Battery monitor and protector ICs (analogue front ends) · Series cell count and chemistry, cell-voltage and current accuracy, stand-alone versus host-controlled and daisy-chained architectures, protection thresholds and FET drive, cell balancing, temperature inputs, power modes, interfaces, voltage tolerance and package
A battery monitoring IC — also called a battery analogue front end — measures every cell voltage, pack current and temperature in a lithium battery pack, protects the pack by switching FETs off on faults, and balances the cells, reporting to a host controller. Settle three things before choosing one: the series cell count, chemistry and pack voltage, the measurement accuracy, protections and balancing the pack needs, and the power budget, interfaces and package for the board.
Battery monitor, protector and analogue front-end ICs for multi-cell lithium-ion, lithium-polymer and LiFePO4 packs in industrial, mobility and backup applications. Complete battery management systems and protection boards, fuel-gauge-only ICs, chargers, battery cells and packs are outside this page; battery management systems and battery packs have their own pages.
01
TI's BQ76952 datasheet describes a battery monitor and protector for 3-series to 16-series Li-ion, Li-polymer and LiFePO4 packs, with two independent ADCs for simultaneous current and voltage sampling, cell-voltage measurement accuracy under 10 mV (typical), a coulomb counter with input offset under 1 µV (typical), a ±200 mV measurement range across the sense resistor, a differential cell-input range of −0.2 to 5.5 V, and temperature sensing from an internal sensor and up to nine external thermistors. [1]
It tolerates 85 V on cell-connect and selected pins, accepts cells attached in random order on the production line, and lists applications in battery backup units, e-bikes and LEVs, cordless and garden tools, drones and other industrial packs of 10 series and above. [1]
Accuracy figures differ in how they are stated. Renesas' ISL94202 gives an absolute cell measurement error of ±15 mV for 2.4–4.2 V cells from 0 to 60 °C and ±30 mV for 0.1–4.7 V cells from −40 to 85 °C, and a pack-voltage (VBATT) error of ±200 mV from 0 to 60 °C. Infineon's TLE9012DQU, which uses a dedicated 16-bit delta-sigma ADC for each cell, quotes ±0.2 mV typical initial accuracy at ambient temperature and an end-of-life error of ±1.1 mV for 2.5–3.6 V cells at 25 °C. [2] [3]
Editorial calculation: with a 1 mΩ shunt, the ±200 mV range covers ±200 A; with 0.5 mΩ, ±400 A. Sixteen cells at the ISL94202's default 4.25 V overvoltage threshold total 16 × 4.25 = 68 V, within the BQ76952's 85 V tolerance. [1] [2]
Editorial note: compare like with like — a typical figure (BQ76952, TLE9012DQU initial) is not a guaranteed maximum (ISL94202 limits, TLE9012DQU end-of-life), and temperature range and cell-voltage window change the number. [1] [2] [3]
Give the supplier the chemistry and series cell count, maximum pack voltage and current, shunt value, required cell-voltage and current accuracy, protections and thresholds, FET arrangement (high- or low-side), balancing current, number of temperature inputs, power-mode currents, host interface, operating temperature, package and quantity.
02
The BQ76952 provides voltage, temperature, current and internal-diagnostic protections, an integrated charge pump for high-side NFET protection with optional autonomous recovery, secondary chemical-fuse drive, and autonomous or host-controlled cell balancing at up to 100 mA through a single cell. It lists typical currents of 286 µA in NORMAL mode, 24–41 µA in SLEEP, 9–10 µA in DEEPSLEEP and 1 µA in SHUTDOWN. [1]
Host communication uses 400 kHz I²C, SPI or HDQ one-wire; two programmable LDOs (1.8, 2.5, 3.0, 3.3 or 5.0 V) supply external circuits; customers can program one-time-programmable memory on the production line; it operates from −40 to 85 °C with ±1,000 V HBM and ±250 V CDM ESD ratings, in a 7 × 7 mm 48-pin TQFP. [1]
The ISL94202 shows how protection thresholds are set: discharge overcurrent is selectable from 4 to 96 mV across the sense resistor (default 32 mV) with a 160 ms default detection time, short-circuit from 16 to 256 mV (default 96 mV) with a 200 µs default, and charge overcurrent from 1 to 24 mV (default 8 mV). Voltage protection levels are each programmable to 4.8 V as 12-bit values. Its integrated charge pump drives high-side N-channel FETs, and it works in both parallel and series charge/discharge FET configurations. [2]
