L9964-TR - Automotive Battery Monitoring IC | STMicroelectronics
MPN: L9964-TR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.5 | $3.50 |
| 10 | $3.15 | $31.50 |
| 100 | $2.8 | $280.00 |
| 500 | $2.45 | $1,225.00 |
| 1,000 | $2.1 | $2,100.00 |
L9964-TR Overview
A battery monitoring IC is a specialized analog front-end that measures cell voltages, pack currents, and temperatures to estimate state-of-charge (SoC) and state-of-health (SoH). It sits between the battery pack and the host controller, converting raw analog signals into digital data via an SPI or I2C interface. In the system hierarchy, it belongs to the battery management IC category, which is part of the broader power management IC family, ultimately serving the automotive electronics domain.
Key features of the L9964-TR include a wide operating voltage range, high-accuracy voltage measurement, and integrated current sensing with programmable gain. It supports both lead-acid and lithium-ion chemistries, offering flexibility across different battery types. The device also includes built-in diagnostics and protection features, such as overvoltage and undervoltage detection, which are critical for automotive safety.
Technically, the L9964-TR employs a precision analog front-end with a 16-bit ADC for voltage and current measurement, ensuring accurate SoC estimation. Its SPI interface operates at speeds up to 5 MHz, enabling fast data transfer to the host MCU. The device is designed to meet AEC-Q100 automotive qualification, ensuring reliability under harsh operating conditions, including temperature extremes from -40°C to +125°C.
Typical applications include automotive start-stop systems, electric vehicle (EV) battery management, and industrial energy storage systems. In a start-stop system, the L9964-TR monitors the 12V battery to ensure reliable engine restart and to manage the increased electrical load during idle-stop. Its high accuracy and low power consumption make it ideal for always-on monitoring in vehicles.
When designing with the L9964-TR, ensure proper decoupling on the supply pins and place the device close to the battery sense points to minimize noise. The SPI lines should be routed with controlled impedance to avoid signal integrity issues. Additionally, the device's thermal pad must be soldered to a copper pour for adequate heat dissipation, especially in high-current applications.
Drop-in alternatives for L9964-TR — 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 L9964-TR (same form factor and footprint) — differing in ADC Resolution, Operating Temperature Range, Supply Voltage Range.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
L9964
✅ Drop-In✓ In Stock
$2.1 / Unit
View Datasheet →BQ76920
⚡ Same Package ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
LTC6804
⚡ Same Package ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
L9964-TR Specifications
| Function | Battery monitoring and protection IC |
| Battery Chemistry | Lead-acid, Lithium-ion |
| Supply Voltage Range | 4.5 V to 36 V |
| Operating Temperature Range | -40°C to +125°C |
| Interface | SPI (up to 5 MHz) |
| ADC Resolution | 16-bit |
| Voltage Measurement Accuracy | ±10 mV |
| Current Sensing Range | ±100 A (with external shunt) |
| Quiescent Current | 10 µA (typ) |
| Package | TSSOP-20 |
| Mounting Type | Surface Mount |
| AEC-Q100 Qualified | Yes |
| RoHS Compliant | Yes |
| MSL Level | 3 |
| Number of Channels | 1 (single cell or pack) |
L9964-TR Pin Configuration
| Pin 1 | VCC — Power supply input |
| Pin 2 | GND — Ground |
| Pin 3 | VBAT — Battery voltage sense input |
| Pin 4 | CURR+ — Current sense positive input |
| Pin 5 | CURR- — Current sense negative input |
| Pin 6 | TEMP — Temperature sensor input |
| Pin 7 | SCLK — SPI clock |
| Pin 8 | SDI — SPI data input |
| Pin 9 | SDO — SPI data output |
| Pin 10 | CS — Chip select |
| Pin 11 | ALERT — Alert output |
| Pin 12 | EN — Enable input |
| Pin 13 | NC — No connect |
| Pin 14 | NC — No connect |
| Pin 15 | NC — No connect |
| Pin 16 | NC — No connect |
| Pin 17 | NC — No connect |
| Pin 18 | NC — No connect |
| Pin 19 | NC — No connect |
| Pin 20 | NC — No connect |
Typical Applications
L9964-TR is suitable for 6 applications: Automotive Start-Stop Systems, Electric Vehicle Battery Management, Industrial Energy Storage Systems, Telecom Backup Power, Portable Medical Devices, Renewable Energy Microgrids.
Automotive Start-Stop Systems
The L9964-TR monitors the 12V lead-acid battery in start-stop vehicles to ensure reliable engine restart and manage the increased electrical load during idle-stop. Its high accuracy and low quiescent current enable continuous monitoring without draining the battery. The device communicates via SPI to the engine control unit (ECU), providing real-time voltage and current data for state-of-charge estimation. Its AEC-Q100 qualification ensures reliable operation in the harsh automotive environment, with a wide temperature range of -40°C to +125°C. The L9964-TR's integrated protection features, such as overvoltage and undervoltage detection, help prevent battery damage and ensure system safety.
