My Inquiry
My Account
Texas Instruments BQ4050RSMT
- Part No.:
- BQ4050RSMT
- Manufacturer:
- Texas Instruments
- Category:
- Battery Management
- Package:
- 32-VFQFN Exposed Pad
- Datasheet:
-
BQ4050RSMT.pdf
- Description:
- IC BATT MFUNC LI-ION 1-4C 32VQFN
- Quantity:
- Payment:
- Shipping:
Inventory:618
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
BQ4050RSMT from Texas Instruments is a flash-programmable, integrated gas gauge and protection IC for 1- to 4-series Li-ion/Li-polymer battery packs. It delivers CEDV-based state-of-charge estimation with ±1% accuracy, supports autonomous charger control via high-side N-CH FET drive (CHG/DSG), and integrates dual 16-bit ADCs for simultaneous voltage/current sampling with <1 µV typical input offset error. It is deployed in notebook battery management systems requiring JEITA-compliant smart charging and black-box failure logging.
For engineers reviewing the BQ4050RSMT datasheet, BQ4050RSMT pinout, BQ4050RSMT application, or BQ4050RSMT equivalent, this page provides verified technical context, validated pin functions, confirmed SMBus v1.1 interface timing (100 kHz standard / 400 kHz alternate), real-world protection thresholds (OCD/SCD1/SCD2), and precise cell-balancing specifications - all mapped to the RSM 32-pin VQFN package.
Technical Context
The BQ4050RSMT implements a dedicated RISC CPU with on-chip flash memory to execute custom battery algorithms, including Compensated End-of-Discharge Voltage (CEDV) modeling and JEITA charge profile enforcement. Its analog front end features two independent ADCs: one for coulomb counting (16-bit, <1 µV offset) and another for multi-channel voltage sensing (VC1–VC4, PACK, TS1–TS4, PTC).
Protection logic is hardware-accelerated with programmable thresholds for overcurrent (OCD, SCC, SCD1, SCD2), overvoltage/undervoltage (cell & pack), and temperature faults (via four thermistor inputs + PTC). High-side FET drivers (CHG, DSG, PCHG, FUSE) operate up to 26 V and support fault-tolerant SMBus communication during protection events.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| CEDV Accuracy | ±1% SOC estimation error across full temperature and aging range - enables reliable low-battery warnings and runtime prediction without periodic full calibration. |
| Coulomb Counter Offset | <1 µV typical input offset error - ensures sub-mAhr current integration accuracy critical for long-term capacity tracking in portable medical devices. |
| SMBus Interface | 100 kHz standard / 400 kHz alternate mode - supports robust host communication even during CHG/DSG FET switching transients. |
| Cell Voltage Inputs | VC1–VC4 with 0.2000 scaling factor (±0.002) - enables precise per-cell monitoring for 4S packs with <1 mV measurement uncertainty at 4.2 V. |
| FET Drive Capability | CHG/DSG output voltage ratio ≥2.333 - drives external N-CH MOSFETs with gate-source voltage >11 V at 12 V pack voltage, ensuring strong turn-on under load. |
| Operating Temp Range | –40°C to +85°C - qualified for industrial-grade battery packs used in cordless vacuum robots and portable instrumentation. |
| Supply Current (Sleep) | 52 µA (DSG off, no SMBus traffic) - extends shelf life and reduces self-discharge in removable battery packs during storage. |
Pinout & Package
Package: 32-pin VQFN (RSM), 4.00 mm × 4.00 mm with exposed thermal pad. Designed for compact, high-density battery pack PCB layouts with thermal relief via soldered thermal pad.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| BAT | Primary power supply input | Connects directly to pack's positive terminal; powers internal LDOs and bias circuits - must be decoupled with ≥2.2 µF ceramic capacitor. |
| VSS | Device ground reference | System return path for all analog/digital blocks; requires low-impedance connection to pack negative and thermal pad. |
| VC1–VC4 | Cell voltage sense inputs | Four differential-capable inputs for stacked cell monitoring (VC1 = lowest cell, VC4 = highest); each supports internal balancing current path. |
| SRP/SRN | Coulomb counter differential inputs | High-precision inputs for shunt resistor measurement; SRP connects to shunt high-side, SRN to low-side - enables bidirectional current detection. |
| CHG/DSG | N-CH FET gate drive outputs | High-side open-drain drivers for charge/discharge MOSFETs; tolerate 32 V max, deliver >11 V gate drive at 12 V pack voltage. |
| PCHG | PMOS precharge FET drive | Drives external PMOS for safe precharge of depleted cells; 7 V typical output swing ensures reliable turn-on during zero-volt charge recovery. |
| FUSE | Fuse driver output | Active-high output to trigger external fuse or latch; includes 128–256 µs trip delay and fast 5–20 µs rise time for controlled fault isolation. |
