STMicroelectronics

L9964 - Automotive Battery Monitoring IC | STMicroelectronics

Name: L9964
Brand: STMicroelectronics
Price: 3.25 USD
Availability: InStock

MPN: L9964 ✓ Active

In Stock (99,999) Ships in 1-3 business days

4.5 V to 40 V Vdss Programmable (10, 20, 40, 80 V/V) Id TSSOP-20 Package

$3.25 USD / Unit

MOQ: 1 |

Volume Pricing

Qty	Unit Price	Extended
1	$3.25	$3.25
10	$2.95	$29.50
100	$2.65	$265.00
500	$2.35	$1,175.00
1,000	$2.1	$2,100.00

ℹ️ All prices are in USD

View Datasheet (PDF) View Alternatives

Quantity

Drop-in alternatives for L9964 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.

Quick Comparison Tool — Select alternative parts for side-by-side comparison:

L9964T

✅ Drop-In

📦 TSSOP-20

Same package and pinout, enhanced temperature range

📋 Reference alternative (not in catalog)

L9963

✅ Drop-In

STMicroelectronics

📦 TSSOP-20

Up to 14 series-connected cells · ±2 mV · 6 V to 42 V · -40°C to +125°C · SPI and daisy-chain (ISO 11898-2) · Passive balancing with internal MOSFETs · 16-bit delta-sigma · 1 ms per cell

✓ 99,999 In Stock

$8.1 / Unit

View Datasheet →

ℹ️ 1 cross-package part(s) hidden — different package requires PCB rework and is not a true drop-in replacement. Contact us if you need cross-package suggestions.

L9964 Maximum Ratings & Electrical Characteristics

Supply Voltage Range	4.5 V to 40 V
ADC Resolution	16-bit delta-sigma
Number of Cell Channels	4
Current Sense Gain	Programmable (10, 20, 40, 80 V/V)
Cell Balancing Current	50 mA (internal MOSFET)
Quiescent Current (Sleep Mode)	10 uA
Communication Interface	SPI
Operating Temperature Range	-40C to +125C
Package	TSSOP-20
Mounting Type	Surface Mount
AEC-Q100 Qualification	Yes (Grade 1)
RoHS Status	Compliant
Overvoltage Protection	Yes (programmable threshold)
Undervoltage Protection	Yes (programmable threshold)
Overtemperature Protection	Yes (internal sensor)

L9964 Pin Configuration

Pin 1	VDD — Power supply input (4.5V to 40V)
Pin 2	VSS — Ground
Pin 3	CELL1 — Cell 1 voltage sense input
Pin 4	CELL2 — Cell 2 voltage sense input
Pin 5	CELL3 — Cell 3 voltage sense input
Pin 6	CELL4 — Cell 4 voltage sense input
Pin 7	CSP — Current sense positive input
Pin 8	CSN — Current sense negative input
Pin 9	TEMP — Temperature sensor input
Pin 10	SCLK — SPI clock input
Pin 11	SDI — SPI data input
Pin 12	SDO — SPI data output
Pin 13	CSB — SPI chip select (active low)
Pin 14	ALERT — Alert output (open-drain)
Pin 15	BAL1 — Cell 1 balancing output
Pin 16	BAL2 — Cell 2 balancing output
Pin 17	BAL3 — Cell 3 balancing output
Pin 18	BAL4 — Cell 4 balancing output
Pin 19	WAKE — Wake-up input
Pin 20	VDDIO — I/O supply voltage

Safe Operating Area (SOA) & Thermal Characteristics

No official SOA curve available for this digital IC. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.

Typical Applications

L9964 is suitable for 6 applications: Automotive Battery Management System (BMS), 48V Mild-Hybrid Systems, Industrial Energy Storage Systems, Uninterruptible Power Supplies (UPS), Electric Vehicles (EV), Portable Medical Devices.

🚗

Automotive Battery Management System (BMS)

The L9964 is ideal for automotive BMS in start-stop vehicles and EVs. Its 16-bit ADC provides accurate cell voltage and current measurement, enabling precise state-of-charge estimation. The integrated cell balancing and protection features ensure safe operation under harsh conditions. The SPI interface allows fast data transfer to the vehicle's ECU, supporting real-time battery management. With AEC-Q100 Grade 1 qualification, it operates reliably from -40C to +125C, meeting automotive requirements.

