BQ7791506PWR - 3-5S Ultra-Low Power Primary Protector | TI
MPN: BQ7791506PWR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.42 | $2.42 |
| 10 | $2.18 | $21.80 |
| 100 | $1.95 | $195.00 |
| 500 | $1.74 | $870.00 |
| 1,000 | $1.55 | $1,550.00 |
| 2,000 | $1.41 | $2,820.00 |
BQ7791506PWR Overview
Key specifications include an operating temperature range of -40°C to +85°C, scalable cell count from 3S to 5S in standalone mode (extensible via stacking), and autonomous smart passive cell balancing that removes cell-to-cell imbalance without external MCU intervention. The integrated protection set covers overvoltage, undervoltage, overcurrent in discharge, short circuit in discharge, and overtemperature, providing a complete hardware safety layer that complements secondary gas gauges such as the BQ27421-G1.
The BQ7791506PWR uses an analog front-end plus dedicated hardware comparators with user-configurable thresholds via external resistors. Autonomous cell balancing fires when the delta between the highest and lowest cell exceeds a programmable offset, dissipating energy through external resistors until the cells converge. Stackability allows two devices to handle 6S to 10S packs without firmware changes. This hardware-only design means no firmware is required at the host, which reduces BOM complexity and improves functional safety certification paths.
Typical applications include power tools, e-bikes, vacuum cleaners, robotic vacuum cleaners, e-mobility scooters, and uninterruptible power supplies where a dedicated hardware protector is preferred over an integrated fuel gauge. The HIBERNATE pin allows the host to force the device into sub-3 µA quiescent to extend shelf life of stored packs. Compared to fully integrated monitor-and-protect fuel gauges, the BQ7791506 leaves fuel gauging to a dedicated IC and focuses solely on the primary safety function.
When designing with this device, always validate the sense resistor and cell-balancing resistor thermal budgets against the worst-case continuous balancing current. Use Kelvin-sense routing at the high-current ground return, and keep the cell-balancing traces wide enough to handle the programmed balancing current.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for BQ7791506PWR — 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 BQ7791506PWR (same form factor and footprint) — differing in Communication Interface, Function, Operating Temperature Range, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
BQ7791505PWR
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
BQ7791507PWR
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
BQ77915
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
BQ7791500PWR
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$1.02 / Unit
View Datasheet →BQ7791503PWR
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
BQ7791506PWR Specifications
| Function | Primary Battery Protector with Autonomous Cell Balancing |
| Cell Chemistry Supported | Lithium Ion / Lithium Polymer |
| Number of Cells (Standalone) | 3 to 5 series |
| Stackable Cell Count | Up to 10 series (two devices stacked) |
| Quiescent Current - NORMAL | 8 µA (typical) |
| Quiescent Current - HIBERNATE | 2 µA (typical) |
| Cell Balancing | Autonomous smart passive balancing |
| Protection Features | Overvoltage, Undervoltage, Overcurrent Discharge, Short-Circuit Discharge, Overtemperature |
| Operating Temperature Range | -40°C to +85°C |
| Package | 24-pin TSSOP (PW) |
| Mounting Type | Surface Mount |
| MSL Level | 2 |
| Lead-Free / RoHS | Yes (per TI product page) |
| Communication Interface | Hardware-only (no I2C/SPI required for protection) |
BQ7791506PWR Pin Configuration
| Pin 1 | VC5 — Cell 5 voltage sense |
| Pin 2 | VC4 — Cell 4 voltage sense |
| Pin 3 | VC3 — Cell 3 voltage sense |
| Pin 4 | VC2 — Cell 2 voltage sense |
| Pin 5 | VC1 — Cell 1 voltage sense |
| Pin 6 | VC0 — Pack negative / ground reference |
| Pin 7 | BAT — IC supply / top of stack |
| Pin 8 | PACK+ — Pack positive terminal sense |
| Pin 9 | PACK- — Pack negative terminal sense |
| Pin 10 | SCD — Short-circuit sense input |
| Pin 11 | OCD — Overcurrent sense input |
| Pin 12 | HIBERNATE — Force low-Iq mode (active high) |
| Pin 13 | TEMP — Temperature sense input |
| Pin 14 | CHG — Charge FET gate driver |
| Pin 15 | DSG — Discharge FET gate driver |
| Pin 16 | PRES — System-present signal |
| Pin 17 | BAL1 — Balance output for cell 1 |
| Pin 18 | BAL2 — Balance output for cell 2 |
| Pin 19 | BAL3 — Balance output for cell 3 |
| Pin 20 | BAL4 — Balance output for cell 4 |
| Pin 21 | BAL5 — Balance output for cell 5 |
| Pin 22 | GND — IC ground |
| Pin 23 | STK — Stack interface |
| Pin 24 | NC — Not connected (per datasheet) |
Typical Applications
BQ7791506PWR is suitable for 6 applications: Cordless Power Tool Battery Packs, E-Bike and Pedelec Battery Packs, Robotic Vacuum and Floor-Cleaning Appliances, Uninterruptible Power Supplies (UPS) and Backup Battery, Portable Medical Cart and Diagnostic Battery Packs, E-Mobility Scooter and Personal Transport Packs.
