Low 40 µA operating current | Minimizes impact on primary 3 V rail in always-on or low-power embedded applications. |
Applications
| Industrial PLC Controller | Smart Meter Data Retention |
|---|---|
|
Use Scenario: Maintaining real-time energy logging during grid voltage sags or outages. IC Role / Device Role / Timing Role: Supervisory IC providing battery-backed VOUT to LPSRAM and generating PFO interrupt for firmware-initiated data save prior to power loss. Use Value: Enables deterministic 200 ms reset window and sub-1 V reset guarantee, ensuring no metering data corruption during transient brownouts. |
Use Scenario: Preserving tariff configuration and consumption history in AMI meters during utility power interruption. IC Role / Device Role / Timing Role: Automatic VCC-to-VBAT switchover at 2.4 V with 0.4 µA battery drain, sustaining SRAM for >10 years on CR2032. Use Value: Eliminates need for external switchover circuitry while meeting IEC 62053-21 data retention requirements under extended outage conditions. |
| Medical Infusion Pump Memory | Factory Automation HMI Backup |
|
Use Scenario: Securing dose history and calibration parameters during unexpected AC power loss. IC Role / Device Role / Timing Role: Active-high open-drain RST synchronizes with pump MCU's high-active reset input; PFI monitors isolated DC/DC output for predictive shutdown. Use Value: Meets IEC 62304 Class B safety requirements via guaranteed 1.0 V reset assertion and 200 ms trec timing margin. |
Use Scenario: Retaining operator session state and alarm logs on human-machine interface panels during factory line power dips. IC Role / Device Role / Timing Role: VOUT powers 256 KB LPSRAM; Vccsw signal enables external PMOS switch for >75 mA backup current capability. Use Value: Supports fast switchover (<10 µs) and sustained 3.3 V SRAM bias during 100 ms–2 s interruptions common in industrial environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar supervisor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| STM804TM6F | Identical pinout and function, but RST is active-high open-drain with same 2.63 V threshold and 200 ms trec - no functional difference from STM805TM6F. | No application difference; both target 3 V LPSRAM backup with PFI/PFO and MR. | Select STM804TM6F only if legacy BOM references that part number; electrically interchangeable with STM805TM6F. |
| MAX809TRD2T | Single-supply 3 V reset IC with active-high push-pull RST (not open-drain), 2.93 V reset threshold, no PFI/PFO or battery switchover. | Limited to basic reset generation; cannot support SRAM backup or power-fail warning functions. | Choose only for simple reset-only applications where battery backup and early power-fail detection are unnecessary. |
Compared with STM805TM6F, STM804TM6F offers identical functionality and drop-in compatibility, whereas MAX809TRD2T omits critical features like battery switchover and PFI monitoring - making it suitable only for basic reset supervision without data retention requirements.
Availability
STM805TM6F is available at Aetrix Electronics and suitable for industrial PLC controllers, smart meter data retention, medical infusion pump memory, and factory automation HMI backup requiring stable component supply and long-term lifecycle support.
Supply support for STM805TM6F 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 STM690/80x supervisor family was developed specifically for robust, low-power microprocessor supervision with integrated battery switchover and non-volatile SRAM support in space-constrained industrial applications.
FAQ
Is STM805TM6F pin-compatible with STM804TM6F?
Yes - STM805TM6F and STM804TM6F share identical SO8 pinout, electrical specifications, and functional behavior including active-high open-drain RST, 2.63 V reset threshold, 200 ms trec, and full PFI/PFO + MR + VBAT support. They are functionally and physically interchangeable in all designs.
What is the maximum load current supported on VOUT during battery backup?
VOUT supports up to 75 mA when sourced from VBAT via the internal 100 Ω P-channel MOSFET switch. For higher currents, use Vccsw (pin 4) to drive an external PMOS transistor - the datasheet confirms Vccsw is a push-pull output capable of directly controlling gate voltage.
Does STM805TM6F include a watchdog timer?
No - the STM805TM6F does not include a watchdog timer. Per ST's official datasheet (DocID10519 Rev 10, Section 2.3), watchdog functionality is explicitly excluded from STM805 and is only available on STM690, STM802, STM804, and STM806 variants.
Can PFI be left unconnected if power-fail detection is not needed?
Yes - PFI must be connected to ground if unused, as stated in Section 1.1.5 of the datasheet. Leaving it floating may cause unpredictable PFO behavior due to noise sensitivity; grounding ensures PFO remains high (inactive) and avoids false power-fail assertions.
STM805TM6F 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:
- 3.075V
- Output:
- Open Drain or Open Collector
- Reset:
- Active High
- Reset Timeout:
- 140ms Minimum
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
STM805TM6F FAQ
1.How can I place an order for STM805TM6F through Aetrix?
Please submit a Request for Quotation (RFQ) for STM805TM6F 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 STM805TM6F reliable?
The price and inventory of STM805TM6F are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STM805TM6F is usually 5 days.
3.What payment methods are accepted for STM805TM6F?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STM805TM6F transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STM805TM6F?
STM805TM6F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STM805TM6F 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 STM805TM6F?
For technical support, including STM805TM6F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STM805TM6F requirements.
6.How does Aetrix verify that STM805TM6F is sourced from the original manufacturer or authorized distributors?
All STM805TM6F 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 STM805TM6F meets industry standards.
7.What is the process for return or replacement of STM805TM6F?
All STM805TM6F units undergo pre-shipment inspection (PSI). If there is an issue with STM805TM6F, 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 STM805TM6F part is unused and in its original packaging.
Return procedure for STM805TM6F:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
STM805TM6F 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…