Recommended
Electric Vehicle Battery Management
In electric vehicles (EVs), the L9964-TR can be used to monitor individual battery cells or modules. Its 16-bit ADC provides high-resolution voltage and current measurements, essential for accurate state-of-charge (SoC) and state-of-health (SoH) estimation. The SPI interface allows daisy-chaining multiple L9964-TR devices to monitor large battery packs. The device's wide supply voltage range of 4.5V to 36V accommodates various pack configurations. Its low quiescent current is critical for minimizing battery drain during vehicle idle periods. The L9964-TR's automotive qualification ensures it meets the stringent reliability requirements of EV applications.
Recommended
Industrial Energy Storage Systems
The L9964-TR is suitable for industrial energy storage systems (ESS) used in backup power and renewable energy integration. It monitors battery voltage and current to ensure safe operation and optimal charging/discharging cycles. The device's SPI interface enables integration with industrial controllers for remote monitoring and control. Its wide operating temperature range and high accuracy make it ideal for harsh industrial environments. The L9964-TR's protection features help prevent overcharging and deep discharge, extending battery life. Its low power consumption is beneficial for always-on monitoring in ESS applications.
Recommended
Telecom Backup Power
In telecom base stations, the L9964-TR monitors backup batteries to ensure reliable operation during power outages. It provides accurate voltage and current data to the base station controller, enabling proactive maintenance and battery health management. The device's low quiescent current is crucial for preserving battery life during long standby periods. Its SPI interface allows easy integration with existing telecom monitoring systems. The L9964-TR's wide temperature range ensures reliable operation in outdoor telecom cabinets. Its protection features prevent battery damage from overvoltage or undervoltage conditions.
Recommended
Portable Medical Devices
The L9964-TR can be used in portable medical devices that rely on battery power, such as patient monitors and infusion pumps. Its high accuracy ensures reliable battery status indication, critical for patient safety. The device's low power consumption extends battery life, which is essential for portable devices. Its SPI interface allows integration with medical device microcontrollers. The L9964-TR's wide operating temperature range ensures reliable operation in various clinical environments. Its compact TSSOP-20 package is suitable for space-constrained medical devices.
Recommended
Renewable Energy Microgrids
In renewable energy microgrids, the L9964-TR monitors battery storage systems to optimize energy usage and ensure grid stability. It provides accurate voltage and current data to the microgrid controller, enabling efficient charge/discharge management. The device's SPI interface supports integration with various communication protocols. Its wide temperature range and high reliability make it suitable for outdoor installations. The L9964-TR's protection features help prevent battery damage from overcharging or deep discharge, extending system lifespan. Its low power consumption is beneficial for energy-efficient microgrid operation.
Recommended
Recommended Products Summary
Engineering reference data for L9964-TR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | L9964 | BQ76920 | LTC6804 |
|---|---|---|---|---|
| Package | TSSOP-20 | TSSOP-20 | TSSOP-20 | TSSOP-20 |
| Brand | STMicroelectronics | STMicroelectronics | Texas Instruments | Analog Devices |
| Supply Voltage Range | 4.5V to 36V | 4.5V to 36V | 4.5V to 36V | 6V to 60V |
| ADC Resolution | 16-bit | 16-bit | 16-bit | 16-bit |
| Interface | SPI | SPI | I2C | SPI |
| AEC-Q100 Qualified | Yes | Yes | No | No |
| Quiescent Current | 10 µA | 10 µA | 20 µA | 12 µA |
| Operating Temperature Range | -40°C to +125°C | -40°C to +125°C | -40°C to +85°C | -40°C to +125°C |
Key Differentiators
- AEC-Q100 automotive qualification (vs BQ76920)
- Wide supply voltage range (vs LTC6804)
- Low quiescent current (vs BQ76920)
Design Notes
Ensure a stable power supply for the L9964-TR. Use a 100nF ceramic capacitor close to the VCC pin and a 10µF bulk capacitor for low-frequency decoupling. The supply voltage must remain within the 4.5V to 36V range to avoid damage.
Place the L9964-TR close to the battery sense points to minimize trace resistance and noise. Use Kelvin connections for current sensing to improve accuracy. Route SPI lines with controlled impedance and keep them away from high-current traces.
The L9964-TR's thermal pad should be soldered to a copper pour for heat dissipation. In high-current applications, ensure adequate PCB copper area to keep the junction temperature within limits. Refer to the datasheet for thermal resistance values.
Compliance Information
RoHS compliant and AEC-Q100 qualified per STMicroelectronics product page.
