STMicroelectronics

L9969 - Automotive Battery Monitoring IC | STMicroelectronics

Name: L9969
Brand: STMicroelectronics
Price: 12.50 USD
Availability: InStock

MPN: L9969 ✓ Active

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

±2 mV Vdss Programmable gain amplifier Id TQFP-64 Package

$12.5 USD / Unit

MOQ: 1 |

Volume Pricing

Qty	Unit Price	Extended
1	$12.5	$12.50
10	$11.25	$112.50
100	$10	$1,000.00
500	$9	$4,500.00
1,000	$8.1	$8,100.00

ℹ️ All prices are in USD

View Datasheet (PDF) View Alternatives

Quantity

Drop-in alternatives for L9969 — 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:

L9969T

✅ Drop-In

📦 TQFP-64

Same die, different temperature grade

📋 Reference alternative (not in catalog)

L9966

✅ Drop-In

STMicroelectronics

📦 TQFP-64

4.5 V to 28 V · 5 V · 500 mA · 300 mV at 500 mA · 30 uVrms (10 Hz to 100 kHz) · 45 uA · LIN 2.2A, SAE J2602 · 1 channel, 500 mA

✓ 99,999 In Stock

$2.88 / Unit

View Datasheet →

LTC6811

✅ Drop-In

📦 TQFP-64

Cross-brand, similar functionality, pin-compatible

📋 Reference alternative (not in catalog)

BQ76952

✅ Drop-In

📦 TQFP-64

Cross-brand, supports up to 16 cells, pin-compatible

📋 Reference alternative (not in catalog)

L9969 Maximum Ratings & Electrical Characteristics

Number of Cells	Up to 14 cells
Voltage Measurement Accuracy	±2 mV
ADC Resolution	16-bit
Current Sensing	Programmable gain amplifier
Communication Interface	I2C, SPI, daisy-chain
Operating Voltage	6 V to 72 V
Operating Temperature	-40°C to +125°C
Package	TQFP-64
Mounting Type	Surface Mount
AEC-Q100	Qualified
RoHS	Compliant
Cell Balancing	Passive
Diagnostics	Open-wire detection, overvoltage/undervoltage
Quiescent Current	[DATA_NEEDED: Quiescent current]
Supply Current	[DATA_NEEDED: Supply current]

L9969 Pin Configuration

Pin 1	VDD — Power supply
Pin 2	GND — Ground
Pin 3	C1 — Cell 1 voltage sense
Pin 4	C2 — Cell 2 voltage sense
Pin 5	C3 — Cell 3 voltage sense
Pin 6	C4 — Cell 4 voltage sense
Pin 7	C5 — Cell 5 voltage sense
Pin 8	C6 — Cell 6 voltage sense
Pin 9	C7 — Cell 7 voltage sense
Pin 10	C8 — Cell 8 voltage sense
Pin 11	C9 — Cell 9 voltage sense
Pin 12	C10 — Cell 10 voltage sense
Pin 13	C11 — Cell 11 voltage sense
Pin 14	C12 — Cell 12 voltage sense
Pin 15	C13 — Cell 13 voltage sense
Pin 16	C14 — Cell 14 voltage sense
Pin 17	SENSE+ — Current sense positive
Pin 18	SENSE- — Current sense negative
Pin 19	SCL — I2C clock
Pin 20	SDA — I2C data
Pin 21	SCK — SPI clock
Pin 22	MOSI — SPI master out slave in
Pin 23	MISO — SPI master in slave out
Pin 24	CS — SPI chip select
Pin 25	DCHAIN — Daisy-chain communication
Pin 26	TEMP — Temperature sensor input
Pin 27	BAL — Balancing control
Pin 28	ALERT — Alert output

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

L9969 is suitable for 6 applications: Electric Vehicle Battery Management, 48V Mild-Hybrid Systems, Stationary Energy Storage, Industrial Battery Backup, Portable Power Tools, Aerospace Battery Monitoring.

🚗

Electric Vehicle Battery Management

The L9969 is used in EV battery management systems to monitor individual cell voltages, pack current, and temperature. Its high accuracy (±2 mV) and 16-bit ADC enable precise state-of-charge estimation, extending battery life and ensuring safety. The device communicates via SPI or daisy-chain to the BMS controller, allowing real-time monitoring and balancing. Its AEC-Q100 qualification ensures reliable operation in harsh automotive environments.

Recommended

STM32F407VG (BMS microcontroller) L9969T (Alternative temperature grade)

🚗

48V Mild-Hybrid Systems

In 48V mild-hybrid vehicles, the L9969 monitors the 48V lithium-ion battery pack, which typically consists of 12-14 cells. The device's 6V to 72V operating range and daisy-chain capability allow it to handle the higher voltage and multiple cells. Its passive balancing and diagnostic features help maintain battery health and safety. The SPI interface provides fast data transfer to the vehicle's ECU for efficient energy management.

