Key Selection Information
| Selection Parameter | Confirmed Information |
|---|---|
| Battery Configuration | 1S to 4S Li-Ion / Li-Polymer pack |
| Gauging Method | CEDV |
| Protection | Programmable voltage, current, temperature and permanent-failure protections |
| FET Architecture | High-side N-channel CHG/DSG protection FET drive |
| Cell Balancing | Internal bypass balancing; external balancing option for higher current |
| Host Interface | SMBus v1.1, 100 kHz with alternate 400 kHz mode |
| Security / Diagnostics | SHA-1 authentication, lifetime data logging and black-box records |
| Exact Package / Packing | VQFN (RSM), 32 pins, 4 mm × 4 mm; 3000-piece large tape and reel |
Product Overview
BQ4050RSMR is a 1S-to-4S smart-battery pack manager that combines CEDV fuel gauging, high-side protection-FET control, cell balancing, authentication, and long-term diagnostic logging. It is intended for packs where the battery electronics must own protection and report detailed operating history rather than only expose state of charge.
The CEDV gauge architecture differs from TI’s Impedance Track family even though both can report capacity and SOC. BQ4050 uses its own CEDV model while adding a broad protection framework that includes cell voltage, current, temperature, watchdog, timeout and permanent-failure conditions. Selecting it should therefore be based on both the desired gauging method and the pack safety architecture.
Integrated cell balancing can bypass up to about 10 mA per cell using the internal path. An external balancing circuit can be used when greater balancing current is required. The pack capacity, typical imbalance and acceptable correction time determine whether the internal path is sufficient.
For related devices, see HKEQGOO’s Battery Management category.
Technical Specifications
| Parameter | Verified Information |
|---|---|
| Manufacturer | Texas Instruments |
| Exact MPN | BQ4050RSMR |
| Cell Count | 1 to 4 series cells |
| Fuel-Gauge Algorithm | CEDV |
| Current Measurement | Integrating delta-sigma ADC across SRP/SRN |
| Current Measurement Range | ±0.1 V differential stated in feature description |
| Cell Balancing | Internal bypass; external balancing supported |
| Internal Balancing Current | Up to 10 mA stated in feature description |
| Host Interface | SMBus v1.1; 100 kHz nominal with alternate 400 kHz mode |
| Authentication | SHA-1 responder |
| Protection Outputs | High-side CHG/DSG FET drive plus FUSE output for secondary faults |
| Diagnostics | Lifetime data monitor and black-box event history |
| Package | VQFN (RSM), 32 pins, 4 mm × 4 mm |
| Manufacturer Status | Active / Production |
| Part Marking | BQ4050 |
Functional Highlights
High-side FET protection supports smart-pack fault handling
BQ4050 drives high-side N-channel protection FETs rather than relying on a simple low-side disconnect. FET ratings, gate network, precharge path and fault-recovery policy should be treated as part of the pack design because charge/discharge blocking and communication behavior interact during faults.
Internal cell balancing is convenient but intentionally low current
The internal bypass path can balance multiple cells simultaneously at currents up to approximately 10 mA. This may be appropriate for modest mismatch correction but can be slow in high-capacity packs or packs with larger imbalance. TI also supports external balancing where a higher balancing current is required.
Lifetime logging adds diagnostic value beyond SOC reporting
The device records extremes and events such as cell voltage, charge/discharge current, temperature, safety-event counts and balancing time. That information can support service or warranty analysis, but it also makes data-flash configuration and production programming part of the finished battery design.
Design Considerations
- Choose CEDV intentionally. Do not treat BQ4050 as algorithm-equivalent to an Impedance Track pack manager simply because the surrounding protection features look similar.
- Check whether 10 mA internal balancing meets the pack’s correction-time requirement. Larger packs may need external balancing.
- Coordinate primary and secondary protection thresholds. The FUSE path is intended for more serious permanent-failure conditions and should align with pack fuse hardware.
- Route the coulomb-count shunt with Kelvin connections. Current measurement supports both gauging and protection decisions.
- Plan data-flash programming and authentication during manufacturing. Protection, diagnostics and security depend on correct production configuration.
Product Status and Exact Order Code
Manufacturer status: Active / Production
Texas Instruments lists BQ4050RSMR in the 32-pin VQFN RSM package with a 3000-piece large tape-and-reel carrier, Level-1-260C-UNLIM MSL classification, an operating-temperature listing of −40°C to +85°C, and part marking BQ4050. BQ4050RSMT is the related 250-piece small tape-and-reel option.
Related Engineering Resources
Quality & Verification Support
Third-party inspection or testing can be arranged according to customer requirements. Testing fees are borne by the buyer. Additional verification requirements can be discussed before shipment. After an order is placed, physical product, label, packaging, and Date Code photos may be provided where appropriate.
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