My Inquiry
My Account
Texas Instruments BQ29312APW
- Part No.:
- BQ29312APW
- Manufacturer:
- Texas Instruments
- Category:
- Battery Management
- Package:
- 24-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
BQ29312APW.pdf
- Description:
- IC BATT PROT LI-ION 2-4C 24TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:297
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
BQ29312APW 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% accuracy), supports cell balancing via external resistors, and drives CHG/DSG/ZVCHG FETs for pack-level safety control in portable instrumentation and medical equipment.
For engineers reviewing the BQ29312APW datasheet, BQ29312APW pinout, BQ29312APW application, or BQ29312APW equivalent, this device delivers precise per-cell voltage translation (0.15× scaling), dual-tier overcurrent detection with 5-mV/25-mV programmable thresholds, 60-µA typical supply current in active mode, and configurable sleep/ship power states for ultra-low-power battery management systems.
Technical Context
The BQ29312APW implements a dedicated analog front-end architecture for series-connected Li-ion packs, integrating independent voltage sensing across up to four cells (VC1–VC5), bidirectional current monitoring via SR1/SR2, and autonomous FET gate drive logic for charge/discharge control. Its 32-kHz watchdog timer uses the WDI input to enforce host responsiveness, while the I²C interface enables real-time register access to STATUS, CONTROL, and FUNCTION CTL registers.
Cell voltage translation employs a precision inverting amplifier with fixed gain (K = 0.150 ±0.003 V/V) and offset calibration capability, delivering scaled outputs (0–4.5 V) referenced to GND. Overload and short-circuit protection operate independently for charge and discharge paths, with blanking delays (1–31 ms overload, 0–915 µs short-circuit) set via dedicated registers and enforced without host intervention.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Cell Count Support | 2-, 3-, or 4-cell Li-ion/Li-polymer stacks - enables flexible pack design without hardware change |
| Supply Voltage Range | 4.5 V to 25 V - accepts input from BAT or PACK terminals, supports wide-range battery configurations |
| LDO Output | 3.3 V ±2% at ≤25 mA - powers internal circuitry and external host logic; requires 4.7-µF output capacitor |
| Quiescent Current | 60 µA typical - minimizes standby drain during normal operation |
| Overload Threshold | Programmable 50–205 mV in 5-mV steps - sets discharge current fault limit with 10-mV hysteresis |
| Short-Circuit Threshold | Charge: 100–475 mV; Discharge: –100 to –475 mV - dual-direction fault detection with 50-mV hysteresis |
| I²C Interface | Standard-mode (≤100 kHz), open-drain SCLK/SDATA with internal 10-kΩ pullups - enables host read/write of all configuration and status registers |
| Power Modes | Normal, Sleep (20–40 µA), Ship (0.1–1.0 µA) - software- and pin-controlled low-power states for long-term storage |
Pinout & Package
TSSOP-24 (PW) package with 0.65-mm pitch; thermally enhanced layout optimized for battery pack PCB integration.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| BAT | Primary power input | Diode-protected connection to most-positive cell; supplies REG when PACK is absent |
| PACK | Alternative power input | Connects to pack positive terminal; used for startup and alternate REG sourcing |
| VC1–VC5 | Cell voltage sense chain | Five inputs spanning full stack (VC1 = top cell+, VC5 = bottom cell−); enable per-cell monitoring and balancing |
| SR1/SR2 | Current sense differential pair | Measures voltage drop across external sense resistor (10–30 mΩ) for overload/short-circuit detection |
| CHG/DSG/ZVCHG | FET gate drivers | Push-pull outputs controlling external N-channel FETs; CHG/DSG clamped to 15 V, ZVCHG regulated to 3.5 V |
| REG | LDO output | 3.3-V supply for internal logic and external host; requires 4.7-µF ceramic capacitor |
| CELL | Scaled cell voltage output | Inverted 0.15× representation of selected cell voltage (0–4.5 V range), calibrated for <1% error |
| SLEEP | Power mode control | Pulled up internally to REG; grounding or driving to GND enters Sleep mode; floating or high maintains Normal mode |
| XALERT | Status interrupt | Open-drain output asserted low on OL/SC fault, watchdog timeout, or SLEEP pin transition |
| WDI | Watchdog clock input | Accepts 32.768-kHz signal to time protection delays and detect host oscillator failure |
Key Features
| Feature | Design Value |
|---|---|
