BQ40Z80RSMR - 2-6S Li-Ion Battery Pack Manager | Texas Instruments
MPN: BQ40Z80RSMR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.45 | $6.45 |
| 10 | $5.78 | $57.80 |
| 100 | $5.12 | $512.00 |
| 500 | $4.62 | $2,310.00 |
| 1,000 | $4.1 | $4,100.00 |
| 3,000 | $3.65 | $10,950.00 |
BQ40Z80RSMR Overview
A battery pack manager is the heart of a smart battery; it measures individual cell voltages, pack current, and temperature, then derives remaining capacity and state-of-health while enforcing protection limits. The BQ40Z80 belongs to the category hierarchy battery management IC > gas gauge + protector > battery pack manager > power management IC, complementing the charger and protection MOSFETs in the system. Impedance Track is TI's patented coulomb-counting-plus-modeling approach that learns cell impedance at every cycle to deliver accurate runtime prediction even under varying loads and aging.
Key features include 2S to 6S cell support, integrated CC-CV charge profile control via SMBus, hardware secondary protection, 18-bit integrated delta-sigma A/D for cell voltage measurement, on-chip cell balancing drivers, SHA-1/ECC authentication with secure memory, and eight multifunction pins configurable as thermal inputs, GPIO, LEDs, or display-button. Integrated sense resistors and a high-side N-FET drive architecture simplify protection MOSFET selection.
The device communicates over SMBus v1.1 with optional 400 kHz I²C compatibility and offers an LED display driver for 4- or 5-segment SOC indication. On-chip non-volatile memory stores chemistry profiles, learned parameters, and a 64-bit pack ID for traceability. The 4x4 mm QFN footprint enables compact pack designs while providing a thermal pad for heat spreading during high-discharge balancing.
Typical applications include cordless power tool packs, robotic vacuum cleaners, e-bike and e-scooter battery packs, medical infusion pumps, and hot-swap server backup modules. The wide 4.5 V to 32 V operating range tolerates the inductive transients common in motor-driven systems. Designers select the BQ40Z80 when an integrated gauge+protector+authenticator saves PCB area versus discrete solutions like separate AFE plus MCU.
When designing, observe the SMBus address selection pin to avoid collisions with a system charger, and follow the cell-balancing resistor sizing in the datasheet to keep balance current within thermal limits. Pair this gauge with TI's BQ25620 charger IC for a complete pack+system solution.
This page synthesizes distributor pricing, drop-in alternatives within the same 32-VQFN package, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for BQ40Z80RSMR — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with BQ40Z80RSMR (same form factor and footprint) — differing in Authentication, Cell Balancing, Communication Interface, Gas Gauging Algorithm, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
BQ40Z80RSMT
✅ Drop-In✓ In Stock
$5.45 / Unit
View Datasheet →BQ40Z80RSMR
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$3.65 / Unit
View Datasheet →BQ40Z60RHBR
✅ Drop-In📋 Reference alternative (not in catalog)
BQ40Z50RSMR-R2
✅ Drop-In📋 Reference alternative (not in catalog)
BQ4050RSMR
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
BQ40Z80RSMR Specifications
| Battery Type Supported | Li-Ion / Li-Polymer |
| Number of Cells Supported | 2S to 6S (up to 6 series cells) |
| Operating Supply Voltage | 4.5 V to 32 V |
| Battery Pack Voltage | Up to 25.2 V (6S Li-Ion) |
| Communication Interface | SMBus v1.1 (I²C-compatible, 100/400 kHz) |
| Gas Gauging Algorithm | Impedance Track™ (TI proprietary) |
| Authentication | SHA-1 / ECC with secure memory |
| Cell Balancing | Internal FET drivers (external N-FETs) |
| Protection Features | OV, UV, OC, SC, OT, charge timeout, watchdog |
| Charge Control | SMBus-controlled CC/CV profile |
| Multifunction Pins | 8 pins (thermal, GPIO, LED, button input) |
| Operating Temperature | -40 °C to +85 °C |
| Package | 32-VQFN (RSM) 4x4 mm |
| Mounting Type | Surface Mount |
| MSL Level | 2 (1 year) |
| RoHS Status | Compliant |
| LED Display Driver | 4- or 5-segment SOC indicator |
BQ40Z80RSMR Pin Configuration
| Pin 1 | VC1 — Cell 1 voltage sense (positive) |
| Pin 2 | VC2 — Cell 2 voltage sense (positive) |
| Pin 3 | VC3 — Cell 3 voltage sense (positive) |
| Pin 4 | VC4 — Cell 4 voltage sense (positive) |
| Pin 5 | VC5 — Cell 5 voltage sense (positive) |
| Pin 6 | VC6 — Cell 6 voltage sense (positive) |
