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Texas Instruments BQ27421YZFR-G1D
- Part No.:
- BQ27421YZFR-G1D
- Manufacturer:
- Texas Instruments
- Category:
- Battery Management
- Package:
- 9-UFBGA, DSBGA
- Datasheet:
-
BQ27421YZFR-G1D.pdf
- Description:
- IC BATT FUEL GAUGE LI-ION 9DSBGA
- Quantity:
- Payment:
- Shipping:
Inventory:11,187
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Product details
Overview
BQ27421YZFR-G1D from Texas Instruments is a single-cell Li-ion system-side fuel gauge IC with integrated 7-mΩ sense resistor, Impedance Track™ algorithm, and 1.8-V LDO regulator. It delivers real-time remaining capacity (mAh), state-of-charge (%), battery voltage (mV), and state-of-health estimation while operating directly from the battery pack. It is designed for embedded or removable battery configurations in space-constrained portable electronics.
For engineers reviewing the BQ27421YZFR-G1D datasheet, BQ27421YZFR-G1D pinout, BQ27421YZFR-G1D application, or BQ27421YZFR-G1D equivalent, key selection criteria include integrated sense resistor value, I²C timing compliance at 400 kHz, coulomb counter resolution (16-bit), temperature accuracy (±5°C typical), and low-power shutdown current (0.6 µA).
Technical Context
The BQ27421YZFR-G1D implements Texas Instruments' patented Impedance Track™ algorithm to model battery impedance, open-circuit voltage, and load behavior across temperature and aging-enabling high-accuracy SOC prediction without host MCU intervention. Its integrated 7-mΩ sense resistor enables direct current measurement between PACK+ and VSYS, eliminating external shunt components.
It operates in five power modes-NORMAL (93 µA), SLEEP (21 µA), HIBERNATE (9 µA), SHUTDOWN (0.6 µA), and INITIALIZATION-with automatic transitions triggered by battery insertion, voltage thresholds, or host commands. The device supports 400-kHz I²C communication using fixed 7-bit address 0x55 (0xAA write / 0xAB read) and includes configurable GPOUT for BAT_LOW or SOC_INT signaling.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Battery Type | Single-cell LiCoO₂ (CHEM_ID = 0x3142, max charge 4.3–4.4 V) |
| Integrated Sense Resistor | 7 mΩ (temperature-compensated firmware; supports ≤3.5 A peak pulsed current) |
| Coulomb Counter Resolution | 16-bit effective resolution; 1-second conversion time per sample |
| I²C Interface Speed | Up to 400 kHz FAST mode; fixed slave address 0x55 (0xAA/0xAB) |
| LDO Output | 1.8 V regulated output (VDD); decoupled with 0.47 µF ceramic capacitor |
| Operating Temperature | –40°C to +85°C ambient; internal temp sensor ±5°C accuracy |
| Supply Current (SHUTDOWN) | 0.6 µA - enables ultra-low-power battery monitoring during system sleep |
Pinout & Package
Package: DSBGA-9 (YZF), 1.62 mm × 1.58 mm, 0.5-mm pitch, NanoFree™ chip-scale package. Thermal resistance RθJA = 107.8°C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| BAT (C3) | Battery voltage input & coulomb counter reference | Connects to PACK+; powers LDO and ADC; requires 1-µF decoupling to VSS |
| SRX (C2) | Coulomb counter sense input | Measures voltage drop across integrated 7-mΩ resistor; connects to VSYS rail |
| VSS (B2, C1) | Ground reference | B2 is primary ground; C1 is floating but usable as board ground bridge - route B2→C1 on top layer |
| VDD (B3) | 1.8-V LDO output | Powers internal circuitry only; not for external loads; requires 0.47-µF decoupling |
| SCL (A3) / SDA (A2) | I²C bidirectional bus interface | Open-drain; require external 10-kΩ pullups to VPU (1.62–3.6 V); support 400-kHz timing |
| GPOUT (A1) | Configurable digital output | Default: SOC interrupt pulse; configurable as BAT_LOW warning; requires 10-kΩ pullup if unused |
| BIN (B1) | Battery insertion detection input | Logic-level input; default detects removal via 1.8-MΩ pullup; supports embedded/removable battery detection |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 7-mΩ sense resistor | Eliminates external shunt, reduces BOM count, and minimizes PCB area in battery-connected systems |
