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Texas Instruments BQ27421YZFT-G1D
- Part No.:
- BQ27421YZFT-G1D
- Manufacturer:
- Texas Instruments
- Category:
- Battery Management
- Package:
- 9-UFBGA, DSBGA
- Datasheet:
-
BQ27421YZFT-G1D.pdf
- Description:
- IC FUEL GAUGE LI-ION 1CL 9DSBGA
- Quantity:
- Payment:
- Shipping:
Inventory:354
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Product details
Overview
BQ27421YZFT-G1D from Texas Instruments is a system-side single-cell Li-ion 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 (%) for embedded or removable battery packs in space-constrained portable devices.
For engineers reviewing the BQ27421YZFT-G1D datasheet, BQ27421YZFT-G1D pinout, BQ27421YZFT-G1D application, or BQ27421YZFT-G1D equivalent, this page provides verified technical context, I²C timing compliance, coulomb counter resolution, thermal performance, and validated alternative options for battery fuel gauging design-in.
Technical Context
The BQ27421YZFT-G1D implements Texas Instruments' patented Impedance Track™ algorithm to model battery impedance, open-circuit voltage, and load-dependent voltage sag-enabling high-accuracy SOC estimation across temperature (–40°C to 85°C), aging, and discharge rate variations. Its integrated 16-bit coulomb counter measures current via the 7-mΩ on-die sense resistor between BAT and SRX pins.
It operates in five power modes (NORMAL, SLEEP, HIBERNATE, SHUTDOWN, INITIALIZATION) with sub-1-μA shutdown current and supports 400-kHz I²C FAST mode communication using fixed 7-bit address 0x55 (0xAA write / 0xAB read). Internal temperature sensing and host-reported temperature input are both supported.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Battery Type | Single-cell Li-ion (LiCoO₂), supports CHEM_ID 0x3142 for 4.3–4.4 V max charge voltage |
| Integrated Sense Resistor | 7 mΩ typical, enables direct current measurement without external shunt; rated for 2000 mA RMS continuous use |
| Coulomb Counter Resolution | 16-bit effective resolution, 1-second conversion time, ±25 mV input range (BAT–SRX) |
| I²C Interface | 400-kHz FAST mode compliant; fixed slave address 0x55; supports incremental read/write, quick read, 1-byte write |
| LDO Output | 1.8 V regulated output (VDD), decoupled by 0.47-μF ceramic capacitor; not intended to power external circuitry |
| Operating Temperature | –40°C to +85°C ambient; internal temperature sensor accuracy ±5°C over full range |
| Supply Current | 93 μA (NORMAL), 21 μA (SLEEP), 9 μA (HIBERNATE), 0.6 μA (SHUTDOWN) |
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) | LDO input & coulomb counter reference | Connects to PACK+; powers internal LDO and serves as ADC reference; requires 1-μF decoupling to VSS |
| SCL (A3) | I²C clock line | Open-drain, requires external 10-kΩ pullup to VPU (1.62–3.6 V); supports 400-kHz timing |
| SDA (A2) | I²C data line | Open-drain, requires external 10-kΩ pullup; supports bidirectional command/data transfer per I²C spec |
| GPOUT (A1) | Configurable digital output | Open-drain; defaults to SOC_INT pulse; configurable as BAT_LOW warning; must use 10-kΩ pullup if unused |
| BIN (B1) | Battery insertion detection input | Digital input; detects pack presence via pulldown resistor; default [BIE]=1 enables automatic detection |
| SRX (C2) | Coulomb counter sense input | Analog input referenced to BAT; connects to VSYS rail; measures voltage drop across integrated 7-mΩ resistor |
| VDD (B3) | LDO regulated output | 1.8-V supply for internal logic; decouple with 0.47-μF ceramic cap to VSS; not for external loads |
| VSS (B2, C1) | Ground reference | B2 is primary ground pin; C1 is floating but usable as board ground bridge; recommended trace routing B2→C1→PCB GND |
Key Features
| Feature | Design Value |
|---|---|
| Impedance Track™ Algorithm | Delivers <±2% SOC error across life cycle by modeling cell impedance, OCV, and dynamic voltage response-not just voltage or current integration alone |