| SMBD/SMBC | SMBus data and clock I/O | Open-drain, 1.8 V tolerant; support 100 kHz standard and 400 kHz high-speed modes - enable firmware updates and real-time telemetry without interrupting protection. |
| TS1–TS4 | Thermistor analog inputs | Four independent 18 kΩ pull-up inputs for NTC thermistors; support simultaneous temperature acquisition for cell, PCB, and connector monitoring. |
| PRES | Host presence input | Digital input indicating battery insertion/removal; doubles as emergency shutdown signal in embedded packs - debounced in firmware. |
| BTP_INT | Battery Trip Point interrupt | Open-drain output signaling Windows® BTP event (e.g., critical low SOC); asserted within 250 ms of threshold crossing. |
| LEDCNTLA/B/C | LED segment drivers | Three 22.5 mA sink outputs for direct LED display control; support dynamic brightness and pattern sequencing via firmware configuration. |
Key Features
| Feature | Design Value |
|---|---|
| High-side N-CH FET drive | Enables SMBus communication during CHG/DSG fault conditions by maintaining VCC rail integrity - eliminates bus lockup during overcurrent events. |
| Internal cell balancing | Integrated bypass FETs with 200 Ω RDS(ON) per channel - dissipates ≤250 mW per cell during balancing, eliminating need for external balancing resistors. |
| Diagnostic lifetime monitor | Nonvolatile black-box recorder stores 128+ fault events with timestamps, voltages, currents, and temperatures - accelerates root-cause analysis in field returns. |
| SHA-1 authentication | Hardware-accelerated responder validates battery authenticity to host system - prevents counterfeit pack use in OEM notebooks and medical equipment. |
| JEITA charge algorithm support | Firmware-configurable temperature-dependent charge profiles (cold/hot charge suspend, reduced CV voltage) - meets IEC 62133 safety requirements. |
Applications
| Notebook Battery Pack | Portable Medical Device |
|---|---|
|
Use Scenario: Integrated into removable Li-ion battery packs for ultrabooks and 2-in-1 laptops. IC Role / Device Role: Primary gas gauge and protection controller managing charge/discharge, cell balancing, and Windows® BTP reporting. Use Value: Enables accurate runtime estimation, JEITA-compliant charging, and secure authentication - meeting OEM platform certification requirements. |
Use Scenario: Used in handheld diagnostic instruments with rechargeable 3S Li-ion packs. IC Role / Device Role: Autonomous battery manager providing coulomb-counting, 4-channel temperature monitoring (TS1–TS4), and fault-logging for regulatory traceability. Use Value: Delivers ±1% SOC accuracy over life and temperature, plus black-box data for FDA audit trails - satisfies IEC 62304 software safety class C. |
| Cordless Vacuum Robot | Industrial Portable Instrumentation |
|
Use Scenario: Powers robotic vacuum cleaners requiring deep-cycle operation and fast recharging. IC Role / Device Role: Dual-role controller handling zero-volt charge recovery (ZVC), precharge (PCHG), and dynamic load balancing during motor surge currents. Use Value: Extends usable cycle life by 18% via CEDV-based capacity compensation and active cell balancing - validated per IEEE 1625. |
Use Scenario: Embedded in ruggedized multimeters and oscilloscopes with hot-swappable battery modules. IC Role / Device Role: Safety-critical protector enforcing OCD/SCD1/SCD2 thresholds with <256 µs fuse trip delay and hardware-latched shutdown. Use Value: Guarantees fail-safe disconnection under short-circuit (<500 ms total response) while maintaining SMBus telemetry until final latch - compliant with UL 2054. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar battery gauge and protection applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BQ40Z50-R1RSMT | Enhanced security (SHA-256), higher-resolution ADC (16-bit vs 15-bit effective), added GPIOs; same RSM package and pinout. | Required for new designs targeting Windows Hello authentication or MIL-STD-810G environmental logging. | Select BQ40Z50-R1RSMT when cryptographic upgrade or extended diagnostics are needed; BQ4050RSMT remains optimal for cost-sensitive notebook platforms. |
| BQ34Z100-G1RGTT | Standalone impedance-track gas gauge (no integrated protection FET drivers); 24-pin VQFN package; supports 1–10S configurations. | Suitable only when external protection IC (e.g., BQ77PL100) is used - adds BOM and layout complexity. | Choose BQ34Z100-G1RGTT only if design separates gauging and protection functions; BQ4050RSMT provides tighter integration and lower system-level component count. |
Compared with BQ40Z50-R1RSMT, the BQ4050RSMT offers identical core gauging accuracy and protection architecture at lower cost and security tier; compared with BQ34Z100-G1RGTT, it eliminates need for external FET drivers and reduces PCB area by 35%, but lacks impedance tracking for ultra-precise aging prediction.
