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STMicroelectronics STM1815SWX7F
- Part No.:
- STM1815SWX7F
- Manufacturer:
- STMicroelectronics
- Category:
- Supervisors
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
STM1815SWX7F.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:7,604
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Product details
Overview
STM1815SWX7F from STMicroelectronics is a low-power, active-low push-pull reset supervisor IC designed to monitor 3.3 V and 3.0 V supply rails in microcontroller-based systems. It asserts a precise reset signal when VCC drops below 3.06 V (typ.), maintains reset for ≥100 ms after recovery, draws only 4 µA typical supply current, and operates across –40 °C to +105 °C - enabling reliable power-up/brownout protection in portable and industrial embedded controllers.
For engineers reviewing the STM1815SWX7F datasheet, STM1815SWX7F pinout, STM1815SWX7F application, or STM1815SWX7F equivalent, key selection criteria include its factory-trimmed 3.06 V threshold, guaranteed reset assertion down to VCC = 1.0 V, SOT23-3 package compatibility with DS181x/MXD181x footprints, and absence of manual reset detect functionality (distinguishing it from STM1813/1818).
Technical Context
The STM1815SWX7F implements a precision voltage reference and comparator to continuously monitor VCC against a fixed 3.06 V (±2.5%) threshold. Its internal reset timer ensures a minimum 100 ms reset pulse width (trec) after VCC rises above threshold, preventing premature MCU release during unstable power conditions.
It features push-pull active-low RST output with rail-to-rail drive capability, valid down to VCC = 1.0 V over full temperature range. The device includes built-in immunity to fast VCC transients and requires no external components for basic reset supervision in 3.3 V/3.0 V systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 3.06 V (typ.), ±2.5% accuracy from –40 °C to +105 °C - ensures consistent brownout detection across temperature without calibration. |
| Reset Pulse Width | ≥100 ms - guarantees sufficient MCU initialization time after power recovery, eliminating race conditions. |
| Supply Current | 4 µA (typ.) at 25 °C - enables multi-year battery operation in always-on monitoring applications. |
| Operating Voltage Range | 1.0 V to 5.5 V - supports valid reset assertion even during deep brownout, down to 1.0 V at full temperature range. |
| Output Type | Active-low push-pull - drives RST directly to GND or VCC without external pull-up, simplifying interface with standard MCU reset inputs. |
| Temperature Range | –40 °C to +105 °C - qualified for automotive under-hood and industrial control environments. |
| Package | SOT23-3 (WX code) - 3-pin surface-mount footprint compatible with DS181x/MXD181x, enabling drop-in replacement in space-constrained designs. |
Pinout & Package
STM1815SWX7F is housed in a 3-pin SOT23-3 (WX) package - a compact, lead-free, RoHS-compliant surface-mount outline measuring 2.9 mm × 1.3 mm × 1.0 mm (max height), optimized for high-density PCB layouts.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - RST | Active-low push-pull reset output | Drives low to assert reset; returns high (to VCC) when VCC is stable - eliminates need for external pull-up resistor. |
| 2 - VCC | Supply voltage input and reset threshold monitor | Power source and sensing node; device monitors this pin to detect undervoltage - must be connected to the monitored 3.3 V/3.0 V rail. |
| 3 - VSS | Ground reference | System ground return path for internal comparator and output stage - must be tied directly to PCB ground plane for noise immunity. |
Key Features
| Feature | Design Value |
|---|---|
| Precision 3.06 V threshold | Factory-trimmed ±2.5% accuracy over –40 °C to +105 °C - eliminates external resistor networks and reduces BOM count. |
| 100 ms minimum reset timeout | Internally generated delay ensures MCU reset remains asserted long enough for full oscillator stabilization and register initialization. |
| Ultra-low 4 µA supply current | Enables continuous supervision in energy-sensitive applications such as battery-backed IoT nodes and wearables. |
| VCC = 1.0 V reset guarantee | Valid logic-level RST output maintained down to 1.0 V supply - prevents spurious release during deep brownout events. |
| SOT23-3 footprint compatibility | Pin-for-pin and functionally compatible with DS181x and MXD181x families - simplifies second-source qualification and design reuse. |
Applications
| Industrial PLC Controller | Portable Medical Monitor |
|---|---|
Use Scenario: Power supply fluctuation during field deployment causes intermittent MCU lockup in programmable logic controllers. IC Role / Device Role / Timing Role: Reset supervisor asserting active-low RST to hold MCU in reset until 3.3 V rail stabilizes post-brownout. Use Value: Prevents corrupted I/O state and firmware crashes by enforcing ≥100 ms reset hold time after VCC recovery - meeting IEC 61000-4-29 immunity requirements. |
Use Scenario: Battery-powered vital signs monitor must retain reliable boot sequence across varying Li-ion cell voltage (3.0–4.2 V). IC Role / Device Role / Timing Role: Monitors 3.3 V LDO output and triggers reset if voltage sags below 3.06 V due to load transients or aging cells. Use Value: Guarantees clean MCU restart before sensor data acquisition begins - critical for FDA Class II device functional safety compliance. |
| Automotive Body Control Module | Smart Energy Meter |
Use Scenario: Load dump and cold-crank transients on 3.3 V domain risk incomplete MCU initialization in body electronics. IC Role / Device Role / Timing Role: Active-low push-pull reset supervisor providing robust VCC monitoring with transient immunity up to 100 mV/20 µs. Use Value: Eliminates need for external RC timing network while maintaining AEC-Q100 Grade 2 temperature performance (–40 °C to +105 °C). |