| Impedance Track™ algorithm | Delivers <±2% SOC error across discharge cycles, temperature, and aging without host calibration |
| 16-bit coulomb counter with 1-s integration | Enables precise charge/discharge tracking for runtime estimation in smartphones and tablets |
| Configurable GPOUT with wake capability | Signals SOC threshold or low-battery event; toggling exits SHUTDOWN mode - no external wake line needed |
| Ultra-low SHUTDOWN current (0.6 µA) | Extends shelf life and standby time for devices requiring persistent battery monitoring |
Applications
| Smartphones | Tablets |
|---|---|
Use Scenario: Real-time battery level reporting and low-power alerting during active UI and deep sleep states. IC Role / Device Role / Timing Role: System-side fuel gauge providing mAh, %SOC, and SOH via I²C; triggers GPOUT on BAT_LOW. Use Value: Enables accurate battery life estimation and graceful OS shutdown before critical depletion - leveraging integrated sense resistor and 0.6-µA shutdown current. | Use Scenario: Runtime prediction across variable screen brightness, CPU load, and Wi-Fi usage profiles. IC Role / Device Role / Timing Role: Primary coulomb counter and OCV estimator; communicates SOC and average current every 5 seconds over I²C. Use Value: Delivers <±2% SOC accuracy over 300+ cycles using Impedance Track™ modeling - reducing need for periodic full recalibration. |
| Digital Cameras | Handheld Terminals |
Use Scenario: Fast battery status update during burst photo capture and video recording with thermal throttling. IC Role / Device Role / Timing Role: Measures instantaneous current (±3.5 A peak) and cell temperature to adjust SOC in real time. Use Value: Maintains SOC fidelity under high-pulse loads using 16-bit integrating ADC and firmware temperature compensation. | Use Scenario: Reliable battery state reporting in industrial barcode scanners with frequent cold/warm starts. IC Role / Device Role / Timing Role: Detects battery insertion/removal via BIN pin; reports SOH to indicate end-of-life before field failure. Use Value: Reduces service calls by predicting battery degradation - supported by aging-aware Impedance Track™ and 1.8-V LDO operation down to 2.45 V BAT. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar fuel gauging applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BQ27421YZFT-G1D | Same die, 0.4-mm pitch DSBGA-9 (YZF vs YZT); identical electrical specs and firmware | Requires tighter assembly tolerance due to smaller pad pitch; same footprint area | Select when board assembly process supports 0.4-mm pitch and higher placement accuracy |
| BQ27441-G1 | Higher-accuracy variant: 15-bit ADC for voltage, 16-bit for current; extended temp range (–40°C to +95°C) | Targeted at automotive infotainment and ruggedized handhelds requiring extended thermal margin | Choose for applications needing >85°C operation or tighter voltage accuracy (±0.1% vs ±0.12%) |
Compared with BQ27421YZFR-G1D, the YZFT-G1D offers identical functionality in a finer-pitch package for advanced assembly lines, while the BQ27441-G1 adds thermal robustness and enhanced ADC precision - making it suitable for mission-critical or high-temperature deployments where long-term SOC stability is paramount.
Availability
BQ27421YZFR-G1D is available at Aetrix Electronics and suitable for smartphones, tablets, and handheld terminals requiring stable component supply, consistent firmware revision control, and long-lifecycle availability for consumer electronics production.
Supply support for BQ27421YZFR-G1D 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 expertise in battery management ICs.
The bq274xx family was engineered specifically for compact, cost-sensitive portable devices requiring high-accuracy fuel gauging without external sense resistors or complex host calibration - targeting smartphones, wearables, and IoT endpoints.
FAQ
What battery chemistries does the BQ27421YZFR-G1D support?
