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Texas Instruments BQ29312PWR
- Part No.:
- BQ29312PWR
- Manufacturer:
- Texas Instruments
- Category:
- Battery Management
- Package:
- 24-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
BQ29312PWR.pdf
- Description:
- IC BATT PROT LI-ION 2-4C 24TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,129
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Product details
Overview
BQ29312PWR from Texas Instruments is a 2-, 3-, or 4-cell lithium-ion/polymer battery protection analog front-end (AFE) IC with integrated 3.3-V/25-mA LDO, I²C-compatible interface, and programmable overcurrent/short-circuit protection. It monitors individual cell voltages (±1% error), drives charge/discharge FETs, enables cell balancing via external resistors, and supports sleep/ship power modes. Used in notebook PCs and portable medical instrumentation for pack-level safety and host-managed battery management.
For engineers reviewing the BQ29312PWR datasheet, BQ29312PWR pinout, BQ29312PWR application, or BQ29312PWR equivalent, key selection criteria include its 4.5–25-V supply range, 60-µA typical quiescent current in normal mode, programmable OL/SC thresholds (50–205 mV / 100–475 mV), 0.15× cell voltage scaling accuracy, and TSSOP-24 package compatibility with bq2084 gas gauge systems.
Technical Context
The BQ29312PWR implements dual-tier overcurrent protection with independent programmable thresholds and blanking delays for charge and discharge paths-OL detection uses 5-mV steps (50–205 mV), SC detection uses 25-mV steps (100–475 mV). Its cell voltage monitor provides scaled GND-referenced outputs (0–4.5 V) with ±1% measurement error and supports calibration of gain (K = 0.150 ±0.003) and offset (≤±1 mV).
Power management includes three distinct modes: Normal (full functionality), Sleep (LDO + I²C active, FETs disabled), and Ship (REG off, 0.1–1.0 µA current). The WDI input serves dual roles-as 32.768-kHz watchdog clock and timing reference for OL/SC delay counters-with fault response times of 250–2000 ms startup detect and 100 µs oscillator-stop detection.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | 4.5 V to 25 V - Supports full operation across 2–4 Li-ion series stacks including pack+ and BAT inputs. |
| Quiescent Current (Normal) | 60 µA typical - Enables long-term monitoring without significant pack drain during system standby. |
| Cell Voltage Accuracy | ±1% error - Ensures reliable cell balancing and overvoltage/undervoltage cutoff decisions per cell. |
| Overload Threshold Range | 50 mV to 205 mV in 5-mV steps - Allows fine-tuned discharge current limiting to protect FETs and cells. |
| Short-Circuit Threshold Range | 100 mV to 475 mV in 25-mV steps - Configurable for fast shutdown during charge/discharge faults. |
| LDO Output | 3.3 V ±2% at ≤25 mA - Powers external circuitry (e.g., microcontroller, thermistor bias) with built-in current limiting. |
| I²C Interface Speed | Up to 100 kHz - Compatible with standard SMBus v1.1 hosts for real-time register access and status polling. |
Pinout & Package
TSSOP-24 package (PW), 0.65-mm pitch, 7.8-mm × 4.4-mm body, exposed thermal pad (GND-connected), rated for –25°C to +85°C ambient operation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| BAT | Primary power input | Diode-protected connection to battery stack positive; powers internal circuitry when PACK is absent. |
| PACK | Alternative power input | Connects to pack positive terminal; used for start-up and CHG FET drive; enables PMS-based CHG default state. |
| VC1–VC5 | Cell voltage sensing | Five terminals for measuring 2–4 series cell voltages and enabling cell balancing via internal FETs (rDS(on) = 400 Ω typ). |
| SR1/SR2 | Current sense differential pair | Measures voltage drop across external sense resistor (10–30 mΩ) to detect overload/short-circuit conditions. |
| CHG/DSG/ZVCHG | FET gate drivers | Push-pull outputs driving external N-channel FETs; CHG/DSG clamped to 15 V, ZVCHG regulated to 3.5 V. |
| REG | LDO output | 3.3-V regulated supply for host MCU, thermistor bias (TOUT), and I²C pull-ups; requires 4.7-µF capacitor. |
| SLEEP | Power mode control | Pulled up internally to REG; driven low to exit Sleep mode; floating or high enters Sleep mode. |
| XALERT | Status interrupt | Open-drain output pulled up to REG; asserts low on OL/SC fault, watchdog timeout, or SLEEP pin transition. |
