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Texas Instruments BQ29411PWR
- Part No.:
- BQ29411PWR
- Manufacturer:
- Texas Instruments
- Category:
- Battery Management
- Package:
- 8-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
BQ29411PWR.pdf
- Description:
- IC BATT PROT LI-ION 2-4CL 8TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,860
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Product details
Overview
BQ29411PWR from Texas Instruments is a secondary overvoltage protection IC for 2-, 3-, or 4-cell Li-ion battery packs, providing fixed 4.40 V per-cell overvoltage threshold with ±50 mV accuracy (TA = –20°C to 85°C), programmable delay via external capacitor on CD pin, and ultra-low 2 µA supply current. It operates across –40°C to 110°C and drives an external N-channel FET to blow a fuse during overvoltage events in notebook battery packs.
For engineers reviewing the BQ29411PWR datasheet, BQ29411PWR pinout, BQ29411PWR application, or BQ29411PWR equivalent, key selection criteria include cell-count flexibility (2–4 series), precision voltage threshold tolerance, delay time programmability, high ripple rejection, and compatibility with pulse-charge battery systems.
Technical Context
The BQ29411PWR implements independent per-cell voltage monitoring using precision internal references, triggering protection when any single cell exceeds 4.40 V. Its delay timing is generated by charging an external capacitor at 0.18 µA via the CD pin until 1.2 V is reached - enabling configurable response windows from 1 to 2 seconds with 0.22 µF.
It features differential input structure for VC1–VC2, VC2–VC3, VC3–VC4, and VC4–GND, supporting stable operation under high-ripple conditions and pulse charging. The OUT pin delivers rail-to-rail drive capability (1.5–2.5 V at 40 µA sink) and transitions high only after full delay expiration, resetting only when all cells fall below 4.40 V minus 320 mV hysteresis.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Overvoltage Threshold | 4.40 V per cell, fixed and factory-trimmed - ensures precise second-level cutoff before primary protector fails. |
| Threshold Accuracy | ±50 mV over –20°C to 85°C - guarantees reliable trip margin across industrial temperature range. |
| Supply Current | <2 µA typical - enables multi-year battery pack shelf life without significant self-discharge impact. |
| Delay Time Range | 1–2 s with 0.22 µF on CD pin - allows tuning to match charger overvoltage response time and avoid nuisance trips. |
| Operating Temperature | –40°C to 110°C - supports deployment in high-ambient environments like laptop battery compartments. |
| Input Voltage Range | 0–5 V differential per sense pair - accommodates full Li-ion cell voltage swing while rejecting common-mode noise. |
| Hysteresis | 320 mV - prevents oscillation during recovery and ensures clean reset after overvoltage clears. |
Pinout & Package
TSSOP-8 (PW) package: 3.0 mm × 4.4 mm, 1.2 mm max height, lead pitch 0.65 mm, RoHS-compliant NiPdAu finish, MSL Level-2-260°C-1 year.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (VC1) | Most positive cell voltage sense | Connects to top of battery stack; monitors highest-potential cell in series chain. |
| 2 (VC2) | Second most positive cell voltage sense | Monitors voltage between first and second cells; enables differential measurement across adjacent cells. |
| 3 (VC3) | Third most positive cell voltage sense | Supports 3- and 4-cell configurations; used with VC1/VC2/VC4 to isolate individual cell overvoltage. |
| 4 (GND) | Analog ground reference | Common return for all sense inputs and internal circuitry; must be low-impedance connection to battery negative. |
| 5 (VC4) | Least positive cell voltage sense | Connects to bottom cell's positive terminal; completes 4-cell monitoring path (VC4–GND = lowest cell). |
| 6 (CD) | Capacitor delay timer input | Charged at 0.18 µA to 1.2 V to set overvoltage response delay; decoupled externally for timing stability. |
| 7 (VDD) | Power supply input | Accepts 4–25 V; powers internal circuitry and provides bias for sense comparators and output driver. |
