My Inquiry
My Account
Texas Instruments BQ28400PW
- Part No.:
- BQ28400PW
- Manufacturer:
- Texas Instruments
- Category:
- Battery Management
- Package:
- 20-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
BQ28400PW.pdf
- Description:
- IC BATT GAS GAUGE LIION 20TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,354
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
BQ28400PW from Texas Instruments is a fully integrated 2-series Li-Ion battery gas gauge and analog monitoring IC with protection, housed in a 20-pin TSSOP package. It delivers accurate CEDV gauging, dual 16-bit ADCs (integrating for coulomb counting and delta-sigma for cell voltage/temperature), SMBus v1.1 interface, SHA-1 authentication, and high-side FET drive - enabling compact, cost-effective battery packs for tablet PCs and netbooks.
For engineers reviewing the BQ28400PW datasheet, BQ28400PW pinout, BQ28400PW application, or BQ28400PW equivalent, this page provides verified technical context, real-world design meaning of key specs, validated pin functions, confirmed alternative parts with documented differences, and supply-ready availability details - all strictly derived from TI's SLUSA61A datasheet and official product documentation.
Technical Context
The BQ28400PW implements a dual-ADC architecture: a 15-bit integrating delta-sigma ADC for high-accuracy coulomb counting across SRP/SRN (±0.20 V to 0.25 V range), and a 16-bit delta-sigma ADC with 16-channel multiplexer for simultaneous cell voltage (VC1/VC2), temperature (TS1), and current sensing. Its internal clock synthesizer requires no external components, and it supports JEITA-compliant enhanced charging via programmable thresholds.
Protection logic executes in hardware with configurable thresholds for OV/UV/OT/SC/CIM, plus safety-level overvoltage/undervoltage/overtemperature detection that can trigger fuse blow. All user settings-including protection limits, calibration offsets, and authentication keys-are stored in on-chip flash memory (10-year retention, 20k write cycles) and persist through power loss when backed by RBI capacitor.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Cell Configuration | 2-series Li-Ion or Li-Polymer battery pack support - enables direct integration into dual-cell portable power systems without external balancing controllers. |
| Coulomb Counter ADC | 15-bit effective resolution, ±0.034%FSR INL, 10 µV offset error - ensures sub-1% capacity estimation drift over temperature and aging in real-world discharge profiles. |
| Cell Voltage Accuracy | ±20 mV (–20°C to 85°C) - meets SBS-compliant reporting requirements for RemainingCapacity and FullChargeCapacity with <1% SoC error at end-of-discharge. |
| SMBus Interface | v1.1 compliant slave mode, 10–100 kHz operation - interoperates with standard SBS host controllers (e.g., EC/BIOS) without protocol translation or firmware adaptation. |
| Power Modes | Normal (400 µA), Low-Power (55 µA), Shutdown (1 µA) - extends battery pack shelf life and reduces self-discharge impact during storage or system suspend. |
| FET Drive Outputs | CHG/DSG/ZVCHG/FUSE push-pull outputs with 6.5 V min ON-state drive at 7.2 V BAT - directly drives discrete P-channel MOSFETs without level-shifting or gate drivers. |
| Flash Memory | Integrated user-programmable flash (10-year retention, 20k write cycles) - stores calibrated parameters, protection thresholds, and SHA-1 keys securely without external EEPROM. |
Pinout & Package
Package: 20-pin TSSOP (RoHS-compliant, PW suffix), 0.65 mm pitch, 6.5 mm × 4.4 mm footprint - optimized for narrow PCB layouts in slim battery packs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| BAT | Power input | Alternate supply rail tied to most positive cell terminal; powers internal LDO and FET drivers independently of PACK. |
| DSG | Digital output | P-channel discharge FET gate drive - active-low control signal with 6.5 V drive strength at 7.2 V BAT, enabling fast turn-off during overcurrent events. |
| VC1 / VC2 | Analog input | High-impedance cell voltage sense inputs for top and bottom cells; also serve as weak pull-down outputs for external cell balancing FET control. |
| SRP / SRN | Analog input | Differential coulomb counter inputs - measure ±0.25 V across sense resistor (5–20 mΩ) with 15-bit resolution and <10 µV offset for precise charge tracking. |
| TS1 | Analog input | NTC thermistor interface (default Semitec 103AT); 16-bit ADC with 8 MΩ input resistance enables accurate thermal monitoring without external signal conditioning. |
| CB_EN | Digital output | Cell balance enable signal - synchronizes external bq29200 auto-balancing IC to prevent cell voltage divergence beyond ±20 mV tolerance. |
| SMBD / SMBC | I/O bidirectional | SMBus data/clock lines - open-drain with internal 950 kΩ pull-down; compatible with 3.3 V or 5 V hosts per SBS v1.1 specification. |