| Per-cell voltage monitoring | 0.15× scaled output with ±1% accuracy and on-chip calibration support for <1% total error |
| Programmable overcurrent protection | 50–205 mV threshold in 5-mV steps with 1–31 ms blanking delay - prevents false trips during load transients |
| Dual-direction short-circuit detection | Separate 100–475 mV (charge) and –100 to –475 mV (discharge) thresholds with 50-mV hysteresis - ensures robust fault isolation |
| Integrated 3.3-V LDO | 25-mA output with line/load regulation ≤100 mV - eliminates need for external regulator in host system |
| Configurable power modes | Ship mode draws ≤1.0 µA; Sleep mode retains register state while disabling FETs and protection - extends shelf life |
| I²C-compatible serial interface | Full register access (STATUS, CONTROL, FUNCTION CTL) at ≤100 kHz - enables dynamic reconfiguration without reset |
Applications
| Medical Portable Monitors | Notebook PC Battery Packs |
|---|---|
Use Scenario: Continuous ECG/SpO₂ monitoring in handheld clinical devices requiring >72-hour runtime and safe 0-V recharge capability. IC Role / Device Role / Timing Role: AFE supervises 3-cell Li-polymer pack, enforces 200-mV short-circuit threshold during charging, and triggers XALERT on thermal fault via TOUT-driven thermistor. Use Value: Prevents cell imbalance-induced capacity loss through programmable cell balancing; 60-µA quiescent current extends idle battery life. |
Use Scenario: High-reliability battery protection in enterprise-grade notebooks where firmware-controlled FET sequencing must coexist with hardware safety limits. IC Role / Device Role / Timing Role: Host MCU reads CELL outputs via I²C to compute state-of-charge; BQ29312APW autonomously disables DSG FET if SR1–SR2 exceeds 150 mV for >5 ms. Use Value: Dual-tier OC/SC protection ensures no single-point failure bypasses safety; PMS pin configures CHG FET default state for factory programming. |
| Test Equipment Power Supplies | Industrial Handheld Scanners |
Use Scenario: Benchtop multimeters and oscilloscope probes powered by removable 4-cell Li-ion packs needing accurate voltage telemetry and ship-mode preservation. IC Role / Device Role / Timing Role: Measures VC1–VC4 to report individual cell health; enters Ship mode (0.1 µA) when PACK is disconnected and STATE CTL b1=1. Use Value: 4.5–25 V supply range accommodates aging packs; CELL output scaling enables direct ADC sampling without external op-amps. |
Use Scenario: Ruggedized barcode scanners deployed in warehouses where mechanical shock may induce transient overcurrent events. IC Role / Device Role / Timing Role: Uses WDI-driven watchdog to verify host MCU liveness; asserts OD open-drain output to disable motor driver on XALERT assertion. Use Value: 100-µs watchdog timeout detects frozen firmware; OD output provides fail-safe hardware interlock independent of I²C communication. |
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 | Supports 5-cell stacks; adds integrated 5-V boost converter for host power; higher 100-µA quiescent current | Required for >4-cell packs or systems needing auxiliary 5-V rail; not pin-compatible due to added BOOST pin | Select when expanding beyond 4 cells or powering host MCU from battery |
| MP2617GQ-Z | Monolithic 2–4 cell protector with integrated charge FETs; no I²C interface; fixed 100-mV OC threshold | Targeted at cost-sensitive consumer devices; lacks programmability and cell voltage telemetry | Choose for simplified BOM where host telemetry and fine-grained protection tuning are unnecessary |
Compared with BQ29312APW, the BQ29330PW extends cell count and adds power conversion but increases supply current and changes pinout, while the MP2617GQ-Z reduces system complexity at the expense of configurability and diagnostic visibility - making BQ29312APW optimal for designs requiring host-controlled safety and precise cell-level data.
Availability
BQ29312APW is available at Aetrix Electronics and suitable for medical portable monitors, notebook PC battery packs, test equipment power supplies, and industrial handheld scanners requiring stable component supply and long-term lifecycle support.
Supply support for BQ29312APW 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 and embedded processing technologies, with decades of expertise in battery management solutions.
The BQ29312APW belongs to TI's battery protection AFE product line, designed specifically for high-accuracy, multi-cell Li-ion pack supervision with programmable safety thresholds and host-controllable power states.
FAQ
What is the primary function of the BQ29312APW in a battery management system?
