Texas Instruments BQ40Z50RSMR-R1 Battery Pack Manager with Impedance Track Fuel Gauge
The Texas Instruments BQ40Z50RSMR-R1 is a highly integrated 1–4 series cell Li‑ion/Li‑polymer battery pack manager that combines a proven Impedance Track fuel gauge with comprehensive pack protection and control. Housed in a compact 32-pin VQFN (RSM) package and rated for -40°C to +85°C operation, this device is built for smart rechargeable battery packs across portable, industrial, and medical equipment. With SMBus communication, cell balancing control, Turbo Mode 1.0 support (R1 firmware), and safety mechanisms for over/under-voltage, over-current, short-circuit, and temperature, the BQ40Z50RSMR-R1 streamlines design-in and helps accelerate time to market.
The BQ40Z50-R1 family is a go-to choice for engineering teams that need accurate, adaptive state-of-charge (SoC) and state-of-health (SoH) information without sacrificing reliability or board space. For sourcing teams, the BQ40Z50RSMR-R1 part number explicitly denotes the 32-VQFN RSM package, tape-and-reel (“R”), and R1 firmware, reducing ambiguity at procurement.
Fast facts
- Brand/manufacturer: Texas Instruments
- MPN: BQ40Z50RSMR-R1 (BQ40Z50-R1 family, RSM = VQFN-32)
- Series: bq40z50
- Category: Battery Management ICs • Fuel Gauge / Pack Manager
- Battery chemistry: Li-ion / Li-polymer
- Series cell count: 1–4 cells
- Fuel gauge method: Impedance Track
- Interface: SMBus (compatible with I²C physical layer)
- Turbo Mode: 1.0 (R1 firmware)
- Operating temperature: -40°C to +85°C
- Package: VQFN-32 (RSM)
- Packaging: Tape & Reel (TR)
- Mounting type: Surface Mount
- Pin count: 32
- Lifecycle status: Active
- RoHS status: RoHS Compliant (RoHS & Green; Pb-free, halogen free per TI)
Links
- Product page: https://www.ti.com/product/BQ40Z50-R1
- Datasheet: https://www.ti.com/lit/ds/symlink/bq40z50-r1.pdf
Why choose the BQ40Z50RSMR-R1?
Accurate, adaptive fuel gauging with Impedance Track
TI’s Impedance Track technology models the battery’s dynamic impedance to deliver accurate SoC and remaining run-time estimates across load, temperature, and aging. For systems where predictability matters—portable instruments, medical devices, or rugged handhelds—this means fewer unexpected shutdowns and better user experience compared to simplistic coulomb counting alone.
Integrated protection and pack management
The Texas Instruments BQ40Z50RSMR-R1 integrates control and safety features commonly required in multi-cell Li-ion packs. Built-in protections cover over-voltage, under-voltage, over-current, short-circuit, and temperature fault conditions. It also provides cell balancing control to help maintain pack health and capacity over time. This integration reduces the number of external components and simplifies the safety architecture at the pack level.
SMBus for host communication
With a standard SMBus interface, the device communicates key telemetry—voltage, current, temperature, SoC, and alarms—to the host system. SMBus compatibility with the I²C physical layer facilitates broad microcontroller and SoC support, easing firmware integration and enabling diagnostics, logging, and system-level optimization.
Turbo Mode 1.0 (R1)
Turbo Mode 1.0 in the R1 firmware helps coordinate short-duration, higher-power operating intervals while keeping within defined pack safety limits. For systems that occasionally need bursts of performance—spin-up events, compute peaks, or RF power ramps—this feature can enable better responsiveness without oversizing the battery or power path.
Key specifications
Only values published in the provided data are listed below. If a parameter is not shown, it is not specified here and should be confirmed in the datasheet.
- Function: Battery pack manager with fuel gauge and protection
- Battery chemistry: Li-ion / Li-polymer
- Supported series cell count: 1–4 cells
- Fuel gauge method: Impedance Track
- Communications: SMBus (compatible with I²C physical layer)
- Turbo Mode: 1.0 (R1 firmware)
- Operating temperature: -40°C to +85°C
- Package code: RSM (VQFN-32)
- Package: VQFN-32; 32 pins; Surface Mount; Tape & Reel (TR)
- Lifecycle status: Active
- Environmental compliance: RoHS & Green (Pb-free, halogen free per TI)
Not specified in datasheet (confirm requirements in TI documentation):
- Absolute maximum ratings, voltage/current limits
- Fuel gauge accuracy metrics
- Calibration procedures and data flash configuration details
- Cell balancing current and external component sizing
- Specific protection thresholds and timing parameters
System integration overview
Designing a 1–4S smart battery pack around the Texas Instruments BQ40Z50RSMR-R1 typically involves the following elements:
- Series cell stack (1–4 Li-ion/Li-polymer cells)
- Sense resistor for current measurement
- Thermistor(s) for temperature monitoring
- Protection FETs and associated circuitry for charge/discharge path control
- Cell balancing network controlled by the gauge/manager
- SMBus connection to the host system for telemetry and control
The BQ40Z50-R1 acts as the supervisory brain of the pack—measuring voltages, current, and temperatures; maintaining a model of the battery; executing protection logic; and exposing data over SMBus. Cell balancing control helps equalize cell voltages, supporting longevity and usable capacity. The host system can query state-of-charge, remaining run time, and error flags to optimize system behavior (for example, entering a reduced power profile as SoC approaches a defined threshold).
Implementation details—such as FET sizing, balancing resistor values, fuse strategy, connector pinout, and EMC measures—are application dependent and should be selected according to system power requirements and compliance targets. Always refer to TI’s datasheet and application resources for layout recommendations and protection component selection.