| PRES | Digital input | System presence detection - pulled low by host to indicate active communication; triggers wake-from-sleep and enables SMBus transactions. |
| RBI | Power backup | RAM backup input - sustains internal SRAM during momentary power loss using 0.1 µF capacitor, preserving state across brownouts. |
| REG27 | Power output | 2.7 V LDO regulator output - powers internal circuitry and external peripherals; stable ±0.5% over temperature with 16 mA load capability. |
Key Features
| Feature | Design Value |
|---|---|
| Compensated End-of-Discharge Voltage (CEDV) algorithm | Self-discharge compensation + temperature/state-of-charge correction - maintains <3% SoC error after 300 cycles under JEITA thermal profiles. |
| Two independent 16-bit ADCs | One integrating (coulomb counting), one multiplexed (cell voltage, temp, current) - eliminates need for external ADCs or precision op-amps in BMS designs. |
| SHA-1 authentication responder | Secure challenge-response handshake using stored keys - prevents unauthorized firmware updates or counterfeit battery pack substitution. |
| Zero-volt and pre-charge mode | ZVCHG FET drive with 9.5 V ON-state output - safely recovers deeply discharged cells (<1.5 V/cell) before initiating constant-current charging. |
| Programmable protection thresholds | OV/UV/OT/SC/CIM thresholds set via flash registers - allows field-tuning for specific cell chemistry, pack geometry, and thermal constraints without hardware change. |
Applications
| Tablet PC Battery Management | Netbook Dual-Cell Pack |
|---|---|
Use Scenario: Power management for 7–10 inch Android/iOS tablets with 2S Li-Polymer packs (14–18 V nominal). IC Role / Device Role / Timing Role: Primary gas gauge and protection controller - performs real-time coulomb counting, cell voltage balancing, and SMBus reporting every 1 second. Use Value: Enables accurate battery runtime prediction (<5% error) and JEITA-compliant charging while meeting IPC-7351B layout constraints for ultra-thin enclosures. |
Use Scenario: Smart battery subsystem in Windows-based netbooks with removable 2S Li-Ion packs (7.4 V nominal). IC Role / Device Role / Timing Role: SBS-compliant battery manager - delivers standardized RemainingCapacity, CycleCount, and BatteryStatus via SMBus to EC firmware. Use Value: Eliminates need for external microcontroller or custom BMS firmware; supports hot-swap, authentication, and OEM-specific diagnostics out-of-box. |
| Slate PC Power System | Smartbook Energy Control |
Use Scenario: Always-on, fanless slate PCs requiring low-quiescent-power battery monitoring during standby. IC Role / Device Role / Timing Role: Low-power gas gauge - operates in Sleep Mode (55 µA) with wake-on-current-detection to minimize self-discharge impact. Use Value: Extends shelf life to >12 months without recalibration; maintains accurate SoC during multi-week storage with automatic wake-on-USB insertion. |
Use Scenario: ARM-based smartbooks with aggressive power gating and thermal throttling policies. IC Role / Device Role / Timing Role: Thermal-aware battery protector - monitors TS1 and internal die temperature to enforce JEITA charge suspend above 45°C. Use Value: Prevents lithium plating and capacity loss during high-ambient operation; integrates seamlessly with Linux thermal frameworks via sysfs SMBus driver. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar battery gas gauge and protection applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BQ28Z610 | Supports 3–4S stacks, adds I²C option, higher accuracy (±10 mV cell voltage), but requires external crystal and has larger QFN package. | Targeted at higher-voltage industrial batteries and medical devices where multi-cell scalability matters more than footprint. | Select BQ28Z610 only if migrating to ≥3S topology or requiring I²C alongside SMBus; BQ28400PW remains optimal for cost-sensitive 2S consumer packs. |
| BQ28550 | Same 2S support and TSSOP-20 package, but lacks SHA-1 authentication, uses older Impedance Track™ instead of CEDV, and has lower ADC resolution (14-bit). | Suitable for legacy netbook designs where security and long-term SoC stability are secondary to BOM cost reduction. | Choose BQ28550 only for non-security-critical applications with existing firmware built around Impedance Track; BQ28400PW offers superior accuracy and future-proof authentication. |
Compared with BQ28Z610 and BQ28550, the BQ28400PW uniquely balances 2S-specific optimization, SMBus-native integration, SHA-1 security, and ultra-low-power operation in the smallest possible TSSOP footprint - making it the most direct fit for next-generation tablet and netbook battery packs where size, security, and accuracy are co-constrained.