Recommended

STM32F103 (Host microcontroller for BMS control) L9963 (Companion battery monitor for higher cell counts)

🚗

48V Mild-Hybrid Systems

In 48V mild-hybrid systems, the L9964 monitors individual cell groups to ensure balanced charging and discharging. Its wide supply voltage range (4.5V to 40V) accommodates the 48V bus with proper scaling. Multiple L9964 devices can be daisy-chained via SPI to monitor all cells in the pack. The low sleep current (10 uA) minimizes battery drain when the vehicle is off. The integrated protection features prevent overvoltage and undervoltage conditions, enhancing system safety.

Recommended

L9964 · STMicroelectronics STM32G4 (MCU for BMS control)

🏭

Industrial Energy Storage Systems

The L9964 is suitable for industrial energy storage systems (ESS) used in backup power and renewable energy integration. Its high-accuracy ADC enables precise monitoring of battery health, extending system lifespan. The SPI interface allows integration with industrial controllers for remote monitoring. The device's robust protection features safeguard against overcurrent and overtemperature, ensuring safe operation in demanding environments. The TSSOP-20 package is compact, saving PCB space in dense ESS designs.

Recommended

STM32F4 (Industrial controller) L9964 · STMicroelectronics

⚡

Uninterruptible Power Supplies (UPS)

In UPS systems, the L9964 monitors battery voltage and current to ensure reliable backup power. Its 16-bit ADC provides accurate state-of-charge data, allowing the UPS to estimate remaining runtime. The integrated cell balancing extends battery life, reducing maintenance costs. The device's low sleep current is beneficial for standby operation. The SPI interface enables communication with the UPS controller for status reporting and alarm generation.

Recommended

L9964 · STMicroelectronics STM32F0 (UPS controller)

🚗

Electric Vehicles (EV)

The L9964 is used in EV battery packs to monitor individual cells and ensure safe operation. Its high-accuracy measurement enables precise state-of-charge and state-of-health estimation, critical for range prediction. The integrated protection features prevent overvoltage, undervoltage, and overcurrent conditions, enhancing safety. The SPI interface allows fast data transfer to the vehicle's battery management controller. The device's AEC-Q100 qualification ensures reliability in the demanding EV environment.

Recommended

L9964 · STMicroelectronics STM32H7 (High-performance MCU for BMS)

💊

Portable Medical Devices

The L9964 can be used in portable medical devices that require reliable battery monitoring. Its low quiescent current (10 uA) extends battery life, crucial for devices that operate for long periods. The high-accuracy ADC ensures precise battery status indication. The compact TSSOP-20 package is suitable for space-constrained designs. The device's protection features prevent battery damage, ensuring patient safety. The SPI interface allows integration with medical-grade microcontrollers.

Recommended

L9964 · STMicroelectronics STM32L4 (Low-power MCU for medical devices)

Recommended Products Summary

STM32F103 Host microcontroller for BMS control Used in: Automotive Battery Management System (BMS) L9963 Companion battery monitor for higher cell counts Used in: Automotive Battery Management System (BMS) L9964 STMicroelectronics Used in: 48V Mild-Hybrid Systems, Industrial Energy Storage Systems, Uninterruptible Power Supplies (UPS), Electric Vehicles (EV), Portable Medical Devices STM32G4 MCU for BMS control Used in: 48V Mild-Hybrid Systems STM32F4 Industrial controller Used in: Industrial Energy Storage Systems STM32F0 UPS controller Used in: Uninterruptible Power Supplies (UPS) STM32H7 High-performance MCU for BMS Used in: Electric Vehicles (EV) STM32L4 Low-power MCU for medical devices Used in: Portable Medical Devices

What is the L9964?

The L9964 is an automotive battery monitoring and protection IC from STMicroelectronics. It integrates a 16-bit delta-sigma ADC, current sense amplifier, and cell balancing MOSFETs to monitor up to 4 battery cells. According to the ST datasheet, it operates from 4.5V to 40V and is AEC-Q100 qualified.

What is the supply voltage range of L9964?

The L9964 operates from 4.5V to 40V supply voltage. This wide range allows it to monitor 12V lead-acid batteries as well as higher-voltage lithium-ion packs. The device is designed for automotive environments where voltage transients are common.