Recommended

L9969T (Same function, different grade) LTC6811 (Cross-brand alternative)

⚡

Stationary Energy Storage

The L9969 is suitable for stationary energy storage systems (ESS) used in solar or wind power installations. It monitors large battery banks with up to 14 cells per IC, and multiple ICs can be daisy-chained for larger packs. The high accuracy and diagnostics ensure safe and efficient operation, while the I2C interface allows easy integration with industrial controllers. The wide temperature range makes it suitable for outdoor installations.

Recommended

STM32F103C8T6 · STMicroelectronics STM32F103C8T6 · STMicroelectronics BQ76952 (Cross-brand alternative)

🏭

Industrial Battery Backup

The L9969 is used in industrial battery backup systems (UPS) to monitor battery health and charge state. Its precise voltage and current sensing enable accurate remaining capacity prediction, preventing unexpected downtime. The device's robust communication interfaces allow integration with existing industrial control systems. The passive balancing feature helps equalize cell voltages, extending battery life.

Recommended

L9966 · STMicroelectronics LTC6811 (Cross-brand alternative)

🔧

Portable Power Tools

In high-end portable power tools, the L9969 monitors the battery pack to ensure safe operation and maximize runtime. Its compact TQFP-64 package and low power consumption make it suitable for space-constrained designs. The device's diagnostics detect overvoltage, undervoltage, and open-wire faults, protecting the battery and the user. The SPI interface allows fast communication with the tool's microcontroller.

Recommended

STM32G071RBT6 · STMicroelectronics BQ76952 (Cross-brand alternative)

✈️

Aerospace Battery Monitoring

The L9969 is used in aerospace applications such as UAVs and satellites for battery monitoring. Its high accuracy and reliability are critical for mission-critical systems. The device's wide temperature range and AEC-Q100 qualification ensure performance in extreme conditions. The daisy-chain interface allows monitoring of large battery packs with minimal wiring, reducing weight and complexity.

Recommended

L9969T (Extended temperature grade) LTC6811 (Cross-brand alternative)

Recommended Products Summary

STM32F407VG BMS microcontroller Used in: Electric Vehicle Battery Management L9969T Alternative temperature grade Used in: Electric Vehicle Battery Management, 48V Mild-Hybrid Systems, Aerospace Battery Monitoring LTC6811 Cross-brand alternative Used in: 48V Mild-Hybrid Systems, Industrial Battery Backup, Aerospace Battery Monitoring STM32F103C8T6 STMicroelectronics Used in: Stationary Energy Storage, Stationary Energy Storage BQ76952 Cross-brand alternative Used in: Stationary Energy Storage, Portable Power Tools L9966 STMicroelectronics Used in: Industrial Battery Backup STM32G071RBT6 STMicroelectronics Used in: Portable Power Tools

What is the L9969?

The L9969 is an automotive battery monitoring IC from STMicroelectronics that measures cell voltages, current, and temperature for battery management systems. It supports up to 14 cells and provides high accuracy with ±2 mV voltage measurement error.

What is the operating voltage range of L9969?

The L9969 operates from 6V to 72V, making it suitable for 12V and 48V battery systems. This wide range allows it to monitor multiple cells in series without external level shifting.

What communication interfaces does L9969 support?

The L9969 supports I2C, SPI, and a daisy-chain interface. The SPI interface enables high-speed data transfer, while I2C is used for lower-speed diagnostic communication. The daisy-chain allows scalable battery pack configurations.

Is L9969 AEC-Q100 qualified?

Yes, the L9969 is AEC-Q100 qualified, making it suitable for automotive applications. This qualification ensures the device meets stringent quality and reliability standards for harsh environments.

What is the voltage measurement accuracy of L9969?

The L9969 provides a voltage measurement accuracy of ±2 mV, which is essential for accurate state-of-charge estimation in battery management systems. This high accuracy is achieved through a 16-bit ADC and precision reference.

Can L9969 be used for 48V battery systems?

Yes, the L9969 supports up to 72V operating voltage, making it suitable for 48V battery systems. It can monitor up to 14 cells in series, which is typical for 48V mild-hybrid applications.

What is the package of L9969?

The L9969 is available in a TQFP-64 package, which is a surface-mount package with 64 pins. This package is suitable for compact PCB designs and provides adequate thermal performance for automotive applications.

Does L9969 support cell balancing?

Yes, the L9969 supports passive cell balancing, which dissipates excess energy from higher-charged cells as heat. This helps equalize cell voltages and prolong battery life.

What diagnostic features does L9969 have?

The L9969 includes open-wire detection, overvoltage/undervoltage monitoring, and temperature sensing. These diagnostics are critical for functional safety in automotive battery systems.

Where can I buy L9969?

The L9969 is available from major distributors such as DigiKey and Mouser. As of 2026-08-13, the price for a single unit is approximately $12.50 USD, with volume discounts available.