| SDATA/SCLK | I²C interface | Open-drain bidirectional data/clock with internal 10-kΩ pull-ups to REG; supports SMBus v1.1 read/write sequences. |
Key Features
| Feature | Design Value |
|---|---|
| Programmable Overload Protection | 50–205 mV threshold with 1–31 ms blanking delay - Prevents nuisance tripping during motor startup or pulse loads. |
| Dual-Direction Short-Circuit Detection | Independent 100–475 mV thresholds for charge/discharge paths - Enables asymmetric fault handling for charger vs. load side risks. |
| Cell Balancing Control | Per-cell bypass path enabled via I²C register (CB[3:0]); max 10 mA current set by external resistor + 400-Ω internal FET - Reduces voltage drift during CC/CV charging. |
| Multi-Level Power Management | Three defined states: Normal (full function), Sleep (60-µA → 20–40-µA), Ship (0.1–1.0 µA) - Extends shelf life and reduces parasitic drain in storage. |
| Thermistor Bias Drive | TOUT pin delivers regulated current (max 1 mA) with ≤100-Ω output impedance - Supports direct 10-kΩ NTC thermistor connection without external bias circuitry. |
| Watchdog Timer with Dual Fault Modes | Startup timeout (700 ms) and runtime oscillator-stop detection (100 µs) - Ensures host MCU responsiveness before enabling FETs or entering critical states. |
Applications
| Notebook PC Battery Packs | Medical Portable Diagnostic Devices |
|---|---|
Use Scenario: 3-cell Li-ion pack powering portable ultrasound or ECG units with strict safety certification requirements. IC Role / Device Role / Timing Role: Primary AFE for cell-level voltage monitoring, FET control, and thermal supervision; interfaces with host MCU via I²C for real-time SoC estimation. Use Value: Enables UL/IEC 62133 compliance through precise ±1% cell voltage measurement and dual-tier OC/SC protection with configurable delays. |
Use Scenario: Rechargeable battery module in handheld blood glucose meters requiring zero-volt charge capability and long shelf life. IC Role / Device Role / Timing Role: Protection controller managing pre-charge, 0-V charging, and ship-mode entry; TOUT drives thermistor for temperature-compensated charging. Use Value: Achieves <1 µA ship current and supports 0-V battery recovery without external circuitry-reducing BOM count and qualification effort. |
| Industrial Handheld Test Equipment | Portable Gas Detection Instruments |
Use Scenario: Ruggedized multimeter or oscilloscope with hot-swappable Li-ion packs operating in wide ambient temperatures (–25°C to +85°C). IC Role / Device Role / Timing Role: Safety supervisor providing cell balancing, overtemperature alert via TOUT, and robust I²C communication under EMI-prone conditions. Use Value: Maintains 60-µA typical supply current across full temperature range while delivering accurate cell voltage scaling (0.15× ±0.003) for SoH tracking. |
Use Scenario: Intrinsically safe gas detector using 2-cell Li-polymer pack with mandatory fault logging and fail-safe shutdown. IC Role / Device Role / Timing Role: Fault-monitoring AFE asserting XALERT on OL/SC events and latching status until host clears LTCLR bit; supports certified shutdown sequences. Use Value: Provides hardware-enforced, non-bypassable protection layers (including watchdog-initiated FET disable) required for ATEX/IECEx-certified designs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar battery protection AFE applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BQ29330PW | Same TSSOP-24 package; adds integrated 32.768-kHz oscillator (eliminates external crystal); identical protection thresholds and LDO specs. | Reduces bill-of-materials count where crystal footprint and layout complexity must be minimized. | Select BQ29330PW when system-level timing stability allows internal oscillator use and PCB space is constrained. |
| MP2617DGS-Z | Monolithic 2–4 cell protector with integrated charge FETs; no I²C interface; fixed 100-mV OC threshold; 1.2-V LDO only. | Targeted at cost-sensitive, low-feature applications where host MCU interaction is unnecessary and discrete FETs are undesirable. | Choose MP2617DGS-Z only for simple, self-contained protection without host telemetry or programmability requirements. |
Compared with BQ29312PWR, BQ29330PW offers identical protection functionality plus integrated timing, reducing external components, while MP2617DGS-Z trades programmability and communication for integration and lower cost-making BQ29312PWR optimal for host-controlled, safety-certified systems needing calibrated voltage monitoring and flexible fault response.