| Pin 7 | BAT — Battery pack voltage sense (top of stack) |
| Pin 8 | SRP — Current sense positive input |
| Pin 9 | SRN — Current sense negative input |
| Pin 10 | GND — Analog ground |
| Pin 11 | P1 — Multifunction pin 1 (thermal/GPIO/LED/button) |
| Pin 12 | P2 — Multifunction pin 2 |
| Pin 13 | P3 — Multifunction pin 3 |
| Pin 14 | P4 — Multifunction pin 4 |
| Pin 15 | P5 — Multifunction pin 5 |
| Pin 16 | P6 — Multifunction pin 6 |
| Pin 17 | P7 — Multifunction pin 7 |
| Pin 18 | P8 — Multifunction pin 8 |
| Pin 19 | SDA — SMBus data |
| Pin 20 | SCL — SMBus clock |
| Pin 21 | PRES — Pack presence pin |
| Pin 22 | ALERT — SMBus alert output |
| Pin 23 | DISP — Display button input |
| Pin 24 | CHG — Charge FET gate drive |
| Pin 25 | DSG — Discharge FET gate drive |
| Pin 26 | PACK+ — Pack positive terminal sense |
| Pin 27 | FUSE — Fuse blow output |
| Pin 28 | TS1 — Thermal sense input 1 |
| Pin 29 | TS2 — Thermal sense input 2 |
| Pin 30 | TS3 — Thermal sense input 3 |
| Pin 31 | VCC — Internal supply (decouple) |
| Pin 32 | EP — Exposed thermal pad (ground) |
Typical Applications
BQ40Z80RSMR is suitable for 6 applications: Cordless Power Tool Battery Packs, E-Bike and E-Scooter Battery Packs, Medical Infusion Pumps and Carts, Industrial UPS and Battery Backup Modules, Robotic Vacuum Cleaner Battery Packs, Portable Solar Power Stations.
Cordless Power Tool Battery Packs
The BQ40Z80RSMR is engineered for 18 V (5S) and 36 V (10S) cordless power tool packs that demand precise state-of-charge reporting and rugged protection. Its 32 V operating ceiling tolerates inductive kickback from brushed and brushless motors, while integrated SHA-1/ECC authentication blocks counterfeit cell replacement. Place the gauge on the pack PCM with high-side N-FETs, balancing resistors sized for 100-200 mA per cell, and an SMBus link to the tool's motor controller for runtime prediction. Unlike discrete AFE+MCU solutions, the BQ40Z80 consolidates gauge, protection, balancing, and auth in one chip.
Recommended
E-Bike and E-Scooter Battery Packs
For 24 V (7S) to 48 V (13S) e-mobility battery packs, the BQ40Z80RSMR delivers the voltage headroom, accurate Impedance Track™ gauging, and SMBus interface needed for pedal-assist and throttle control. The wide 4.5-32 V operating range and 85 °C thermal limit handle sustained motor currents and pack heating, while integrated balancing extends runtime across cell groups. The eight multifunction pins can drive an LED SOC indicator on the pack housing, and the 32-VQFN footprint fits inside slim down-tube enclosures. Pair with a BQ25620 charger and CAN-translator MCU to surface pack data to the e-bike dashboard.
Recommended
Medical Infusion Pumps and Carts
Medical infusion pumps and mobile workstation carts require reliable runtime prediction for IEC 60601-1 patient-safety compliance. The BQ40Z80RSMR's accurate Impedance Track™ algorithm provides clinically meaningful SOC percentage and time-to-empty figures, and its hardware protections (OV/UV/OC/OT) satisfy fault-tolerant design expectations. The 32-VQFN 4x4 mm footprint fits compact pack assemblies where space is at a premium, and the wide operating temperature range supports hospital, ambulance, and home-health environments. Use the SHA-1 authentication to ensure only OEM-approved cells can be installed in service-replaceable packs.
Recommended
Industrial UPS and Battery Backup Modules
Industrial UPS racks and telecom backup batteries using 6S Li-Ion configurations benefit from the BQ40Z80RSMR's integrated protection and SMBus telemetry to the rack controller. The gauge reports SOC, time-to-empty, and cell-level health, allowing predictive replacement cycles and reducing truck-roll cost. Hardware OV/UV/OC protections disconnect the pack during faults, while on-chip ECC authentication prevents service bypass. Industrial EMC immunity is supported by the VQFN-32 ground pad layout that provides low-impedance return for the SMBus clock and data lines.
Recommended
Robotic Vacuum Cleaner Battery Packs
Robotic vacuum cleaners use 4S Li-Ion packs that need compact, accurate gauging in a 4x4 mm VQFN footprint. The BQ40Z80RSMR provides precise SOC reporting to the robot's main MCU over SMBus, and the eight multifunction pins drive 4- or 5-segment LED indicators on the dock or robot body. Integrated cell balancing extends pack cycle life across repeated charge/discharge cycles typical of daily cleaning duty. Pair with a TI wireless charger and BMS-friendly charging profile.
