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STMicroelectronics STC3115IQT
- Part No.:
- STC3115IQT
- Manufacturer:
- STMicroelectronics
- Category:
- Battery Management
- Package:
- 10-UFDFN
- Datasheet:
-
STC3115IQT.pdf
- Description:
- IC BATT MON GAS GAUGE 10DFN
- Quantity:
- Payment:
- Shipping:
Inventory:1,871
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Product details
Overview
STC3115IQT from STMicroelectronics is a dedicated battery gas gauge IC for Li-ion/Li-polymer cells in handheld devices, integrating Coulomb counting, voltage-mode SOC estimation, and programmable low-battery alarm output. It delivers 0.25% battery voltage monitoring accuracy, operates in mixed or voltage-only mode, and supports dual micro-packages: 1.4 × 2.0 mm 10-bump CSP and 2.0 × 3.0 mm DFN10 - used in mobile phones and portable medical equipment.
For engineers reviewing the STC3115IQT datasheet, STC3115IQT pinout, STC3115IQT application, or STC3115IQT equivalent, key selection criteria include its OptimGauge™ algorithm, 45 µA power-saving mode current, 32.768 kHz internal timebase, ALM open-drain alarm output, and dual operating modes (mixed/voltage) with automatic SOC drift compensation.
Technical Context
The STC3115IQT implements a dual-path gas gauge architecture: a 14-bit sigma-delta ADC performs current sensing (500 ms conversion, 5.88 µV LSB), voltage measurement (250 ms, 2.20 mV LSB), and temperature sensing (250 ms, 1 °C resolution). Its internal 32.768 Hz oscillator enables precise timing for periodic conversions without external components.
Operating mode selection (VMODE bit) determines functional scope: mixed mode activates continuous Coulomb counting alongside voltage/temperature sampling every 4 s and 16 s respectively; voltage mode disables current sensing to achieve 45 µA average consumption while retaining OCV-based SOC estimation using a built-in high-precision reference curve.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Voltage Accuracy | ±0.25% at 25 °C - ensures reliable SOC estimation from battery OCV under stable lab conditions |
| Current Sensing LSB | 5.88 µV - defines minimum detectable voltage drop across sense resistor for Coulomb integration |
| Power-Saving Mode Current | 45 µA average over 4 s - enables multi-day runtime in always-on battery monitoring applications |
| Internal Oscillator | 32.768 kHz ±2% - provides autonomous timing for ADC conversions and alarm logic without external crystal |
| Alarm Output Type | Open-drain ALM pin - requires external pull-up; supports flexible voltage-level interfacing with host MCU GPIO |
| Temperature Range | -40 °C to +85 °C operating - validated for consumer handheld environments including battery thermal stress zones |
| Supply Voltage Range | 2.7 V to 4.5 V - matches typical Li-ion cell voltage range during discharge and charging termination |
Pinout & Package
STC3115IQT is available in two qualified packages: 1.4 × 2.0 mm 10-bump flip-chip CSP and 2.0 × 3.0 mm DFN10. Both packages share identical pin functionality and I/O mapping per the official STMicroelectronics datasheet (DocID023755 Rev 9).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| ALM | Open-drain alarm output | Asserts low on low-SOC or low-voltage condition; requires external pull-up for level translation |
| SDA / SCL | I²C bidirectional data/clock | Supports standard/fast-mode I²C (up to 400 kHz); open-drain with internal weak pull-down |
| CG | Analog current-sense input | Accepts ±40 mV differential voltage from external sense resistor; referenced to isolated GND |
| VIN | Analog battery voltage input | Measures full-cell voltage (0–4.5 V); uses dedicated supply track to avoid noise coupling |
| BATD/CD | Battery detection & charge inhibit | Input detects battery presence; output (active-high) can disable external charger when triggered |
| RSTIO | Reset sense/control I/O | Input detects system reset; output drives open-drain signal to notify host of internal reset event |
| GND | Analog/digital ground | Must be connected *only* to sense resistor ground to preserve current measurement integrity |
| VCC | Supply input | 2.7–4.5 V main power; decoupled with 1 µF capacitor per layout guidelines |
Key Features
| Feature | Design Value |
|---|---|
| OptimGauge™ algorithm | Combines real-time Coulomb counting with voltage-mode OCV tracking to eliminate long-term SOC drift |
| Programmable dual-threshold alarm | Independent SOC (%) and voltage (mV-step) thresholds stored in REG_SOC_ALM and REG_ALARM_VOLTAGE |
| Battery swap detection | Robust OCV initialization at power-up prevents false SOC reporting after hot battery replacement |
| Internal temperature sensor | Monitors die temperature every 16 s (±3 °C accuracy) to auto-compensate voltage and current measurements |
| Mixed/voltage mode switching | Software-controlled VMODE bit enables dynamic trade-off between accuracy (mixed) and ultra-low power (voltage) |
Applications
| Mobile Phone Battery Management | Digital Camera Power Monitoring |
|---|---|
|
Use Scenario: Real-time battery state tracking during video capture, flash use, and wireless transmission. IC Role / Device Role / Timing Role: Gas gauge IC performing mixed-mode SOC estimation with 4-s voltage and 16-s temperature updates. Use Value: Prevents unexpected shutdown by triggering ALM output at 1% SOC while maintaining <0.5% voltage error across discharge curve. |
Use Scenario: Accurate remaining-shot count and low-power sleep mode entry in DSLR/mirrorless cameras. IC Role / Device Role / Timing Role: Voltage-mode gas gauge operating at 45 µA to extend standby time between shots. Use Value: Enables >7-day standby with accurate OCV-based SOC estimation, eliminating need for periodic wake-ups. |
| Portable Medical Monitor | Multimedia Player Runtime Estimation |
|