Cordless Power Tool Battery Packs
The BQ7791506PWR is well-suited for 3S-5S Li-Ion battery packs in cordless drills, impact drivers, and saws. Its 8 µA NORMAL quiescent and 2 µA HIBERNATE Iq extend tool shelf life on the charger between uses. The autonomous hardware OVP/UVP/SCD/OTD protection meets UL 2054 and IEC 62133 functional-safety expectations without MCU firmware, simplifying certification. Designers pair it with a separate fuel gauge (e.g., BQ27421-G1) and connect the HIBERNATE pin to the gauge ALERT line so the pack can enter deep-sleep when stored. Compared to fully integrated fuel-gauge/protector ICs, the BQ7791506PWR keeps the safety function isolated on its own silicon, which auditors typically prefer for functional-safety documentation.
Recommended
E-Bike and Pedelec Battery Packs
For e-bike and pedelec battery packs the BQ7791506PWR provides 3S-5S protection with stacking support to 10S, covering the most common 36V and 48V e-bike architectures. The autonomous passive cell balancing mitigates cell drift in large-format 18650/21700 packs where imbalance accumulates over many cycles. Its 2 µA HIBERNATE mode is critical because e-bike packs sit idle for weeks between rides - lower Iq translates directly to longer shelf life and reduced warranty returns. The hardware-only protection layer also tolerates the harsh EMI environment of the motor controller, since there is no firmware to lock up under RF injection.
Recommended
Robotic Vacuum and Floor-Cleaning Appliances
Robotic vacuums and cordless floor cleaners run 4S Li-Ion packs that cycle hundreds of times per year under high C-rate discharge. The BQ7791506PWR's autonomous passive balancing keeps the pack matched under frequent partial cycles, while its OCP and SCD thresholds safeguard against stalled-motor inrush currents that can exceed 50 A transiently. The -40°C to +85°C operating range covers both the cold-storage warehouse and hot-summer-floor thermal stress. Designers route PACK- through a low-side shunt so the SCD comparator trips within microseconds of a locked-rotor event, preventing FET avalanche damage.
Recommended
Uninterruptible Power Supplies (UPS) and Backup Battery
Low-power UPS modules for routers, IoT gateways, and home security panels typically use 3S-4S Li-FePO4 or Li-Ion backup packs that float at full charge for months. The BQ7791506PWR's autonomous passive cell balancing handles the subtle imbalance that develops during float charging, while its 8 µA Iq is acceptable when the host is line-powered but the pack must remain self-protected. When mains is lost, the device instantly allows discharge through the DSG FET, and its SCD comparator trips if a downstream short occurs in the failed-grid scenario. The lack of required firmware makes the protection path fully deterministic and easier to certify for residential safety standards.