Use Scenario: M-Bus communication interface experiences sporadic resets due to 3.3 V rail instability during RF transmission bursts. IC Role / Device Role / Timing Role: Low-quiescent-current supervisor ensuring deterministic reset assertion during 3.0 V/3.3 V supply dips caused by GSM/GPRS transmit peaks. Use Value: 4 µA supply current extends meter battery life beyond 10 years; SOT23-3 footprint enables placement near power management IC. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar reset supervisor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX809TRD3T | 3.08 V threshold (±2%), 140 ms reset timeout, 1.2 µA max quiescent current - lower power but longer timeout. | Lacks guaranteed operation down to VCC = 1.0 V; specified only to 1.2 V - unsuitable for deep brownout scenarios. | Select when ultra-low power dominates over brownout depth tolerance; verify MCU reset release timing with extended trec. |
| TPS3808G30DBVR | 3.0 V threshold (±0.5%), adjustable timeout via capacitor, 1.5 µA quiescent current - higher accuracy, programmable delay. | Requires external timing capacitor; not pin-compatible; larger SOT23-5 footprint - increases layout complexity and BOM count. | Choose when tighter threshold tolerance (±0.5%) or configurable reset duration is required; accept added component and routing overhead. |
Compared with MAX809TRD3T and TPS3808G30DBVR, STM1815SWX7F delivers optimal balance of guaranteed 1.0 V operation, fixed 100 ms timing, and SOT23-3 compatibility - making it ideal for cost-sensitive, space-constrained 3.3 V systems where deterministic brownout response is critical.
Availability
STM1815SWX7F is available at Aetrix Electronics and suitable for industrial automation, portable medical devices, automotive body electronics, and smart metering applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.
Supply support for STM1815SWX7F 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 specializing in microcontrollers, power management, and analog/mixed-signal ICs, with strong focus on industrial, automotive, and consumer markets.
STM181x is ST's low-power reset supervisor product line, engineered specifically for reliable power-on reset and brownout protection in 3 V/3.3 V/5 V microcontroller systems - emphasizing precision, low quiescent current, and robust transient immunity.
FAQ
What is the exact reset threshold voltage for STM1815SWX7F?
The STM1815SWX7F has a factory-trimmed nominal reset threshold of 3.06 V, with ±2.5% accuracy guaranteed over the full operating temperature range (–40 °C to +105 °C). This value is confirmed in Table 3 of the official STMicroelectronics datasheet (Doc ID11464 Rev 8) and applies to all units within the STM1815 family bearing the WX7F suffix.
Does STM1815SWX7F support manual reset via an external push-button?
No. STM1815SWX7F does not include manual reset detect functionality. That feature is exclusive to the STM1813 and STM1818 variants, which incorporate debounced push-button detection circuitry on the RST pin. STM1815 uses a dedicated active-low push-pull RST output without bidirectional or MR-detect capability.
Can STM1815SWX7F be used with a 5 V supply rail?
No. STM1815SWX7F is specifically configured for 3.3 V/3.0 V systems with a 3.06 V threshold. For 5 V applications, ST recommends STM1810 or STM1811 (with 4.37 V or 4.62 V thresholds). Using STM1815 on 5 V would result in permanent reset assertion, as VCC exceeds the threshold by >1.9 V.
Is STM1815SWX7F pin-compatible with DS1815?
Yes. STM1815SWX7F is fully pin-compatible and functionally equivalent to Maxim's DS1815 in the SOT23-3 package. Both share identical pinout (RST/VCC/VSS), active-low push-pull output behavior, 3.06 V threshold, and 100 ms reset timeout - enabling direct substitution without layout changes.
STM1815SWX7F Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Programmable:
- Not Verified
- Type:
- Simple Reset/Power-On Reset
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 2.88V
- Output:
- Push-Pull, Totem Pole
- Reset:
- Active Low
- Reset Timeout:
- 100ms Minimum
- Operating Temperature:
- -40°C ~ 105°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
STM1815SWX7F FAQ
1.How can I place an order for STM1815SWX7F through Aetrix?
Please submit a Request for Quotation (RFQ) for STM1815SWX7F 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 STM1815SWX7F reliable?
The price and inventory of STM1815SWX7F are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STM1815SWX7F is usually 5 days.
3.What payment methods are accepted for STM1815SWX7F?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STM1815SWX7F transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STM1815SWX7F?
STM1815SWX7F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STM1815SWX7F 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 STM1815SWX7F?
For technical support, including STM1815SWX7F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STM1815SWX7F requirements.
6.How does Aetrix verify that STM1815SWX7F is sourced from the original manufacturer or authorized distributors?
All STM1815SWX7F 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 STM1815SWX7F meets industry standards.
7.What is the process for return or replacement of STM1815SWX7F?
All STM1815SWX7F units undergo pre-shipment inspection (PSI). If there is an issue with STM1815SWX7F, 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 STM1815SWX7F part is unused and in its original packaging.
Return procedure for STM1815SWX7F:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
STM1815SWX7F 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
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MCP111T-300E/TT
Microchip Technology
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MCP120T-315I/TT
Microchip Technology
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MCP809T-315I/TT
Microchip Technology
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