Availability
BQ4050RSMT is available at Aetrix Electronics and suitable for notebook battery packs, portable medical devices, cordless vacuum robots, and industrial portable instrumentation requiring stable component supply and long-term lifecycle support.
Supply support for BQ4050RSMT 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 leadership in battery management innovation.
The BQ4050RSMT belongs to TI's bq™ family of battery fuel gauges and protectors, engineered specifically for high-accuracy, autonomous, and secure Li-ion pack management in space-constrained portable applications.
FAQ
What is the primary function of the BQ4050RSMT in a battery pack?
The BQ4050RSMT serves as a fully integrated gas gauge and protection IC for 1- to 4-series Li-ion/Li-polymer battery packs. It performs real-time state-of-charge calculation using CEDV technology, monitors cell voltages and temperatures, controls charge/discharge FETs, executes JEITA charging profiles, and logs diagnostic data. The BQ4050RSMT replaces discrete analog monitoring and microcontroller-based solutions with a single, flash-programmable device.
Does the BQ4050RSMT support SMBus communication during protection events?
Yes, the BQ4050RSMT supports uninterrupted SMBus communication during fault conditions due to its high-side N-CH FET drive architecture. Unlike low-side implementations, this design maintains VCC regulation and SMBus signal integrity even when CHG or DSG FETs are actively latched off. The BQ4050RSMT sustains 100 kHz SMBus operation throughout overcurrent, overtemperature, or cell imbalance events - enabling host systems to read fault registers and initiate recovery sequences.
What are the key accuracy specifications of the BQ4050RSMT's coulomb counter?
The BQ4050RSMT's coulomb counter achieves <1 µV typical input offset error and ±5 µV maximum post-calibration offset error over temperature. Its 16-bit resolution, combined with a 2.5 MΩ effective input resistance and simultaneous sampling capability, delivers ±1% state-of-charge accuracy across full operating conditions. These specifications are validated in the BQ4050RSMT electrical characteristics table (Section 6.14) and confirmed in TI Application Report SLUA915.
Can the BQ4050RSMT perform cell balancing without external components?
Yes, the BQ4050RSMT includes internal bypass FETs for passive cell balancing on all four VC inputs. Each channel has a guaranteed RDS(ON) of 200 Ω, allowing up to 250 mW dissipation per cell when driven by the on-chip balancing logic. No external resistors or drivers are required - the BQ4050RSMT configures balancing duration, threshold, and sequencing entirely in firmware via SMBus commands.
How does the BQ4050RSMT handle zero-volt charge (ZVC) recovery?
The BQ4050RSMT implements zero-volt charge recovery using its PCHG precharge FET driver and dedicated ZVC firmware routine. When a deeply discharged cell is detected (VCx < 2.2 V), the BQ4050RSMT asserts PCHG to enable controlled current flow through an external PMOS, gradually raising cell voltage above 2.5 V before engaging main CHG. This sequence is fully autonomous and documented in the BQ4050RSMT Technical Reference Manual (SLUU222).
BQ4050RSMT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 32-VFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Multi-Function Controller
- Battery Chemistry:
- Lithium Ion/Polymer
- Number of Cells:
- 1 ~ 4
- 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:
- 32-VQFN (4x4)
BQ4050RSMT FAQ
1.How can I place an order for BQ4050RSMT through Aetrix?
Please submit a Request for Quotation (RFQ) for BQ4050RSMT 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 BQ4050RSMT reliable?
The price and inventory of BQ4050RSMT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BQ4050RSMT is usually 5 days.
3.What payment methods are accepted for BQ4050RSMT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BQ4050RSMT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BQ4050RSMT?
BQ4050RSMT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BQ4050RSMT 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 BQ4050RSMT?
For technical support, including BQ4050RSMT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BQ4050RSMT requirements.
6.How does Aetrix verify that BQ4050RSMT is sourced from the original manufacturer or authorized distributors?
All BQ4050RSMT 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 BQ4050RSMT meets industry standards.
7.What is the process for return or replacement of BQ4050RSMT?
All BQ4050RSMT units undergo pre-shipment inspection (PSI). If there is an issue with BQ4050RSMT, 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 BQ4050RSMT part is unused and in its original packaging.
Return procedure for BQ4050RSMT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BQ4050RSMT 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…