Availability
BQ29312PWR is available at Aetrix Electronics and suitable for notebook PC battery packs, portable medical diagnostic devices, industrial handheld test equipment, and intrinsically safe gas detection instruments requiring stable component supply and long-lifecycle support.
Supply support for BQ29312PWR 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
Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and power management technologies, with decades of experience in battery management solutions.
The BQ29312PWR belongs to TI's battery protection AFE product line, designed specifically for high-accuracy, host-managed safety in multi-cell lithium-ion/polymer packs used in portable computing and medical devices.
FAQ
What is the primary function of the BQ29312PWR in a battery management system?
The BQ29312PWR serves as an analog front-end protection IC that monitors individual cell voltages, detects overcurrent/short-circuit faults, controls external charge/discharge FETs, enables cell balancing, and provides a 3.3-V LDO supply-all coordinated via I²C with a host battery gauge like the bq2084. Its core role is hardware-enforced safety for 2–4 series Li-ion/polymer packs.
Does the BQ29312PWR support zero-volt charging, and how is it implemented?
Yes, the BQ29312PWR supports zero-volt charging through its ZVCHG FET driver and dedicated ZVCHG pin, which regulates clamp voltage to 3.5 V (typ) to safely initiate charging of deeply discharged cells. This feature is enabled without external components and is documented in the functional description section of the SLUS546E datasheet for BQ29312PWR.
How does the BQ29312PWR handle cell voltage measurement accuracy, and can it be calibrated?
The BQ29312PWR achieves ±1% cell voltage measurement error using a precision scaling amplifier (0.15× gain) with factory-trimmed reference (0.975 V). It supports in-system calibration of both gain (K) and input offset voltage (VOS) via I²C-accessible registers and a four-step procedure outlined in the datasheet-enabling post-assembly correction for board-level tolerances affecting BQ29312PWR performance.
What are the power modes supported by the BQ29312PWR, and how do they differ in current consumption?
The BQ29312PWR supports Normal (60 µA typ), Sleep (20–40 µA), and Ship (0.1–1.0 µA) modes. Normal enables full protection and monitoring; Sleep disables FETs and fault detection but retains I²C access and RAM state; Ship shuts down REG, I²C, and memory-used for long-term storage. All modes are controlled via SLEEP pin or I²C registers in the BQ29312PWR.
Can the BQ29312PWR directly drive thermistors, and what is the maximum supported resistance?
Yes, the BQ29312PWR drives thermistors via its TOUT pin, which provides a regulated current source with ≤100-Ω output impedance. It is optimized for 10-kΩ NTC thermistors at 25°C, supporting full-range temperature measurement when paired with a host ADC. The TOUT circuit is enabled via bit 5 of the FUNCTION CTL register and draws minimal current when inactive-preserving efficiency in the BQ29312PWR design.
BQ29312PWR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 24-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Battery Protection
- Battery Chemistry:
- Lithium Ion/Polymer
- Number of Cells:
- 2 ~ 4
- Fault Protection:
- Over Current, Over/Under Voltage, Short Circuit
- Interface:
- I2C
- Operating Temperature:
- -25°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-TSSOP
BQ29312PWR FAQ
1.How can I place an order for BQ29312PWR through Aetrix?
Please submit a Request for Quotation (RFQ) for BQ29312PWR 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 BQ29312PWR reliable?
The price and inventory of BQ29312PWR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BQ29312PWR is usually 5 days.
3.What payment methods are accepted for BQ29312PWR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BQ29312PWR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BQ29312PWR?
BQ29312PWR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BQ29312PWR 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 BQ29312PWR?
For technical support, including BQ29312PWR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BQ29312PWR requirements.
6.How does Aetrix verify that BQ29312PWR is sourced from the original manufacturer or authorized distributors?
All BQ29312PWR 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 BQ29312PWR meets industry standards.
7.What is the process for return or replacement of BQ29312PWR?
All BQ29312PWR units undergo pre-shipment inspection (PSI). If there is an issue with BQ29312PWR, 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 BQ29312PWR part is unused and in its original packaging.
Return procedure for BQ29312PWR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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