The BQ27421YZFR-G1D is factory-configured for LiCoO₂ chemistry with CHEM_ID = 0x3142, supporting 4.3–4.4 V maximum charge voltage. It uses Impedance Track™ modeling optimized for this profile; other chemistries require reconfiguration via DataFlash and are not guaranteed without validation. The BQ27421YZFR-G1D does not natively support LiFePO₄ or NMC without firmware customization.
How does the integrated 7-mΩ sense resistor affect current measurement accuracy in the BQ27421YZFR-G1D?
The BQ27421YZFR-G1D's integrated 7-mΩ resistor enables current sensing with ±0.5% gain error and firmware-based temperature compensation, achieving <±1% current accuracy across –40°C to 85°C. Its low value minimizes power loss (<17 mW at 1.5 A), and the 16-bit integrating ADC provides 1 mA resolution at 1-second intervals - critical for precise coulomb counting in the BQ27421YZFR-G1D.
Can the BQ27421YZFR-G1D operate without an external microcontroller?
No - the BQ27421YZFR-G1D is a peripheral IC requiring an external host MCU to initiate I²C commands (e.g., StateOfCharge(), RemainingCapacity()), configure OpConfig bits, and interpret data. It performs autonomous fuel gauging calculations but does not generate autonomous alerts or control battery FETs. All communication, configuration, and data retrieval for the BQ27421YZFR-G1D must be managed by the system host.
What is the purpose of the BIN pin on the BQ27421YZFR-G1D, and how should it be connected?
The BIN pin on the BQ27421YZFR-G1D detects battery presence: with default BIE=1, a logic low indicates insertion (via 10-kΩ pack pulldown), and high indicates removal (via 1.8-MΩ system pullup). For embedded batteries, connect BIN to VSS through 10-kΩ; leave BIE=1. Never short BIN to VDD/VSS directly. This pin enables the BQ27421YZFR-G1D to auto-initialize on pack insertion and maintain accurate SOC history across hot swaps.
Does the BQ27421YZFR-G1D include protection features like overvoltage or overcurrent shutdown?
No - the BQ27421YZFR-G1D is a dedicated fuel gauge IC and does not provide cell protection. It lacks hardware overvoltage, overcurrent, or overtemperature shutdown circuits. Protection functions (e.g., cut-off FET control) must be implemented externally using a separate protection IC or analog front-end. The BQ27421YZFR-G1D reports parameters like voltage, current, and temperature to enable host-based protection decisions - but it does not actuate them.
BQ27421YZFR-G1D Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- Impedance Track™
- Package/Case:
- 9-UFBGA, DSBGA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Battery Monitor
- Battery Chemistry:
- Lithium Ion
- Number of Cells:
- 1
- Fault Protection:
- -
- Interface:
- I2C
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 9-DSBGA
BQ27421YZFR-G1D FAQ
1.How can I place an order for BQ27421YZFR-G1D through Aetrix?
Please submit a Request for Quotation (RFQ) for BQ27421YZFR-G1D 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 BQ27421YZFR-G1D reliable?
The price and inventory of BQ27421YZFR-G1D are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BQ27421YZFR-G1D is usually 5 days.
3.What payment methods are accepted for BQ27421YZFR-G1D?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BQ27421YZFR-G1D transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BQ27421YZFR-G1D?
BQ27421YZFR-G1D orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BQ27421YZFR-G1D 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 BQ27421YZFR-G1D?
For technical support, including BQ27421YZFR-G1D datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BQ27421YZFR-G1D requirements.
6.How does Aetrix verify that BQ27421YZFR-G1D is sourced from the original manufacturer or authorized distributors?
All BQ27421YZFR-G1D 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 BQ27421YZFR-G1D meets industry standards.
7.What is the process for return or replacement of BQ27421YZFR-G1D?
All BQ27421YZFR-G1D units undergo pre-shipment inspection (PSI). If there is an issue with BQ27421YZFR-G1D, 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 BQ27421YZFR-G1D part is unused and in its original packaging.
Return procedure for BQ27421YZFR-G1D:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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