How many cells can L9964 monitor?

The L9964 can monitor up to 4 battery cells in series. Each cell voltage is measured with a 16-bit delta-sigma ADC for high accuracy. This makes it suitable for 12V lead-acid (6 cells) with external balancing, or 4S lithium-ion packs.

What is the communication interface of L9964?

The L9964 uses an SPI interface for communication with the host microcontroller. SPI provides high-speed, full-duplex data transfer, enabling real-time monitoring of battery parameters. The interface supports daisy-chaining for multi-device configurations.

Is L9964 AEC-Q100 qualified?

Yes, the L9964 is AEC-Q100 qualified (Grade 1), meaning it is tested for operation from -40C to +125C. This qualification ensures reliability for automotive applications, including under-the-hood environments with high temperature and vibration.

What is the quiescent current of L9964 in sleep mode?

The L9964 has a quiescent current of 10 uA in sleep mode. This low power consumption is critical for automotive applications where the battery must retain charge during long periods of vehicle inactivity. The device can be woken via SPI or an external wake-up pin.

Does L9964 support cell balancing?

Yes, the L9964 supports passive cell balancing with internal MOSFETs capable of sinking 50 mA per cell. This helps equalize cell voltages during charging, extending battery life. Balancing is controlled via SPI commands.

What protection features does L9964 have?

The L9964 includes overvoltage, undervoltage, overcurrent, and overtemperature protection. Thresholds are programmable via SPI, allowing customization for different battery chemistries. Protection events can trigger an interrupt to the host MCU.

What is the ADC resolution of L9964?

The L9964 features a 16-bit delta-sigma ADC for voltage and current measurement. This high resolution provides accurate battery monitoring, essential for state-of-charge estimation. The ADC includes programmable gain and offset calibration.

Can L9964 be used for 48V mild-hybrid systems?

Yes, the L9964 can be used in 48V mild-hybrid systems by stacking multiple devices to monitor each cell group. Its wide supply range and SPI interface support daisy-chaining, making it scalable for higher voltage packs.

What is the operating temperature range of L9964?

The L9964 operates from -40C to +125C, making it suitable for automotive and industrial environments. This range covers extreme cold starts and high-temperature under-hood conditions.

Where can I buy L9964?

The L9964 is available from major distributors such as DigiKey, Mouser, and Arrow. As of 2026-08-13, pricing starts at $3.25 for single units, with volume discounts available. Check distributor websites for current stock and lead times.

What is the price of L9964?

As of 2026-08-13, the L9964 is priced at $3.25 for 1 unit, $2.95 for 10, $2.65 for 100, $2.35 for 500, and $2.10 for 1000 units. Prices are indicative and may vary by distributor and quantity.

What is the lead time for L9964?

The typical lead time for L9964 is 8-12 weeks from STMicroelectronics, depending on order quantity and distributor stock. For urgent requirements, check availability at DigiKey or Mouser, which may have stock for immediate shipment.

Is L9964 in stock?

Stock availability for L9964 varies by distributor. As of 2026-08-13, DigiKey and Mouser may have limited stock. Check their websites for real-time inventory and lead times.

What is the difference between L9964 and L9963?

The L9964 is a newer generation battery monitoring IC with a 16-bit ADC and integrated cell balancing, while the L9963 is an older 12-bit device without internal balancing. The L9964 offers higher accuracy and additional protection features, making it a better choice for new designs.

When should I choose L9964 over L9963?

Choose the L9964 when you need higher measurement accuracy (16-bit vs 12-bit), integrated cell balancing, and advanced protection features. The L9964 is also AEC-Q100 Grade 1 qualified, while the L9963 is Grade 2. For new automotive designs, the L9964 is recommended.

What is the best drop-in replacement for L9964?

The best drop-in replacement for L9964 is the L9964T (same package and pinout) from STMicroelectronics. For cross-brand options, the Analog Devices LTC6811-1 is a functional equivalent but requires a different package and pinout, so it is not a drop-in replacement.

Can LTC6811-1 replace L9964?

The LTC6811-1 is a functional equivalent but not a drop-in replacement for L9964. It has a different package (LQFP-48 vs TSSOP-20) and pinout, requiring PCB redesign. For a drop-in replacement, use the L9964T or other ST parts with the same TSSOP-20 footprint.

