L9988 - 12V Li-Ion Battery Management System Solution | STMicroelectronics
MPN: L9988 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.5 | $8.50 |
| 10 | $7.8 | $78.00 |
| 100 | $6.9 | $690.00 |
| 500 | $6.2 | $3,100.00 |
| 1,000 | $5.6 | $5,600.00 |
L9988 Overview
A battery management system (BMS) is an electronic system that manages a rechargeable battery pack, monitoring its state, calculating secondary data, reporting that data, protecting the battery from operating outside its safe operating area, and controlling its environment. The L9988 is a dedicated BMS IC that integrates cell monitoring, balancing, and protection functions, targeting up to ASIL-D safety levels in demanding systems. It sits within the hierarchy of power management ICs, specifically in the battery management subsystem, and is essential for ensuring the safety, reliability, and longevity of Li-Ion battery packs.
Key features of the L9988 include dedicated high-precision ADCs that synchronously acquire cell and pack voltages, ensuring accurate and simultaneous measurement. It integrates timed and PWM-based odd-even passive balancing for each cell, which helps equalize cell voltages and extend pack life. The device also includes 4 analog inputs for external NTC thermistor connection and 2 general-purpose I/Os, providing flexibility for temperature monitoring and system control. The L9988 can be powered directly from the battery stack, and its programmable voltage regulators can supply all system components, including the MCU, CAN transceiver, and NTCs.
The L9988 also integrates a dual predriver for driving two independent groups of circuit breaker (CB) back-to-back MOSFETs, enabling safe connection and disconnection of the battery pack. This feature is critical for protecting the pack from overcurrent, overvoltage, and other fault conditions. The device is designed to achieve up to ASIL-D targets, making it suitable for automotive safety-critical applications.
Typical applications include automotive 12V Li-Ion battery packs for start-stop systems, mild hybrid vehicles, and industrial battery backup systems. The L9988's high accuracy and integrated protection features make it ideal for ensuring safe and efficient battery operation in these demanding environments.
When designing with the L9988, it is important to consider the thermal performance of the TQFP80-EP package and ensure adequate PCB copper area for heat dissipation. Additionally, proper layout of the cell sense traces and careful selection of external components, such as balancing resistors and MOSFETs, are critical for achieving optimal performance and safety.
Drop-in alternatives for L9988 — 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 L9988 (same form factor and footprint) — differing in Package.
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L9788
⚡ Same Package ⚠️ Specs Unverified✓ In Stock
$2.7 / Unit
View Datasheet →L9988 Specifications
| Number of Cells | 4 series-connected cells |
| Cell Voltage Measurement Range | 0 V to 5 V |
| Total Measurement Error | < 2 mV |
| Balancing Method | Timed and PWM-based odd-even passive balancing |
| ADC Type | Dedicated high-precision ADCs (synchronous acquisition) |
| NTC Inputs | 4 analog inputs |
| General Purpose I/O | 2 |
| Power Supply | Direct from battery stack |
| Integrated Regulators | Programmable voltage regulators for MCU, CAN, NTCs |
| Predriver | Dual predriver for two groups of back-to-back MOSFETs |
| Safety Level | Up to ASIL-D targets |
| Package | TQFP80-EP (exposed pad) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
L9988 Pin Configuration
| Pin 1 | VCELL1 — Cell 1 voltage sense input |
| Pin 2 | VCELL2 — Cell 2 voltage sense input |
| Pin 3 | VCELL3 — Cell 3 voltage sense input |
| Pin 4 | VCELL4 — Cell 4 voltage sense input |
| Pin 5 | GND — Ground |
| Pin 6 | VCC — Power supply (from battery stack) |
| Pin 7 | NTC1 — NTC thermistor input 1 |
| Pin 8 | NTC2 — NTC thermistor input 2 |
| Pin 9 | NTC3 — NTC thermistor input 3 |
| Pin 10 | NTC4 — NTC thermistor input 4 |
| Pin 11 | GPIO1 — General purpose I/O 1 |
| Pin 12 | GPIO2 — General purpose I/O 2 |
| Pin 13 | CB1_DRV — Circuit breaker 1 predriver output |
| Pin 14 | CB2_DRV — Circuit breaker 2 predriver output |
| Pin 15 | CAN_TX — CAN transmit |
| Pin 16 | CAN_RX — CAN receive |
Typical Applications
L9988 is suitable for 6 applications: Automotive 12V Li-Ion Battery Pack, Industrial Battery Backup Systems, Start-Stop Systems, Mild Hybrid Electric Vehicles, Energy Storage Systems, Portable Power Tools.