| Integrated 7-mΩ Sense Resistor | Eliminates external shunt, reduces BOM count and PCB area, and avoids placement-induced thermal drift errors common with discrete resistors |
| 16-bit Coulomb Counter | Enables precise long-term capacity tracking with 1-second integration period and ±25 mV input range-optimized for low-current standby and high-pulse load profiles |
| Configurable GPOUT | Reduces MCU GPIO usage: can signal SOC threshold crossing or battery low condition without polling; exit-from-SHUTDOWN trigger via toggle |
| Multi-mode Power Management | Automated transition among NORMAL/SLEEP/HIBERNATE/SHUTDOWN ensures <1 μA quiescent draw during idle-critical for always-on portable devices |
Applications
| Smartphones | Tablets |
|---|---|
Use Scenario: Real-time battery level display and low-battery warning during active screen use and background app synchronization. IC Role / Device Role / Timing Role: System-side fuel gauge providing smoothed SOC % and remaining capacity (mAh) via I²C every 1–5 seconds. Use Value: Enables accurate "hours remaining" estimates and prevents unexpected shutdowns by detecting aging-induced capacity loss before end-user impact. |
Use Scenario: Multi-tasking with cellular, Wi-Fi, and display subsystems drawing variable current while maintaining >8-hour runtime. IC Role / Device Role / Timing Role: Host-controlled coulomb counter and Impedance Track™ estimator delivering filtered RM and SOH values at 2-second intervals. Use Value: Compensates for self-discharge and temperature gradients across large-format cells, improving runtime prediction accuracy by ≥3× vs. voltage-only methods. |
| Digital Cameras | Handheld Terminals |
Use Scenario: Burst-mode photo capture with flash, causing high-current pulses (≥2 A) followed by extended idle periods. IC Role / Device Role / Timing Role: High-accuracy current integration via integrated 7-mΩ resistor and 16-bit ADC, synchronized with camera firmware events. Use Value: Maintains <±3% SOC error despite 250-ms 3.5-A peak pulses-eliminating need for recalibration after flash use. |
Use Scenario: Ruggedized industrial scanner operating in wide ambient temperatures (–20°C to 60°C) with intermittent barcode scanning. IC Role / Device Role / Timing Role: Temperature-compensated fuel gauge using internal sensor or host-reported values to correct SOC for thermal drift. Use Value: Reduces cold-weather false-low warnings by 90% compared to uncompensated gauges, extending field usability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar single-cell Li-ion fuel gauging applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BQ27421YZFT-G1B | Same die, different CHEM_ID (0x312) calibrated for 4.3–4.35 V max charge; identical pinout, timing, and firmware interface | Targeted at LiCoO₂ cells with lower voltage ceiling; not interchangeable without reprogramming chemistry profile | Select only if battery chemistry matches 4.3–4.35 V specification; firmware update required for migration from BQ27421YZFT-G1D |
| BQ27441YZFT-G1 | Enhanced variant with higher accuracy ADC (17-bit coulomb counter), extended temperature range (–40°C to 105°C), and improved SOH algorithm | Supports automotive-grade thermal environments and longer-life battery systems; requires updated host driver for extended commands | Choose when operating above 85°C or requiring <±1.5% SOC accuracy over 500 cycles; not drop-in compatible due to firmware differences |
Compared with BQ27421YZFT-G1D, the G1B variant offers identical hardware but chemistry-specific calibration, while the BQ27441YZFT-G1 adds accuracy and thermal robustness at the cost of firmware compatibility-making the BQ27421YZFT-G1D optimal for cost-sensitive consumer designs with standard LiCoO₂ cells.
Availability
BQ27421YZFT-G1D is available at Aetrix Electronics and suitable for smartphones, tablets, and handheld terminals requiring stable component supply, long-term lifecycle support, and consistent Impedance Track™ fuel gauging performance.
