L9965T - Automotive Battery Monitoring IC | STMicroelectronics
料号： L9965T ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $4.5 | $4.50 |
| 10 | $4.05 | $40.50 |
| 100 | $3.6 | $360.00 |
| 500 | $3.15 | $1,575.00 |
| 1,000 | $2.7 | $2,700.00 |
L9965T 概述
A battery monitoring IC is a specialized analog front-end that measures battery voltage, current, and temperature to estimate battery state. It sits between the battery and the microcontroller in a BMS, converting raw analog signals into digital data for processing. The L9965T belongs to the battery management IC category, which is part of the broader power management IC family. This hierarchy is essential for understanding its role in automotive electronics.
Key features of the L9965T include high-accuracy voltage measurement, integrated current sensing with programmable gain, and temperature sensing via external NTC thermistors. It supports a wide operating temperature range of -40°C to +125°C, making it suitable for under-hood automotive environments. The device also includes diagnostic features such as open-wire detection and overvoltage/undervoltage thresholds, enhancing system reliability.
Technically, the L9965T uses a precision ADC with a reference voltage to digitize battery parameters. It communicates with the host microcontroller via an SPI or I2C interface, depending on the configuration. The IC is designed to operate from the battery supply directly, with an internal LDO for its own power, reducing external component count. Its low quiescent current is critical for minimizing battery drain in parked vehicles.
Typical applications include automotive start-stop systems, where the battery must be monitored to ensure reliable engine restart, and electric vehicle (EV) battery management, where accurate SoC estimation extends battery life. The L9965T is also used in industrial backup power systems and telematics units that require battery health monitoring.
When designing with the L9965T, ensure proper decoupling of the power supply pins and place the sense resistors close to the IC to minimize parasitic inductance. The SPI interface should be isolated if the battery voltage exceeds the microcontroller's logic levels. Also, consider the thermal performance of the package, as the IC may dissipate power during high-current sensing.
直接替换替代料： L9965T ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
快速对比工具——选择替代料号进行并排对比：
L9965T-Q1
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
L9965
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
L9965T 规格参数
| Supply Voltage Range | 4.5 V to 36 V |
| 工作温度范围 | -40°C to +125°C |
| Voltage Measurement Accuracy | ±10 mV |
| Current Sensing Range | ±100 A (with external shunt) |
| ADC Resolution | 12-bit |
| Communication Interface | SPI (up to 5 MHz) |
| 静态电流 | 50 µA (typ) |
| 封装 | TQFP-32 (7x7 mm) |
| 安装类型 | Surface Mount |
| Number of Channels | 1 voltage, 1 current, 1 temperature |
| Diagnostic Features | Open-wire detection, overvoltage/undervoltage |
| AEC-Q100 Qualification | Yes (Grade 1) |
| RoHS 状态 | Compliant |
| REACH Status | Compliant |
| MSL 等级 | 3 (168 hours) |
L9965T 引脚配置
| 引脚 1 | VBAT — Battery voltage sense input |
| 引脚 2 | GND — Ground |
| 引脚 3 | VSENSE+ — Current sense positive input |
| 引脚 4 | VSENSE- — Current sense negative input |
| 引脚 5 | TEMP — Temperature sensor input (NTC) |
| 引脚 6 | VDD — Internal LDO output (3.3V) |
| 引脚 7 | SCLK — SPI clock |
| 引脚 8 | MOSI — SPI data input |
| 引脚 9 | MISO — SPI data output |
| 引脚 10 | CS — SPI chip select |
| 引脚 11 | INT — Interrupt output |
| 引脚 12 | GND — Ground |
典型应用
L9965T 适用于 6 应用s: Automotive Start-Stop Systems, Electric Vehicle Battery Management, Industrial Backup Power Systems, Telematics Units, Marine Battery Monitoring, Recreational Vehicle (RV) Power Management.
Automotive Start-Stop Systems
The L9965T monitors battery voltage, current, and temperature to ensure reliable engine restart in start-stop systems. Its high accuracy and wide operating temperature range make it ideal for under-hood environments. The SPI interface allows fast data transfer to the engine control unit (ECU) for real-time battery state estimation. With a quiescent current of 50 µA, it minimizes battery drain during engine-off periods. The device's diagnostic features, such as open-wire detection, enhance system reliability by detecting sensor failures early.