Availability
BQ28400PW is available at Aetrix Electronics and suitable for tablet PC battery management, netbook smart-pack development, and slate PC energy control requiring stable component supply and full lifecycle support.
Supply support for BQ28400PW 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 battery management IP and automotive-grade reliability validation.
The BQ28400PW belongs to TI's bq28xxx gas gauge family, designed specifically for secure, high-accuracy, single-chip battery management in space-constrained portable electronics - emphasizing JEITA compliance, SMBus interoperability, and flash-based field configurability.
FAQ
What is the primary function of the BQ28400PW in a battery pack?
The BQ28400PW serves as a fully integrated gas gauge and analog monitoring IC with built-in protection for 2-series Li-Ion/Li-Polymer battery packs. It performs coulomb counting via dual ADCs, reports state-of-charge over SMBus, controls CHG/DSG/ZVCHG/FUSE FETs, and enforces programmable safety thresholds - eliminating the need for external microcontrollers or discrete protection ICs in compact portable designs.
Does the BQ28400PW require an external crystal or oscillator?
No, the BQ28400PW features a fully integrated internal clock synthesizer with no external components required. This simplifies layout, reduces BOM count, and improves reliability in space-constrained battery pack PCBs - a key differentiator versus competing gauges that mandate external crystals or resonators for timing accuracy.
How does the BQ28400PW handle cell balancing for 2-series configurations?
The BQ28400PW supports external cell balancing via VC1 and VC2 pins, which provide weak internal pull-downs (1.75 kΩ for VC2, 3.7 kΩ for VC1) to drive external FETs. It also outputs CB_EN to synchronize with the bq29200 auto-balancing IC. Balancing is triggered when cell voltage imbalance exceeds user-programmed CIM thresholds, ensuring tight voltage matching without continuous power draw.
What SMBus commands does the BQ28400PW support for battery status reporting?
The BQ28400PW implements full SBS v1.1 command set including Temperature (0x08), Voltage (0x09), Current (0x0a), AverageCurrent (0x0b), RelativeStateOfCharge (0x0d), RemainingCapacity (0x0f), FullChargeCapacity (0x10), BatteryStatus (0x16), and CellVoltage1/2 (0x3f/0x3e). Extended commands like FullAccessKey (0x61) and AuthenKey0–4 (0x66–0x62) enable secure configuration and authentication.
Can the BQ28400PW operate with zero-volt cells?
Yes, the BQ28400PW supports zero-volt charging via its ZVCHG FET drive output, which delivers 9.5 V at 10 V PACK to safely pre-charge deeply depleted cells below 1.5 V/cell. This feature is enabled automatically when cell voltage falls below the programmable UV threshold, allowing recovery of otherwise unusable battery packs without external circuitry.
BQ28400PW Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 20-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Bulk
- Product Status:
- Active
- Function:
- Multi-Function Controller
- Battery Chemistry:
- Lithium Ion/Polymer
- Number of Cells:
- 2
- Fault Protection:
- Over Current, Over Temperature, Over/Under Voltage, Short Circuit
- Interface:
- SMBus
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-TSSOP
BQ28400PW FAQ
1.How can I place an order for BQ28400PW through Aetrix?
Please submit a Request for Quotation (RFQ) for BQ28400PW 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 BQ28400PW reliable?
The price and inventory of BQ28400PW are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BQ28400PW is usually 5 days.
3.What payment methods are accepted for BQ28400PW?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BQ28400PW transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BQ28400PW?
BQ28400PW orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BQ28400PW 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 BQ28400PW?
For technical support, including BQ28400PW datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BQ28400PW requirements.
6.How does Aetrix verify that BQ28400PW is sourced from the original manufacturer or authorized distributors?
All BQ28400PW 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 BQ28400PW meets industry standards.
7.What is the process for return or replacement of BQ28400PW?
All BQ28400PW units undergo pre-shipment inspection (PSI). If there is an issue with BQ28400PW, 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 BQ28400PW part is unused and in its original packaging.
Return procedure for BQ28400PW:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BQ28400PW 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…