Balancing current and method differ: the BQ76952 balances through internal switches at up to 100 mA, the TLE9012DQU's integrated switch allows up to 200 mA per cell with all cells in parallel and PWM balancing, and the ISL94202 drives external balancing FETs from an internal state machine or an external MCU. [1] [3] [2]
Editorial note: balancing current, cell capacity and imbalance set how long balancing takes, so check the maximum balancing current against your cells and the heat it generates on the board. [1]
Editorial calculation: with a 1 mΩ shunt, the ISL94202's default 32 mV discharge-overcurrent setting trips at 32 A and its default 96 mV short-circuit setting at 96 A. To remove 0.5 Ah of imbalance from one cell, 100 mA balancing takes 5 hours and 200 mA takes 2.5 hours. [2] [1] [3]
A dedicated protector IC shows what a part with no ADC or host link offers. ABLIC's S-8225B monitors 3 to 5 series Li-ion cells, selected with its SEL1 and SEL2 pins. Overcharge detection is set between 3.5 and 4.4 V in 50 mV steps with ±20 mV accuracy at 25 °C and ±30 mV from 0 to 60 °C; overdischarge detection is set between 2.2 and 3.2 V in 100 mV steps with ±80 mV accuracy. Delay times are set by external capacitors, the CO and DO outputs are limited to 12 V, it operates from 4 to 26 V (28 V absolute maximum) over −40 to 85 °C, and it draws 20 µA maximum in operation and 3.0 µA maximum in power-down at 25 °C. It comes in a 16-pin TSSOP. [4]
Editorial calculation: a 4.20 V overcharge setting on the S-8225B can trip anywhere from 4.18 to 4.22 V at 25 °C and from 4.17 to 4.23 V across 0–60 °C; on a 5-series pack the 30 mV band amounts to up to 150 mV of total pack voltage if every cell sits at the same edge. [4]
03
Renesas' ISL94202 is a battery pack monitor for 3 to 8 series cells that runs stand-alone with no MCU needed: it automatically shuts down and recovers from out-of-bounds conditions and controls balancing, keeps configuration and calibration in EEPROM, and offers an optional I²C link to an external MCU. It operates from a 4 to 36 V supply over −40 to 85 °C and supports Li-ion CoO2, Mn2O4 and FePO4 chemistries. [2]
Its supply current is 310 µA typical in NORMAL mode (370 µA maximum), 215 µA in IDLE, 210 µA in DOZE, 13 µA typical in SLEEP from 0 to 60 °C and 1 µA in powerdown, all at 33.6 V. It comes in a 48-lead TQFN rated −40 to +85 °C with 1.5 kV HBM and 1 kV CDM ESD ratings. Applications include power tools, battery back-up, light electric vehicles, energy storage and medical equipment. [2]
Infineon's TLE9012DQU is built to be stacked: it measures up to 12 series cells in parallel, communicates through UART or an isolated iso UART daisy chain at 2 Mbit/s with up to 38 devices and CRC protection, and adds five external NTC channels, two internal temperature sensors and four GPIO pins. It runs from 4.75 to 60 V (75 V absolute maximum on VS), draws 4.9 mA typical idle and has sleep leakage of ±1 µA from −40 to 85 °C. It is qualified to AEC-Q100, is an ISO 26262 safety element out of context up to ASIL D, and is designed for HEV, PHEV and BEV packs, 12 V/48 V batteries and energy storage, in a 48-pin PG-TQFP. [3]
Editorial calculation: 38 TLE9012DQU devices × 12 cells gives up to 456 series cells on one daisy chain, against 16 for a single BQ76952 and 8 for a single ISL94202. [3] [1] [2]
| Part | Cells; architecture | Accuracy as stated | Balancing; interface |
|---|---|---|---|
| TI BQ76952 | 3–16 series; host or autonomous protector. [1] | < 10 mV typical. [1] | 100 mA internal; I²C, SPI, HDQ. [1] |
| Renesas ISL94202 | 3–8 series; stand-alone, no MCU needed. [2] | ±15 mV absolute, 2.4–4.2 V, 0–60 °C. [2] | External FETs; I²C (optional). [2] |
| Infineon TLE9012DQU | Up to 12 series; daisy chain of up to 38. [3] | ±0.2 mV typical initial; ±1.1 mV end-of-life. [3] | 200 mA internal; UART, iso UART 2 Mbit/s. [3] |
04
The companies in the manufacturer list below show this product on their own websites. Confirm the legal seller, factory and scope for your order.