Recommended
Portable Medical Cart and Diagnostic Battery Packs
Medical carts, infusion pumps, and portable diagnostic devices rely on 3S-4S Li-Ion packs that must meet IEC 60601-1 isolation and leakage requirements. The BQ7791506PWR's hardware-only protection architecture gives auditors a deterministic safety layer that does not depend on MCU firmware, simplifying 60601-1 submission. The autonomous passive balancing keeps the cells matched across thousands of low-current cycles typical of medical duty profiles. Designers place the IC near the battery terminals with Kelvin-sense routing at the high-current ground return to preserve SCD trip accuracy. The -40°C to +85°C range covers refrigerated drug-storage applications as well.
Recommended
E-Mobility Scooter and Personal Transport Packs
E-mobility scooters and last-mile personal transport use 5S-10S Li-Ion packs where the BQ7791506PWR can be stacked to cover up to 10S. The hardware OVP/UVP/SCD protections are critical because a locked motor at startup can momentarily demand 2-3x the rated current, and the SCD trip must act in microseconds to prevent FET damage. The autonomous passive balancing handles the slow cell drift seen in packs that are partially charged for days between rides. Designers typically pair this protector with a high-side N-channel FET driver and a current-sense amplifier for telemetry, while the BQ7791506PWR handles the safety-MOSFET control directly.
Recommended
Recommended Products Summary
Engineering reference data for BQ7791506PWR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | BQ7791505PWR | BQ7791507PWR | BQ77915 | BQ7791500PWR | BQ7791503PWR |
|---|---|---|---|---|---|---|
| Package | TSSOP-24 (PW) | TSSOP-24 (PW) - same | TSSOP-24 (PW) - same | TSSOP-24 (PW) - same | TSSOP-24 (PW) - same | TSSOP-24 (PW) - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Cell Count | 3S to 5S | 3S to 5S | 3S to 5S | 3S to 5S | 3S to 5S | 3S to 5S |
| Quiescent Current (NORMAL) | 8 µA | 8 µA | 8 µA | 8 µA | 8 µA (typ) | 8 µA |
| Quiescent Current (HIBERNATE) | 2 µA | 2 µA | 2 µA | 2 µA | 2 µA (typ) | 2 µA |
| Autonomous Cell Balancing | Yes (passive) | Yes (passive) | Yes (passive) | Yes (passive) | Yes (passive) | Yes (passive) |
| 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 |
Key Differentiators
- Hardware-only autonomous protection with no MCU firmware required (vs BQ7694204PFBR)
- Ultra-low HIBERNATE quiescent of 2 µA typical (vs BQ7791500PWR (earlier gen))
- Stackable to 10S without firmware changes (vs BQ7791503PWR)
Design Notes
Estimated: at continuous 50 mA balance current per cell with 0.5 Ω balancing resistor, each cell dissipates approximately P = I^2 × R = 0.0025^2 × 0.5 = 3.1 mW; at higher balance currents up to 100 mA, dissipation rises to ~5 mW, which is negligible. However the charge (CHG) and discharge (DSG) FETs external to the IC carry full pack current, so their thermal design (RθJA and copper area) dominates the thermal budget. The TSSOP-24 PW package itself dissipates only the IC quiescent losses, so no heatsink is needed.
Place the BQ7791506PWR as close to the battery terminals as practical and use a 4-layer PCB with a continuous ground pour beneath the IC. Route VC1-VC5 sense traces as differential pairs with a ground guard on both sides to reject switching noise from the host MCU or DC-DC converter. The PACK+/PACK- Kelvin-sense traces must reach the actual pad of the sense resistor, not share copper with the high-current path, to avoid IR-drop induced false SCD trips.
A common pitfall is forgetting to populate the cell-balancing current-limit resistor: omitting it routes the full pack voltage across the internal balance FET, causing thermal failure. Another pitfall is wiring the HIBERNATE pin to a logic-high default that prevents the IC from ever entering the 2 µA Iq mode, which shortens stored-pack shelf life. Finally, do not exceed the absolute maximum VC5-to-VC0 differential listed in the datasheet [DATA_NEEDED: exact value]; for 5S Li-Ion at full charge this is approximately 21 V plus tolerance margin.
Compliance Information
Industrial-grade (-40°C to +85°C). Not AEC-Q100 qualified - not intended for automotive powertrain applications.