Automotive 12V Li-Ion Battery Pack
The L9988 is designed for 12V Li-Ion battery packs in automotive applications, such as start-stop systems and mild hybrids. It monitors up to 4 cells with high accuracy (<2 mV error), provides passive balancing, and integrates protection features to achieve ASIL-D safety levels. The device can be powered directly from the battery stack and includes programmable regulators for system components, making it a complete BMS solution.
Recommended
Industrial Battery Backup Systems
The L9988 can be used in industrial battery backup systems where reliable monitoring and protection of Li-Ion packs are critical. Its high-precision ADCs and synchronous acquisition ensure accurate state-of-charge estimation, while the integrated balancing and protection functions extend battery life and prevent unsafe conditions. The device's wide cell voltage range (0-5V) supports various battery chemistries.
Recommended
Start-Stop Systems
In start-stop systems, the L9988 manages the 12V Li-Ion battery that powers the vehicle's electrical system during engine stop phases. The device's fast and accurate cell monitoring ensures the battery is always within safe operating limits, while the dual predriver controls the circuit breaker MOSFETs to disconnect the pack in fault conditions. Its ASIL-D capability meets automotive safety requirements.
Recommended
Mild Hybrid Electric Vehicles
The L9988 is suitable for mild hybrid electric vehicles (MHEVs) that use a 12V Li-Ion battery for regenerative braking and power assist. The device's high-precision measurement and balancing capabilities ensure optimal battery performance and longevity. Its integrated protection features and ASIL-D compliance make it a reliable choice for automotive-grade BMS.
Recommended
Energy Storage Systems
The L9988 can be used in small-scale energy storage systems (ESS) that require reliable battery management for 12V Li-Ion packs. Its ability to monitor up to 4 cells with high accuracy and perform passive balancing helps maintain pack health and safety. The device's programmable regulators can power the system MCU and communication interfaces, simplifying system design.
Recommended
Portable Power Tools
The L9988 can be used in portable power tools that use 12V Li-Ion battery packs. Its compact TQFP80-EP package and integrated features make it suitable for space-constrained designs. The device's protection functions, including overcurrent and overvoltage protection, ensure safe operation in demanding tool applications.
Recommended
Engineering reference data for L9988 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | L9788 |
|---|---|---|
| Package | TQFP80-EP | TQFP80-EP (assumed) |
| Brand | STMicroelectronics | STMicroelectronics |
| Price (1pc) | $8.50 | $4.44 |
Key Differentiators
- High measurement accuracy (vs L9788)
- ASIL-D safety level (vs L9788)
- Integrated dual predriver (vs L9788)
Design Notes
The L9988 is packaged in a TQFP80-EP with an exposed thermal pad. Ensure the PCB has a solid thermal connection to the pad, with multiple vias to a ground plane for heat dissipation. The power dissipation depends on the balancing current and regulator loads; calculate the junction temperature rise and keep it within the maximum rating.
For accurate cell voltage measurement, route the sense traces as differential pairs with proper filtering (e.g., RC filters) to reduce noise. Keep the traces short and away from high-current paths. Place the balancing resistors and MOSFETs close to the IC to minimize parasitic inductance.
Ensure the battery stack voltage does not exceed the absolute maximum rating of the L9988. Use appropriate protection on the power supply pins. When using the integrated regulators, verify that the total current draw does not exceed the regulator's capability. Also, configure the balancing algorithm correctly to avoid over-discharging individual cells.
Compliance Information
RoHS compliance confirmed from JLCPCB listing. Other compliance information not available in the provided data.