Ask each supplier for the datasheet values of cell-voltage and current accuracy over temperature, protection thresholds and delays, balancing current, power-mode currents, interfaces, ESD ratings and package, and for evaluation and configuration tools. [1]
Ask whether the part is qualified for your application: the TLE9012DQU is validated to AEC-Q100 for automotive use, while the ISL94202 and BQ76952 datasheets list industrial and portable applications and a −40 to 85 °C range. [3] [2] [1]
05
This is a functional reference built from the sources cited; it is not one maker's specification.
| Block | What it controls | Fix in the order |
|---|---|---|
| Cell-voltage ADC | Cell readings. [1] | Cells; mV. |
| Coulomb counter ADC | Current; charge. [1] | ±mV; µV offset. |
| Protection subsystem | Fault response. [1] | Thresholds. |
| FET drivers / charge pump | Pack switching. [1] | High-side NFET. |
| Balancing switches | Cell matching. [1] | mA. |
| Interfaces and LDOs | Host link; supplies. [1] | I²C; SPI; HDQ. |
| Configuration memory | Stand-alone settings. [2] | EEPROM; OTP. |
| Isolated daisy-chain port | Stacked devices. [3] | Devices; Mbit/s. |
06
A battery monitoring IC quotation needs values for your pack. The table explains each field, gives published values where a reviewed source states them, and says what to obtain from the supplier.
| Field | What it means and published values | Ask the supplier for |
|---|---|---|
| Number of Cells Monitored | 3–16 (BQ76952); 3–8 (ISL94202); up to 12 per device (TLE9012DQU). [1] [2] [3] | Cells. |
| Cell Voltage Measurement Range | −0.2 to 5.5 V differential. [1] | V. |
| Voltage Measurement Accuracy | < 10 mV typical (BQ76952); ±15 mV absolute, 0–60 °C (ISL94202); ±0.2 mV typical initial (TLE9012DQU). [1] [2] [3] | mV over temp. |
| Temperature Measurement Range | Internal + up to 9 thermistors (BQ76952); 5 NTC + 2 internal (TLE9012DQU). [1] [3] | °C; inputs. |
| Supply Voltage | Up to 85 V tolerance (BQ76952); 4–36 V (ISL94202); 4.75–60 V (TLE9012DQU). [1] [2] [3] | V. |
| Quiescent Current | 286 µA normal, 1 µA shutdown (BQ76952); 310 µA normal, 1 µA powerdown (ISL94202). [1] [2] | µA by mode. |
| Balancing Current | 100 mA (BQ76952); 200 mA (TLE9012DQU); external FETs (ISL94202). [1] [3] [2] | mA; method. |
| Protection Thresholds | Overcurrent 4–96 mV, short-circuit 16–256 mV (ISL94202). [2] | mV; delay. |
| Communication Interface | I²C 400 kHz, SPI, HDQ (BQ76952); I²C (ISL94202); iso UART 2 Mbit/s (TLE9012DQU). [1] [2] [3] | Interface. |
| Operating Temperature Range | −40 to 85 °C. [1] | Range. |
| Package Type | 48-pin TQFP 7 × 7 mm (BQ76952); 48-lead TQFN (ISL94202); PG-TQFP-48 (TLE9012DQU). [1] [2] [3] | Package. |
| ESD Rating | ±1 kV HBM, ±250 V CDM (BQ76952); 1.5 kV HBM, 1 kV CDM (ISL94202). [1] [2] | kV. |
07
Paste it into your enquiry below or into an email to a maker, then replace every bracket.
Chemistry/series: [Li-ion; LFP; S] Pack: [V max; A; shunt mΩ] Accuracy: [mV; current %] Protections: [OV; UV; OC; OT] FETs: [high/low side] Balancing: [mA] Power/interface: [µA; I²C/SPI] Package/quantity: [type; units]
These companies list this product on their own websites.
Its website lists battery protection ICs, including secondary protection and AFE parts.
Product scope checked 2026-10-12
Its website lists multi-cell lithium battery protection ICs.
Product scope checked 2026-10-12
Explore company information and manufacturing capabilities, then discuss the scope of your project with a relevant supplier.
TI's BQ76952 monitors 3 to 16 series cells, Renesas' ISL94202 3 to 8, and Infineon's TLE9012DQU up to 12 per device with up to 38 devices daisy-chained. [1] [2] [3]
The BQ76952 quotes under 10 mV typical; the ISL94202 limits absolute cell error to ±15 mV from 0 to 60 °C; the TLE9012DQU quotes ±0.2 mV typical initial accuracy. [1] [2] [3]
The BQ76952 allows up to 100 mA and the TLE9012DQU up to 200 mA per cell; the ISL94202 drives external balancing FETs. [1] [3] [2]
The BQ76952 lists 24–41 µA in SLEEP, 9–10 µA in DEEPSLEEP and 1 µA in SHUTDOWN. [1]
ABLIC's S-8225B, for 3 to 5 series cells, sets overcharge detection between 3.5 and 4.4 V with ±20 mV accuracy at 25 °C and ±30 mV from 0 to 60 °C, and overdischarge detection with ±80 mV. [4]
Sources checked 2026-10-12. Datasheets from Texas Instruments (BQ76952), Renesas (ISL94202) and Infineon (TLE9012DQU), plus ABLIC's S-8225B protector datasheet page, are used to show what a battery monitoring IC specification covers and how architectures differ; values for your order must come from the supplier's current datasheet.
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