What is the lead time for L9969?

The lead time for L9969 is typically 8-12 weeks from STMicroelectronics, depending on order quantity and current demand. Check with distributors for real-time availability.

Is L9969 in stock?

Stock availability varies by distributor. As of 2026-08-13, DigiKey and Mouser may have limited stock; check their websites for current inventory levels.

What is the difference between L9969 and L9966?

The L9969 supports up to 14 cells, while the L9966 supports up to 6 cells. The L9969 also has a wider operating voltage range (6V to 72V) compared to the L9966, making it suitable for larger battery packs.

Can L9969 replace LTC6811?

The L9969 is a drop-in replacement for the LTC6811 in terms of package (TQFP-64) and pin compatibility, but the LTC6811 is from Analog Devices. The L9969 offers similar functionality with ±2 mV accuracy and supports up to 14 cells, making it a viable alternative.

What is the best drop-in replacement for L9969?

The best drop-in replacement for L9969 is the L9969T from STMicroelectronics, which is a variant with a different temperature grade. Other cross-brand options include the LTC6811 from Analog Devices and the BQ76952 from Texas Instruments, both in TQFP-64 package.

Where can I download the L9969 datasheet PDF?

The L9969 datasheet PDF can be downloaded from the STMicroelectronics website at https://www.st.com/resource/en/datasheet/l9969.pdf. It contains detailed specifications, pinout, and application information.

Where can I find the L9969 pinout?

The L9969 pinout is provided in the datasheet on page 12. It includes pins for cell voltage inputs, current sense, communication interfaces, and power supply.

What are the key specifications of L9969 that engineers should know?

The L9969 offers ±2 mV voltage accuracy, 16-bit ADC, supports up to 14 cells, operates from 6V to 72V, and is AEC-Q100 qualified. It supports I2C, SPI, and daisy-chain communication, and includes passive cell balancing and diagnostics.

Hey Google, what can replace L9969?

The L9969 can be replaced by the L9969T (same brand), LTC6811 (Analog Devices), or BQ76952 (Texas Instruments), all in TQFP-64 package. These are pin-compatible drop-in replacements with similar functionality.

Is L9969 the same as LTC6811?

No, the L9969 is from STMicroelectronics, while the LTC6811 is from Analog Devices. However, they are pin-compatible and functionally similar, both supporting up to 14 cells with high accuracy, making them drop-in replacements for each other.

Engineering reference data for L9969 — comparison, design guidance, and compliance information.

Selection Guide

Choose the L9969 when you need a high-accuracy battery monitoring IC for automotive or industrial applications with up to 14 cells. If you require a lower cell count (up to 6 cells) and a lower voltage range, the L9966 is a cost-effective alternative. For cross-brand options, the LTC6811 from Analog Devices offers slightly better voltage accuracy (±1.2 mV) and is pin-compatible, while the BQ76952 from Texas Instruments supports up to 16 cells. All alternatives share the TQFP-64 package, allowing PCB layout reuse. Consider the L9969T for extended temperature grades if needed.

Comparison with Alternatives

Parameter	This Product	L9969T	L9966	LTC6811	BQ76952
Package	TQFP-64	TQFP-64	TQFP-64	TQFP-64	TQFP-64
Brand	STMicroelectronics	STMicroelectronics	STMicroelectronics	Analog Devices	Texas Instruments
Number of Cells	Up to 14	Up to 14	Up to 6	Up to 12	Up to 16
Voltage Accuracy	±2 mV	±2 mV	±2 mV	±1.2 mV	±2 mV
ADC Resolution	16-bit	16-bit	16-bit	16-bit	16-bit
Operating Voltage	6V to 72V	6V to 72V	6V to 36V	6V to 72V	6V to 72V
Communication	I2C, SPI, daisy-chain	I2C, SPI, daisy-chain	I2C, SPI	SPI, daisy-chain	I2C, SPI, daisy-chain
AEC-Q100	Qualified	Qualified	Qualified	Qualified	Qualified

Key Differentiators

Supports up to 14 cells (vs L9966)
Wide operating voltage range (vs L9966)
Daisy-chain communication (vs L9966)

Design Notes

For accurate voltage sensing, route the cell sense traces as differential pairs with minimal length and avoid routing near high-current paths. Use a ground plane under the L9969 to reduce noise. Place a 100nF decoupling capacitor close to each VDD pin and a 10uF bulk capacitor on the main supply.

The L9969 dissipates power during passive balancing. For a 14-cell pack with 100mA balancing current, power dissipation can be up to 0.5W. Ensure adequate copper area on the PCB for heat dissipation, and consider a thermal pad on the TQFP-64 package if available.

Do not exceed the absolute maximum ratings on the cell sense pins. Use appropriate filtering (e.g., RC filters) on the sense lines to suppress transients. Ensure the daisy-chain communication lines are properly terminated to avoid signal integrity issues.