Use Scenario: Continuous battery health monitoring in FDA-cleared glucose meters and pulse oximeters. IC Role / Device Role / Timing Role: Dual-path gas gauge with battery swap detection ensuring valid SOC after field battery replacement. Use Value: Guarantees clinical-grade accuracy (±0.25% voltage, ±3 °C temp) for regulatory compliance and patient safety alerts. |
Use Scenario: Predictive runtime display and adaptive backlight dimming based on dynamic load changes. IC Role / Device Role / Timing Role: Mixed-mode operation during playback (Coulomb counting active), switching to voltage mode during pause. Use Value: Delivers ±2% end-of-discharge prediction accuracy across varying audio/video codecs and screen brightness levels. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar battery gas gauge applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BQ27426YZFT | TI device uses impedance tracking instead of OCV modeling; requires battery characterization; no integrated temperature sensor | Lacks built-in thermal compensation - demands external NTC and calibration effort for medical-grade accuracy | Choose if battery-specific learning is acceptable and host MCU has processing headroom for impedance tables |
| MAX17048G+T | Maxim device offers ModelGauge m3 algorithm but lacks programmable dual-threshold alarm output; ALRT pin only signals SOC threshold | No independent low-voltage alarm path - cannot replace STC3115IQT's dual-trigger ALM function in safety-critical designs | Select when single-threshold warning suffices and system already uses Maxim's fuel gauge ecosystem |
Compared with BQ27426YZFT and MAX17048G+T, the STC3115IQT uniquely integrates robust OCV-based SOC estimation, dual-alarm triggering, and battery swap detection in a single 10-pin package - reducing BOM count and qualification effort for handheld OEMs.
Availability
STC3115IQT is available at Aetrix Electronics and suitable for mobile phones, portable medical equipment, digital cameras, and multimedia players requiring stable component supply and long-lifecycle support.
Supply support for STC3115IQT 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, specializing in analog, MEMS, and power solutions for automotive, industrial, and consumer markets.
The STC3115 belongs to ST's battery management IC product line, engineered specifically for high-accuracy, low-power gas gauging in space-constrained handheld devices with Li-ion/Li-polymer batteries.
FAQ
What is the function of the RSTIO pin on STC3115IQT?
The RSTIO pin serves dual roles: as an input, it detects external system reset events; as an open-drain output, it signals internal reset conditions (e.g., power-on reset or watchdog timeout) to the host processor. Its behavior is controlled via register bits, and it shares electrical characteristics with the ALM pin - requiring an external pull-up resistor for proper logic-level interpretation.
How does the STC3115IQT handle battery aging compensation?
The STC3115IQT continuously compares Coulomb counter (CC) and voltage-mode (VM) SOC estimates, updating REG_CC_ADJ and REG_VM_ADJ registers with signed 16-bit adjustment factors (LSB = 1/512%). These values accumulate over time in ACC_CC_ADJ and ACC_VM_ADJ, enabling automatic correction for capacity loss and internal resistance increase - no host firmware intervention is required for baseline aging compensation.
Can the STC3115IQT operate without an external current-sense resistor?
Yes - the STC3115IQT supports voltage-only mode (VMODE = 1), disabling current sensing entirely. In this configuration, it relies solely on its internal OptimGauge™ voltage algorithm and OCV lookup table for SOC estimation, consuming only 45 µA average current. This mode is ideal for applications where size, cost, or layout constraints preclude adding a precision sense resistor.
What is the significance of the BATD/CD pin in handheld designs?
The BATD/CD pin enables two critical functions: battery presence detection (input) and charge inhibit control (output). When configured as output, it asserts high to disable external chargers during abnormal conditions (e.g., overtemperature or invalid battery insertion), enhancing safety in consumer handhelds. Its hysteresis (0.1 V) prevents chatter during marginal battery contact scenarios.
STC3115IQT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- OptimGauge™
- Package/Case:
- 10-UFDFN
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Battery Monitor
- Battery Chemistry:
- -
- Number of Cells:
- -
- Fault Protection:
- -
- Interface:
- I2C
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 10-DFN (3x2)
STC3115IQT FAQ
1.How can I place an order for STC3115IQT through Aetrix?
Please submit a Request for Quotation (RFQ) for STC3115IQT 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 STC3115IQT reliable?
The price and inventory of STC3115IQT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STC3115IQT is usually 5 days.
3.What payment methods are accepted for STC3115IQT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STC3115IQT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STC3115IQT?
STC3115IQT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STC3115IQT 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 STC3115IQT?
For technical support, including STC3115IQT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STC3115IQT requirements.
6.How does Aetrix verify that STC3115IQT is sourced from the original manufacturer or authorized distributors?
All STC3115IQT 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 STC3115IQT meets industry standards.
7.What is the process for return or replacement of STC3115IQT?
All STC3115IQT units undergo pre-shipment inspection (PSI). If there is an issue with STC3115IQT, 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 STC3115IQT part is unused and in its original packaging.
Return procedure for STC3115IQT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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