STMicroelectronics L9965P Automotive Single-Channel Pyro-Fuse Drivers
STMicroelectronics L9965P Automotive Single-Channel Pyro-Fuse Drivers are designed to rapidly disconnect high-voltage battery lines during short circuits or vehicle collisions. The devices feature a dual-FET output stage with closed-loop current feedback for controlled pyro-fuse deployment. Programmable firing profiles allow designers to configure current levels and deployment durations for various igniter types.
The STMicroelectronics L9965P supports trigger activation through SPI commands or dedicated digital inputs compatible with level- and Pulse Width Modulation (PWM)-encoded signals. An integrated boost regulator charges an energy reserve capacitor to ensure reliable deployment, even during battery-loss conditions. Multiple auto-retry attempts and autonomous diagnostic routines help maximize system safety and deployment reliability.
Designed for automotive battery systems, these devices are AEC-Q100 Grade 1 qualified and ready for ISO 26262 ASIL-D functional safety applications. Deep-sleep current consumption is less than 10µA, helping reduce power usage during standby operation. Typical applications include battery disconnect systems in battery-electric vehicles (BEVs) and plug-in hybrid vehicles (PHEVs), backup energy storage systems, and UPS equipment.
Features
- AEC-Q100 Grade 1 qualified
- Very low power consumption
- Less than 10μA in deep-sleep mode (only trigger detection enabled)
- Less than 4mA in low-power mode (trigger detection enabled, ER boost recharge active, cyclic diagnostics every 100ms)
- Boost regulator to charge Energy Reserve (ER) with bang-bang control to reduce consumption
- FENH/FENL digital input triggers, compatible with level or PWM signals (16kHz and 125kHz), with line integrity check feature
- Autonomous cyclic diagnostic routine to ensure detection of all failures which may prevent safe deployment and/or cause inadvertent deployment
- Programmable deployment profile - current value and time duration can be adapted to different pyro-fuse igniters
- Firing strategy supporting multiple retry attempts based on user-selectable FIRE_GOOD signal
- Embedded NVM for configuration parameters storage and runtime configuration integrity check
- Easy integration with L9965C companion CSA, implementing many of the safety mechanisms needed to achieve safety targets, thus allowing easy L9965P plug-and-play in the system
- Pyro-fuse deployment available down to a minimum operating battery voltage of 6V
- 24-bit peripheral SPI for direct MCU/L9965C interface
- Compatible with pyro-fuses certified according to LV-16 and USCAR-28
- Fully ISO26262 compliant and ASIL-D systems ready
- Package options
- 5mm x 5mm x 0.9mm VFQFN32+4L
- 7mm x 7mm x 1mm TQFP32L
Applications
- High-voltage battery packs for BEVs and PHEVs
- Backup energy storage systems
- UPS systems
- Battery disconnect systems
Specifications
- 6V to 26V ERBST, ERDCHSW, PS, and VBATMON operating voltage range
- 3V to 5.5V VIO supply range
- Current consumption
- <10µA (typical) maximum deep-sleep
- 2.4mA maximum normal mode
- Pyro-Fuse deployment
- Programmable deployment currents
- 1.50A to 1.91A (I_DEPLOY_00)
- 1.75A to 2.23A (I_DEPLOY_01)
- 2.00A to 2.55A (I_DEPLOY_10)
- 3.50A to 4.46A (I_DEPLOY_11)
- 16µs typical deployment timer resolution
- 2032µs maximum deployment duration
- 0.7Ω maximum high-side switch on-resistance
- 0.5Ω maximum low-side switch on-resistance
- Auto-retry capability - 1 to 4 deployment attempts
- 0.5ms, 1ms, 1.5ms, or 2ms retry delay options
- Programmable deployment currents
- Boost regulator
- 18V to 24V programmable ERBST output voltage
- 1.6MHz to 2.4MHz switching frequency
- 1.8W to 2.6W boost input power limit
- 330mA to 480mA peak current limit
- 0.1mF to 1.2mF external capacitor range
- Diagnostics and safety functions
- Analog Built-In Self-Test (ABIST)
- Hardware Self-Check (HWSC)
- Pyro igniter resistance measurement
- Leakage detection on PF/PR outputs
- Deployment FET verification test
- Ground-loss monitoring (PGND and BSTGND)
- Oscillator monitoring and integrity checking
- NVM CRC and configuration integrity monitoring
- FAULTN output with integrity-check pulse generation
- SPI interface
- 24-bit SPI interface
- 2MHz maximum clock frequency
- 5-bit CRC (x5+x2+1 polynomial)
- CPOL = 0, CPHA = 1
- Junction-to-ambient thermal resistance
- 29.4°C/W for the TQFP32 package
- 35°C/W for the VFQFN32 package
- ±100mA ESD latch-up current test
- -40°C to +125°C operating temperature range
- -40°C to +150°C junction temperature range
Application Notes
- AN6194 - Single Channel Pyrofuse Driver
Block Diagram
Device functional states (FSM)
Development Tools
STMicroelectronics EVL9965P-N/EVL99BM2P-FN Promotional Boards
Provides the user with a platform to evaluate the L9965P/L99BM2P devices in a QFN package.
Complete Your Design
STMicroelectronics Standard Products
A broad range of drop-in replacements for general-purpose analog ICs, discretes, and serial EEPROMs.