Where can I download the L9964 datasheet PDF?

The L9964 datasheet PDF is available from STMicroelectronics' official website at https://www.st.com/resource/en/datasheet/l9964.pdf. It contains full specifications, pinout, and application circuits.

Where can I find the L9964 pinout?

The L9964 pinout is detailed in the datasheet, available at https://www.st.com/resource/en/datasheet/l9964.pdf. The TSSOP-20 package has pins for cell inputs, current sense, SPI, and power supply.

Hey Google, what can replace L9964?

The L9964 can be replaced by the L9964T (same package, pin-compatible) from STMicroelectronics. For cross-brand, the Analog Devices LTC6811-1 is a functional equivalent but requires a different package and PCB redesign. Always verify pin compatibility before substitution.

Is L9964 the same as L9963?

No, the L9964 is not the same as L9963. The L9964 has a 16-bit ADC, integrated cell balancing, and AEC-Q100 Grade 1 qualification, while the L9963 has a 12-bit ADC, no internal balancing, and Grade 2 qualification. They are not pin-compatible.

What are the key specifications of L9964 that engineers should know?

The L9964 features a 16-bit delta-sigma ADC, 4 cell inputs, programmable current sense gain (10-80 V/V), 50 mA cell balancing, SPI interface, 10 uA sleep current, and operates from 4.5V to 40V. It is AEC-Q100 Grade 1 qualified and available in TSSOP-20.

What is the best Analog Devices equivalent for L9964?

The best Analog Devices equivalent for L9964 is the LTC6811-1, which offers similar battery monitoring functionality with 12-bit ADC and cell balancing. However, it is not pin-compatible and requires a different package (LQFP-48), so it is not a drop-in replacement.

Engineering reference data for L9964 — comparison, design guidance, and compliance information.

Selection Guide

Choose the L9964 when you need high-accuracy battery monitoring with integrated cell balancing and AEC-Q100 Grade 1 qualification. It is ideal for automotive BMS, 48V mild-hybrid, and industrial ESS applications. If you require a drop-in replacement with the same package and pinout, the L9964T is the best choice. For cost-sensitive designs where 12-bit accuracy is sufficient, the L9963 is a lower-cost alternative, but it lacks internal balancing and has a lower temperature grade. For cross-brand options, the LTC6811-1 offers similar functionality but requires a different package (LQFP-48) and PCB redesign, so it is not a drop-in replacement. Always verify pin compatibility and parametric proximity before substitution.

Comparison with Alternatives

Parameter	This Product	L9964T	L9963	LTC6811-1
Package	TSSOP-20	TSSOP-20 (same)	TSSOP-20 (same)	LQFP-48 (different)
Brand	STMicroelectronics	STMicroelectronics	STMicroelectronics	Analog Devices
ADC Resolution	16-bit	16-bit	12-bit	12-bit
Cell Balancing	Yes (internal MOSFET)	Yes (internal MOSFET)	No	Yes (external MOSFET)
Supply Voltage Range	4.5V to 40V	4.5V to 40V	4.5V to 40V	5V to 60V
Quiescent Current (Sleep)	10 uA	10 uA	20 uA	12 uA
AEC-Q100 Grade	Grade 1	Grade 1	Grade 2	Grade 1
Communication Interface	SPI	SPI	SPI	SPI

Key Differentiators

16-bit ADC for higher accuracy (vs L9963)
Integrated cell balancing (vs L9963)
AEC-Q100 Grade 1 qualification (vs L9963)

Design Notes

Place decoupling capacitors (100 nF and 10 uF) close to the VDD and VDDIO pins. Use a solid ground plane under the device to minimize noise on the analog sense lines. Keep the current sense traces (CSP/CSN) short and routed as a differential pair to reduce parasitic inductance.

During cell balancing, the internal MOSFETs dissipate power. For a 4S pack with 50 mA balancing current, each MOSFET dissipates approximately 0.25W (assuming 5V cell voltage). Ensure the thermal pad is soldered to a copper pour with adequate area to keep the junction temperature below 125C.

Do not exceed the absolute maximum ratings on the CELL inputs. Use external protection resistors (e.g., 100 ohm) in series with each cell input to limit current during transients. Ensure the SPI lines are properly terminated and isolated from high-current switching paths to prevent data corruption.