| 8 (OUT) | Protection output signal | Open-drain high-side driver; pulls high to activate external N-FET for fuse blowing during overvoltage event. |
Key Features
| Feature | Design Value |
|---|---|
| 2–4 cell configuration support | Single device adapts to varying pack topologies via pin-strapping (e.g., short VC1–VC2 for 3-cell mode), reducing BOM count. |
| Programmable overvoltage delay | External RC network on CD pin sets exact trip timing - avoids false triggers during transient overvoltage spikes. |
| High ripple rejection | Stable operation under ≥100 mVpp supply ripple - maintains accuracy during fast-charging cycles with switching noise. |
| Low-power shutdown mode | ICC < 2 µA at VDD = 4.3 V - preserves battery capacity during long-term storage without compromising protection readiness. |
| Differential cell sensing | Independent VCn–VC(n−1) inputs eliminate need for isolated sense lines - simplifies PCB layout and reduces component count. |
Applications
| Notebook Computer Battery Packs | Portable Instrumentation Power Systems |
|---|---|
Use Scenario: Multi-cell Li-ion packs in ultrabooks requiring redundant overvoltage protection beyond primary fuel gauge IC. IC Role / Device Role / Timing Role: Second-level hardware cutoff that activates only if primary protection fails or is bypassed during fast charging. Use Value: Prevents thermal runaway by forcing fuse blow at precisely 4.40 V per cell, independent of firmware or communication bus integrity. |
Use Scenario: Handheld test equipment with removable 3-series Li-ion battery modules subject to field-replaceable cell swaps. IC Role / Device Role / Timing Role: Standalone analog monitor verifying cell balance before enabling charge/discharge paths. Use Value: Eliminates reliance on microcontroller-based voltage checks - ensures protection remains active even during MCU reset or brownout. |
| Medical Portable Diagnostic Devices | Industrial Handheld Scanners |
Use Scenario: Battery-powered ultrasound probes operating in clinical environments where safety certification mandates dual-protection layers. IC Role / Device Role / Timing Role: Hardware-enforced voltage clamp acting as fail-safe barrier upstream of system power management IC. Use Value: Meets IEC 62133 Clause 8.3.2 requirement for secondary overvoltage protection with documented trip threshold and hysteresis. |
Use Scenario: Ruggedized barcode scanners deployed in warehouses with wide ambient temperature swings (–20°C to 60°C). IC Role / Device Role / Timing Role: Ambient-temperature-stable voltage supervisor ensuring consistent trip point across operational lifetime. Use Value: Maintains ±50 mV accuracy from –20°C to 85°C - avoids premature shutdown or delayed response in variable thermal conditions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar secondary overvoltage protection applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BQ29412PWR | Fixed 4.45 V overvoltage threshold; same pinout, timing, and accuracy specs. | Suitable for higher-voltage Li-ion chemistries (e.g., LiCoO₂ with extended upper limit). | Select when battery chemistry requires tighter margin above nominal 4.2 V and system tolerates higher trip point. |
| BQ29413PWR | Fixed 4.50 V threshold; identical package, temperature range, and delay architecture. | Used in specialized high-energy-density packs where 4.40 V is insufficient to prevent degradation. | Choose only if validated cell-level testing confirms safe operation up to 4.50 V and no derating is applied. |
Compared with BQ29411PWR, BQ29412PWR raises the trip threshold by 50 mV for enhanced energy utilization, while BQ29413PWR adds another 50 mV - both retain identical timing control, low-power behavior, and thermal performance but shift protection boundaries upward for specific cell formulations.
Availability
BQ29411PWR is available at Aetrix Electronics and suitable for notebook computer battery packs, portable instrumentation power systems, medical diagnostic devices, industrial handheld scanners, and ruggedized field equipment requiring stable component supply with long lifecycle support.
Supply support for BQ29411PWR 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 over 50 years of innovation in battery safety and precision analog ICs.