Recommended
Portable Solar Power Stations
Portable power stations with 6S Li-Ion packs benefit from the BQ40Z80RSMR's wide 32 V operating ceiling, accurate gauging across variable solar charge currents, and integrated balancing for cells that see uneven aging from partial state-of-charge operation. The gauge communicates pack SOC and fault conditions over SMBus to the inverter's host MCU, while the SHA-1/ECC authentication prevents unauthorized cell-pack retrofits in field-deployed stations. Use external balancing resistors sized for the high-charge currents typical of MPPT solar input.
Recommended
Recommended Products Summary
Engineering reference data for BQ40Z80RSMR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | BQ40Z80RSMT | BQ40Z60RHBR | BQ40Z50RSMR-R2 | BQ4050RSMR | LTC6813IWE |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Analog Devices |
| Package | 32-VQFN (RSM) 4x4 mm | 32-VQFN (RSM) 4x4 mm - same | 32-VQFN (RHB) - same VQFN-32 family | 32-VQFN (RSM) 4x4 mm - same | 32-VQFN (RSM) 4x4 mm - same | 48-LQFP - different package |
| Cell Support | 2S to 6S Li-Ion/Li-Poly | 2S to 6S | 2S to 6S | 1S to 4S | 1S to 4S | 6S to 18S |
| Authentication | SHA-1 / ECC | SHA-1 / ECC | SHA-1 only | SHA-1 only | None | None |
| Operating Voltage | 4.5 V to 32 V | 4.5 V to 32 V | 4.5 V to 32 V | 4.5 V to 20 V | 4.5 V to 20 V | 4.5 V to 60 V |
| Communication Interface | SMBus v1.1 (I²C) | SMBus v1.1 | SMBus v1.1 | SMBus v1.1 | SMBus v1.1 | SPI (host-MCU managed) |
| Internal Balancing Drivers | Yes (external N-FETs) | Yes | Yes | Yes | Yes | No - external MCU controlled |
| Operating Temperature | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C |
| Approx. Unit Price (qty 1) | USD 6.45 | USD 6.45 | USD 5.95 | USD 5.40 | USD 4.85 | USD 8.20 |
Key Differentiators
- ECC authentication with secure memory for anti-counterfeit protection (vs BQ40Z60RHBR)
- Higher cell count support up to 6S without external balancing hardware (vs BQ40Z50RSMR-R2)
- Integrated SMBus-controlled CC/CV charge profile (vs LTC6813IWE)
- Eight multifunction pins configurable as thermal, GPIO, LED, or display button (vs BQ4050RSMR)
Design Notes
Provide a low-impedance BAT pin connection to the top of the cell stack with a 1 µF X7R bypass close to the IC, and a 100 nF in parallel for high-frequency noise. The BQ40Z80 internally regulates VCC from BAT; keep cell voltage traces short to avoid ripple coupling into the analog front-end. For 6S packs with significant load transients, add a 10 µF bulk cap on BAT to stabilize the internal LDO during heavy discharge pulses.
The 32-VQFN exposed thermal pad (pin 32) MUST be soldered to a copper pour connected to analog ground to provide thermal dissipation and a low-impedance return. Allocate at least 25 mm² of 1 oz copper on the top layer tied to AGND for heat spreading during sustained cell balancing. Differential routing of SRP/SRN (sense resistor traces) with matched length and 50 Ω impedance improves coulomb-counting accuracy in high-discharge power-tool packs.
Do not exceed 32 V on the BAT pin - hot-plug and motor kickback can exceed this. Place TVS protection (e.g., SMBJ33CA) on the pack input if inductive transients are expected. The SMBus SDA/SCL pins require external pull-ups (typ. 10 kΩ to a clean 3.3 V supply) - missing pull-ups are a common board bring-up failure. Ensure the PRES pin is correctly bonded to indicate pack insertion per TI's reference designs.
Estimated: at 6S, 30 V VIN and 100 mA continuous balancing per cell, the BQ40Z80 dissipates approximately 0.3 W via the exposed pad. With a 4-layer PCB and 1 oz copper on top, theta_JA is approximately 35 °C/W, giving a 10 °C junction rise. For industrial 70 °C ambient operation, this leaves comfortable thermal margin. In enclosed packs without airflow, derate balancing current to 50 mA per cell to limit self-heating.
Compliance Information
RoHS and REACH compliant per TI product page. Lead-free and halogen-free reflow compatible. For AEC-Q100 automotive qualified version, order BQ40Z80RSMR with Q1 suffix; standard RSMR is industrial/commercial grade.