Supply support for BQ27421YZFT-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 company specializing in analog, embedded processing, and power management technologies, with leadership in battery management ICs since 2005.
The BQ27421YZFT-G1D belongs to TI's bq27xxx fuel gauge family, designed specifically for system-side battery monitoring in space-constrained portable electronics-emphasizing minimal configuration, integrated sensing, and high-accuracy lifetime SOC estimation.
FAQ
What is the exact I²C slave address of the BQ27421YZFT-G1D?
The BQ27421YZFT-G1D uses a fixed 7-bit I²C slave address of 0x55. In 8-bit format, this corresponds to 0xAA for write operations and 0xAB for read operations. This address is hard-coded and cannot be modified. The device supports standard I²C protocols including incremental read/write, quick read, and 1-byte write-verified per Section 7.12 of the SLUSB85E datasheet.
Does the BQ27421YZFT-G1D require an external sense resistor?
No, the BQ27421YZFT-G1D does not require an external sense resistor. It integrates a precision 7-mΩ sense resistor between the BAT and SRX pins, enabling direct current measurement with no additional components. This eliminates layout sensitivity, thermal drift, and BOM cost associated with discrete shunts-confirmed in Section 1 (Features) and Table 7.10 of the SLUSB85E datasheet.
How does the BQ27421YZFT-G1D handle battery temperature measurement?
The BQ27421YZFT-G1D includes an internal temperature sensor for autonomous operation, delivering ±5°C accuracy from –40°C to 85°C. Alternatively, it accepts host-reported temperature via the OpConfig() command, allowing integration with external thermistors or system-level thermal sensors. Both methods feed the Impedance Track™ algorithm to correct SOC for thermal effects-detailed in Section 8.3 and Table 7.8.
What power modes does the BQ27421YZFT-G1D support, and what are their current draws?
The BQ27421YZFT-G1D supports five power modes: NORMAL (93 μA), SLEEP (21 μA), HIBERNATE (9 μA), SHUTDOWN (0.6 μA), and INITIALIZATION. Mode transitions occur automatically based on activity or can be triggered via Control() subcommands like SET_HIBERNATE or SHUTDOWN. All modes retain nonvolatile data and resume operation without recalibration-per Section 8.4 and Table 7.5 of SLUSB85E.
Can the BQ27421YZFT-G1D be used with batteries other than LiCoO₂?
The BQ27421YZFT-G1D is factory-configured for LiCoO₂ chemistry (CHEM_ID 0x3142, 4.3–4.4 V max charge), but TI provides downloadable chem IDs for LiMn₂O₄, LiFePO₄, and NMC via the bqStudio tool. Reconfiguration requires UNSEALED access and verified profile validation-however, BQ27421YZFT-G1D hardware is not qualified for non-Li-ion chemistries per TI documentation. Use only with TI-validated profiles.
BQ27421YZFT-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
BQ27421YZFT-G1D FAQ
1.How can I place an order for BQ27421YZFT-G1D through Aetrix?
Please submit a Request for Quotation (RFQ) for BQ27421YZFT-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 BQ27421YZFT-G1D reliable?
The price and inventory of BQ27421YZFT-G1D are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BQ27421YZFT-G1D is usually 5 days.
3.What payment methods are accepted for BQ27421YZFT-G1D?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BQ27421YZFT-G1D transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BQ27421YZFT-G1D?
BQ27421YZFT-G1D orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BQ27421YZFT-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 BQ27421YZFT-G1D?
For technical support, including BQ27421YZFT-G1D datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BQ27421YZFT-G1D requirements.
6.How does Aetrix verify that BQ27421YZFT-G1D is sourced from the original manufacturer or authorized distributors?
All BQ27421YZFT-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 BQ27421YZFT-G1D meets industry standards.
7.What is the process for return or replacement of BQ27421YZFT-G1D?
All BQ27421YZFT-G1D units undergo pre-shipment inspection (PSI). If there is an issue with BQ27421YZFT-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 BQ27421YZFT-G1D part is unused and in its original packaging.
Return procedure for BQ27421YZFT-G1D:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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