The bq2941x family was designed specifically for secondary overvoltage protection in multi-cell Li-ion battery packs, delivering hardware-based redundancy to complement primary fuel gauges and protect against catastrophic failure modes.
FAQ
What is the exact overvoltage protection threshold of the BQ29411PWR?
The BQ29411PWR has a fixed, factory-trimmed overvoltage detection threshold of 4.40 V per cell, with ±50 mV accuracy over –20°C to 85°C and ±80 mV over the full –40°C to 110°C operating range. This value is not adjustable and applies uniformly across all supported 2-, 3-, and 4-cell configurations. The BQ29411PWR uses internal precision references to maintain this threshold without external calibration components.
How does the BQ29411PWR implement programmable delay timing?
The BQ29411PWR implements programmable delay via its CD pin, which sources a constant 0.18 µA current to charge an external capacitor. When the capacitor voltage reaches 1.2 V, the OUT pin transitions high. For example, using a 0.22 µF capacitor yields a nominal delay of 1.5 seconds. The BQ29411PWR automatically discharges the capacitor if overvoltage clears before timeout, preserving full delay for subsequent events.
Can the BQ29411PWR be used in a 2-cell Li-ion battery configuration?
Yes, the BQ29411PWR supports 2-cell configurations by connecting VC1, VC2, and VC3 together to the positive terminal of the top cell, and VC4 to the positive terminal of the bottom cell, with GND tied to battery negative. This configuration uses only two sense points (VC1/VC2/VC3 node and VC4) and maintains full overvoltage detection accuracy. The BQ29411PWR's internal architecture validates this wiring per TI Application Note SLUS669G Figure 5.
What is the maximum supply voltage the BQ29411PWR can tolerate on VDD?
The BQ29411PWR supports a VDD supply voltage range of –0.3 V to 28 V, with recommended operation from 4 V to 25 V. This wide input range allows direct connection to the full battery stack voltage in 4-cell configurations (up to ~16.8 V fully charged) while maintaining functionality during partial discharge or input transients. Absolute maximum rating ensures robustness against load-dump or hot-swap events in the BQ29411PWR's target applications.
Is the BQ29411PWR still recommended for new designs?
No - the BQ29411PWR is marked "Not Recommended for New Designs" (NRND) per TI's official packaging addendum dated August 2008 and reaffirmed in the 2017 orderable device status table. While actively manufactured for legacy program support, TI advises new designs to evaluate modern alternatives such as the BQ77PL900 family for enhanced integration, diagnostics, and longevity. The BQ29411PWR remains viable for repair, replacement, and continuity builds where qualification timelines prohibit redesign.
BQ29411PWR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Function:
- Battery Protection
- Battery Chemistry:
- Lithium Ion
- Number of Cells:
- 2 ~ 4
- Fault Protection:
- Over Voltage
- Interface:
- -
- Operating Temperature:
- -40°C ~ 110°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-TSSOP
BQ29411PWR FAQ
1.How can I place an order for BQ29411PWR through Aetrix?
Please submit a Request for Quotation (RFQ) for BQ29411PWR 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 BQ29411PWR reliable?
The price and inventory of BQ29411PWR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BQ29411PWR is usually 5 days.
3.What payment methods are accepted for BQ29411PWR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BQ29411PWR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BQ29411PWR?
BQ29411PWR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BQ29411PWR 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 BQ29411PWR?
For technical support, including BQ29411PWR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BQ29411PWR requirements.
6.How does Aetrix verify that BQ29411PWR is sourced from the original manufacturer or authorized distributors?
All BQ29411PWR 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 BQ29411PWR meets industry standards.
7.What is the process for return or replacement of BQ29411PWR?
All BQ29411PWR units undergo pre-shipment inspection (PSI). If there is an issue with BQ29411PWR, 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 BQ29411PWR part is unused and in its original packaging.
Return procedure for BQ29411PWR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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