Applications and markets
The BQ40Z50RSMR-R1 is suited for a wide range of battery-powered designs that demand accuracy, safety, and compact integration:
- Smart battery packs (1–4S)
- Portable industrial instruments and tools
- Medical and healthcare devices with rechargeable packs
- Test and measurement equipment
- Rugged handhelds, scanners, and specialty consumer devices
- Embedded systems that require SMBus fuel gauging and pack protection
In these applications, accurate SoC/SoH estimation reduces unexpected shutdowns and enables more precise power budgeting, while integrated protections address safety and reliability requirements.
Design and layout considerations
The following high-level considerations can improve results in a multi-cell pack using the Texas Instruments BQ40Z50RSMR-R1. These are general best practices; confirm all specifics with TI documentation and your system requirements.
- Sense path integrity: Keep the current-sense resistor close to the device pins with a tight Kelvin connection and a short, symmetric layout to minimize noise and measurement error.
- Thermistor placement: Place NTC sensors where they best represent cell temperature and hot spots—often near the center of the cell stack or in thermal contact with cells—and consider additional sensors for packs with uneven thermal profiles.
- Cell balancing routing: Use short, well-routed balance lines. Ensure balancing components are sized for thermal and electrical limits defined by the design.
- Grounding: Implement a star-ground or low-impedance ground strategy to maintain measurement accuracy and robust protection operation.
- EMC/ESD: Provide appropriate transient and ESD protection at pack connectors and SMBus lines, adhering to system compliance needs.
Not specified in datasheet: detailed pin functions, recommended layout layers, and example schematics—obtain from the TI datasheet and application notes.
Lifecycle, procurement, and part numbering
- Lifecycle status: Active (per provided data; verify current status on the TI product page)
- Replacements: None specified in the provided data
- Orderable details: “RSM” denotes the 32-pin VQFN package. The trailing “R” indicates tape-and-reel packaging. “-R1” denotes the R1 firmware revision.
- Packaging: Tape & Reel (TR) for automated high-volume assembly
- RoHS/Green: Pb-free, halogen-free per TI
Sourcing tips:
- Confirm that the selected MPN precisely matches your mechanical and firmware needs: BQ40Z50RSMR-R1 for VQFN-32, R1 firmware, tape-and-reel.
- Align the supported series cell count (1–4S) and chemistry (Li-ion/Li-polymer) with your battery selection.
- Validate operating temperature (-40°C to +85°C) against your environmental profile.
- Ensure your host platform supports SMBus and your system software stack can interpret the required fuel-gauging metrics.
- Request the latest compliance statements from TI if your quality system requires documentation beyond RoHS & Green.
Compliance and environmental
- RoHS compliance: RoHS & Green (Pb-free, halogen free per TI)
- Operating temperature: -40°C to +85°C
Not specified in datasheet:
- REACH status, UL/IEC pack certifications, functional safety documentation, or shipping classification; consult TI and your pack manufacturer for regulatory needs.
How it benefits engineering, operations, and sourcing
- Engineering value: Accurate SoC/SoH data via Impedance Track can reduce guard bands and improve run-time predictions, enabling more confident power budgeting and better user experience. Integrated protection and balancing control simplify schematics and firmware.
- Manufacturing value: The compact VQFN-32 (RSM) package and tape-and-reel availability support automated assembly. SMBus compatibility eases test development for end-of-line validation.
- Sourcing value: Clear, unambiguous part numbering (BQ40Z50RSMR-R1) and Active lifecycle status help reduce procurement risk. RoHS & Green compliance aligns with global environmental requirements.
Common questions (FAQ)
Q: How many cells does the BQ40Z50-R1 support?
A: It supports 1 to 4 series-connected Li-ion/Li-polymer cells.
Q: What communication interface is used?
A: The device communicates via SMBus (compatible with the I²C physical layer).
Q: What is Turbo Mode 1.0?
A: Turbo Mode 1.0 is a feature enabled in the R1 firmware that supports system-level performance optimization by coordinating the battery pack and host to allow short-duration higher-power operation within defined limits.
Q: Is the BQ40Z50RSMR-R1 RoHS compliant?
A: Yes. It is RoHS & Green (Pb-free, halogen free per TI).
Q: What package is the BQ40Z50RSMR-R1 available in?
A: VQFN-32 with package code RSM; the “R” in the MPN indicates tape-and-reel packaging.
Q: What is the operating temperature range?
A: -40°C to +85°C.
Q: Does it include cell balancing?
A: It provides cell balancing control as part of the pack management feature set.
What’s not covered here
To keep this page accurate, we only list parameters present in the provided data. For complete electrical characteristics, timing, fuse strategies, programming details, memory maps, and calibration procedures, consult the Texas Instruments datasheet and product documentation:
- Datasheet: https://www.ti.com/lit/ds/symlink/bq40z50-r1.pdf
- Product page: https://www.ti.com/product/BQ40Z50-R1
Summary
The Texas Instruments BQ40Z50RSMR-R1 consolidates fuel gauging, protection, and pack management for 1–4S Li-ion/Li‑polymer designs in a compact, production-ready form factor. Its Impedance Track algorithm supports accurate SoC/SoH estimation, SMBus simplifies host integration, and Turbo Mode 1.0 in the R1 firmware enables short bursts of higher system performance. With an Active lifecycle status and RoHS & Green compliance, the BQ40Z50RSMR-R1 is a strong fit for smart battery packs in portable, industrial, and medical markets—helping teams build reliable products while streamlining sourcing and manufacturing.