The BQ29312APW serves as a protection analog front-end for 2–4 cell Li-ion/Li-polymer battery packs. It continuously monitors individual cell voltages, pack current via SR1/SR2, and temperature via TOUT-driven thermistors. It autonomously controls external CHG/DSG/ZVCHG FETs to enforce overvoltage, undervoltage, overload, and short-circuit protections while providing I²C-accessible telemetry to the host microcontroller. The BQ29312APW integrates a 3.3-V LDO and supports sleep/ship modes to minimize system power consumption.
How does the BQ29312APW achieve <1% cell voltage measurement accuracy?
The BQ29312APW achieves <1% cell voltage accuracy through a combination of factory-trimmed gain (K = 0.150 ±0.003 V/V), calibrated offset correction, and on-chip reference voltage (0.975 V ±1%). Users can perform two-point calibration using the CAL0/CAL1 bits to measure and compensate for amplifier offset and scaling errors. The CELL output is an inverted, scaled representation (VOUT = –K × VIN + 0.975 V) that enables direct ADC sampling with minimal external components. This calibration process is documented in the BQ29312APW datasheet Section 10.
Can the BQ29312APW support 0-V charging, and how is it implemented?
Yes, the BQ29312APW supports 0-V charging through its ZVCHG FET drive and dedicated ZVCHG clamp circuitry. When the pack voltage falls below the normal operating range, the ZVCHG pin regulates to 3.5 V (typical) to enable precharge current flow into deeply discharged cells. This function operates independently of the main CHG/DSG FETs and is controlled via the OUTPUT CTL register. The BQ29312APW datasheet confirms this capability in the "Precharge and 0-V Charging-Theory of Operation" section, ensuring safe recovery of fully depleted Li-ion cells without requiring external circuitry.
What are the key differences between Sleep mode and Ship mode in the BQ29312APW?
Sleep mode (20–40 µA) retains register contents and allows I²C writes but disables FET outputs, OC/SC protection, and watchdog functions; exit occurs when SLEEP pin transitions or host clears STATE CTL b0. Ship mode (0.1–1.0 µA) completely shuts down REG, disables I²C, and invalidates RAM - activated only when PACK voltage is removed and STATE CTL b1 = 1. Both modes preserve battery shelf life, but Ship mode is intended for long-term storage while Sleep mode supports rapid wake-up during system idle periods. These distinctions are defined in Table 2 of the BQ29312APW datasheet.
Is the BQ29312APW pin-compatible with other members of the bq293xx family?
The BQ29312APW is 100% specification-compatible with the BQ29312, as confirmed in the datasheet's "Features" section. However, it is not pin-compatible with variants like the BQ29330PW (5-cell, added BOOST pin) or BQ29311 (no I²C interface). The TSSOP-24 (PW) footprint is shared across BQ29312A-series devices, but register maps and feature sets differ - for example, the BQ29312APW supports I²C while the BQ29311 uses SMBus-only communication. Always verify pin assignments and functional register compatibility before substitution.
BQ29312APW Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 24-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tube
- 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:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-TSSOP
BQ29312APW FAQ
1.How can I place an order for BQ29312APW through Aetrix?
Please submit a Request for Quotation (RFQ) for BQ29312APW 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 BQ29312APW reliable?
The price and inventory of BQ29312APW are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BQ29312APW is usually 5 days.
3.What payment methods are accepted for BQ29312APW?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BQ29312APW transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BQ29312APW?
BQ29312APW orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BQ29312APW 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 BQ29312APW?
For technical support, including BQ29312APW datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BQ29312APW requirements.
6.How does Aetrix verify that BQ29312APW is sourced from the original manufacturer or authorized distributors?
All BQ29312APW 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 BQ29312APW meets industry standards.
7.What is the process for return or replacement of BQ29312APW?
All BQ29312APW units undergo pre-shipment inspection (PSI). If there is an issue with BQ29312APW, 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 BQ29312APW part is unused and in its original packaging.
Return procedure for BQ29312APW:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BQ29312APW Tags
-
BQ29700DSER
Texas Instruments
-
S-8241ABKMC-GBKT2G
ABLIC Inc.
-
S-8241ABPMC-GBPT2G
ABLIC Inc.
-
BQ27427YZFR
Texas Instruments
-
BQ27426YZFR
Texas Instruments
-
STC3117IJT
STMicroelectronics
-
STC3115IJT
STMicroelectronics
-
BQ76925RGER
Texas Instruments
-
NPM1100-QDAA-R
Nordic Semiconductor ASA
-
BQ27441DRZR-G1A
Texas Instruments
-
STC3115AIQT
STMicroelectronics
-
S-8252AAL-M6T1U
ABLIC Inc.
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…