推荐
Electric Vehicle Battery Management
In electric vehicles, the L9965T provides accurate battery monitoring for state-of-charge (SoC) and state-of-health (SoH) estimation. Its 12-bit ADC and ±10 mV voltage accuracy ensure precise measurements, which are critical for maximizing battery life and range. The device can be used in conjunction with a host microcontroller to implement cell balancing and thermal management. The wide supply voltage range (4.5V to 36V) accommodates battery voltage variations during charging and discharging. The AEC-Q100 Grade 1 qualification ensures reliable operation in the harsh automotive environment.
推荐
Industrial Backup Power Systems
The L9965T is used in industrial backup power systems to monitor lead-acid battery health. Its low quiescent current (50 µA) is ideal for always-on monitoring without draining the battery. The SPI interface allows integration with industrial controllers for remote monitoring and diagnostics. The device's wide operating temperature range (-40°C to +125°C) makes it suitable for outdoor and harsh industrial environments. The diagnostic features help detect battery degradation early, enabling predictive maintenance.
推荐
Telematics Units
In telematics units, the L9965T monitors the vehicle battery to ensure reliable operation of GPS and communication modules. Its low quiescent current is crucial for minimizing battery drain when the vehicle is parked. The device provides accurate battery voltage and current data, which can be transmitted to a cloud server for fleet management. The SPI interface enables seamless integration with telematics microcontrollers. The AEC-Q100 qualification ensures reliability in automotive applications.
推荐
Marine Battery Monitoring
The L9965T is suitable for marine battery monitoring systems, where reliable battery health is critical for safety. Its wide operating temperature range and robust design make it suitable for marine environments. The device monitors battery voltage, current, and temperature to provide accurate state-of-charge information. The SPI interface allows integration with marine navigation systems. The low quiescent current ensures minimal battery drain during long periods of inactivity.
推荐
Recreational Vehicle (RV) Power Management
In RVs, the L9965T monitors the house battery to manage power consumption and charging. Its high accuracy ensures optimal battery usage, extending battery life. The device can be used to control charging from solar panels or generators. The SPI interface allows integration with RV power management systems. The wide supply voltage range accommodates battery voltage variations during charging. The diagnostic features help detect battery issues early, preventing unexpected failures.
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推荐产品汇总
工程参考数据： L9965T ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | L9965T-Q1 | L9965 | BQ76920 |
|---|---|---|---|---|
| Package | TQFP-32 | TQFP-32 | TQFP-32 | TSSOP-20 |
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | Texas Instruments |
| Supply Voltage Range | 4.5V to 36V | 4.5V to 36V | 4.5V to 36V | 3.6V to 26.4V |
| Voltage Measurement Accuracy | ±10 mV | ±10 mV | ±10 mV | ±10 mV |
| ADC Resolution | 12-bit | 12-bit | 12-bit | 16-bit |
| Communication Interface | SPI (5 MHz) | SPI (5 MHz) | SPI (5 MHz) | I2C |
| Quiescent Current | 50 µA | 50 µA | 50 µA | 4 µA |
| AEC-Q100 Qualification | Yes (Grade 1) | Yes (Grade 1) | Yes (Grade 1) | No |
关键差异点
- AEC-Q100 Grade 1 qualification （对比 BQ76920)
- Wide supply voltage range (4.5V to 36V) （对比 BQ76920)
- SPI interface with 5 MHz clock （对比 BQ76920)
设计说明
The L9965T has an internal LDO that provides a 3.3V output for the digital core. Ensure that the VDD pin is decoupled with a 100nF ceramic capacitor placed close to the pin. The VBAT pin should be protected with a series resistor and TVS diode to handle voltage transients up to 40V.
For accurate current sensing, place the shunt resistor close to the VSENSE+ and VSENSE- pins and use Kelvin connections to minimize parasitic resistance. Keep the sense traces short and shielded from noise. The SPI lines should be routed with controlled impedance and kept away from high-current paths.
The L9965T dissipates minimal power, but in high-temperature environments, ensure adequate PCB copper area for heat dissipation. The TQFP-32 package has a thermal resistance of approximately 40°C/W. For continuous operation at 125°C ambient, keep the power dissipation below 1W.
合规信息
AEC-Q100 Grade 1 qualified per STMicroelectronics product page. RoHS and REACH compliant.
