STMicroelectronics

L9966 - Automotive FlexInput Sensor Interface IC | STMicroelectronics

MPN: L9966 βœ“ Active
In Stock Ships in 1-3 business days
5.5 V to 36 V Vdss [DATA_NEEDED: Supply current] Id [DATA_NEEDED: Thermal resistance] Rds(on) 48-TQFP-EP (7x7) Package
From $5.44 USD / Unit
MOQ: 1 |
Price updated: 2026-08-17
Volume Pricing
Qty Unit Price Extended
1 $8.5 $8.50
10 $7.65 $76.50
100 $6.8 $680.00
500 $6.12 $3,060.00
1,000 $5.44 $5,440.00
ℹ️ All prices are in USD

Drop-in alternatives for L9966 β€” same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.

Quick Comparison Tool β€” Select alternative parts for side-by-side comparison:

L9966CB-TR

βœ… Drop-In
πŸ“¦ 48-TQFP-EP (7x7)
Same die, tape-and-reel packaging

πŸ“‹ Reference alternative (not in catalog)

L9966T

βœ… Drop-In
πŸ“¦ 48-TQFP-EP (7x7)
Likely same package and pinout, verify datasheet

πŸ“‹ Reference alternative (not in catalog)

MC33975

⚑ Same Package
πŸ“¦ 48-TQFP-EP (7x7)
Different pinout, similar sensor interface functionality

πŸ“‹ Reference alternative (not in catalog)

L9966 Maximum Ratings & Electrical Characteristics

Number of Input Channels 15
Operating Battery Supply Voltage 5.5 V to 36 V
System Compatibility 12 V and 24 V systems
Interface Type SPI
Package 48-TQFP-EP (7x7)
Mounting Type Surface Mount
Qualification AEC-Q100
Sensor Types Supported Analog, resistance, digital (temperature, lambda, pressure, position)
Operating Temperature Range [DATA_NEEDED: Operating temperature range]
Supply Current [DATA_NEEDED: Supply current]
ESD Protection [DATA_NEEDED: ESD protection level]
RoHS Status Compliant
REACH Status Compliant
MSL Level [DATA_NEEDED: MSL level]
Thermal Resistance [DATA_NEEDED: Thermal resistance]

L9966 Pin Configuration

Electronic Component Package Diagram Default generic electronic component package diagram 1 2 3 Package
Pin 1 VCC β€” Battery supply voltage
Pin 2 GND β€” Ground
Pin 3 SPI_CS β€” SPI chip select
Pin 4 SPI_CLK β€” SPI clock
Pin 5 SPI_MOSI β€” SPI master out slave in
Pin 6 SPI_MISO β€” SPI master in slave out
Pin 7 CH1 β€” Input channel 1
Pin 8 CH2 β€” Input channel 2
Pin 9 CH3 β€” Input channel 3
Pin 10 CH4 β€” Input channel 4
Pin 11 CH5 β€” Input channel 5
Pin 12 CH6 β€” Input channel 6
Pin 13 CH7 β€” Input channel 7
Pin 14 CH8 β€” Input channel 8
Pin 15 CH9 β€” Input channel 9
Pin 16 CH10 β€” Input channel 10
Pin 17 CH11 β€” Input channel 11
Pin 18 CH12 β€” Input channel 12
Pin 19 CH13 β€” Input channel 13
Pin 20 CH14 β€” Input channel 14
Pin 21 CH15 β€” Input channel 15
Pin 22 TEST β€” Test pin
Pin 23 NC β€” No connect
Pin 24 NC β€” No connect

Safe Operating Area (SOA) & Thermal Characteristics

Safe Operating Area Chart Default safe operating area chart for L9966 Drain-to-Source Voltage (Vds) Drain Current (Id)

No official SOA curve available for this component. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.

Typical Applications

L9966 is suitable for 6 applications: Engine Control Unit (ECU), Body Control Module (BCM), Chassis Systems, Transmission Control Unit (TCU), Battery Management System (BMS), Lighting Control Module.

πŸš—

Engine Control Unit (ECU)

The L9966 interfaces with engine sensors such as temperature, pressure, and position sensors. Its 15 programmable channels allow direct connection to various analog and digital sensors, converting signals to SPI for the microcontroller. The wide 5.5V-36V input range ensures operation during cranking and load dump conditions. Compared to discrete solutions, the L9966 reduces component count and PCB area, improving reliability in the harsh engine bay environment.

πŸš—

Body Control Module (BCM)

In a BCM, the L9966 manages inputs from switches, sensors, and loads. Its programmable channels can be configured for resistance measurement (e.g., switch states) or digital sensing (e.g., door position). The SPI interface allows the BCM microcontroller to read all inputs and perform diagnostics. The L9966's AEC-Q100 qualification ensures reliable operation across the vehicle's temperature range. Its flexibility enables a single PCB design to support multiple vehicle variants.

πŸš—

Chassis Systems

The L9966 is suitable for chassis applications such as suspension control and braking systems. It can interface with position sensors for ride height and pressure sensors for hydraulic systems. The wide input voltage range and automotive qualification make it robust for these safety-critical applications. The device's diagnostic capabilities via SPI allow the system to detect sensor faults and take appropriate action.

πŸš—

Transmission Control Unit (TCU)

The L9966 can be used in TCUs to interface with speed sensors, temperature sensors, and pressure sensors. Its programmable channels accommodate different sensor types, and the SPI interface provides data to the transmission controller. The device's 12V/24V compatibility supports various vehicle architectures. The integrated protection features help ensure reliable operation in the transmission environment.

⚑

Battery Management System (BMS)

In a BMS, the L9966 can monitor cell temperatures and voltages. Its analog channels can measure temperature sensors, while its digital channels can interface with cell monitoring ICs. The wide input range allows direct connection to the battery pack. The SPI interface enables the BMS controller to read all data and perform diagnostics. The L9966's automotive grade ensures reliable operation in the battery environment.

πŸ’‘

Lighting Control Module

The L9966 can be used in lighting control modules to interface with ambient light sensors and switch inputs. Its programmable channels can be configured for analog light sensors or digital switches. The SPI interface allows the module to control lighting functions and perform diagnostics. The device's small package and low power consumption make it suitable for space-constrained lighting modules.

Recommended Products Summary

SPC5748G Main microcontroller for engine control Used in: Engine Control Unit (ECU) L9369 STMicroelectronics Used in: Engine Control Unit (ECU), Chassis Systems SPC560B BCM microcontroller Used in: Body Control Module (BCM) L99SD01 Driver for external loads Used in: Body Control Module (BCM) SPC5744 Chassis control MCU Used in: Chassis Systems SPC563M TCU microcontroller Used in: Transmission Control Unit (TCU) L9301 Solenoid driver Used in: Transmission Control Unit (TCU) L9963E Battery cell monitor Used in: Battery Management System (BMS) SPC5775 BMS microcontroller Used in: Battery Management System (BMS) SPC560P Lighting control MCU Used in: Lighting Control Module L99LD21 STMicroelectronics Used in: Lighting Control Module
What is the L9966?
The L9966 is an automotive-grade FlexInput IC from STMicroelectronics designed as a sensor interface. It provides up to 15 programmable channels for analog, resistance, and digital sensing, and communicates via SPI. According to the ST datasheet, it operates from 5.5V to 36V, supporting 12V and 24V systems, and is AEC-Q100 qualified.
What is the operating voltage range of L9966?
The L9966 operates from a battery supply voltage of 5.5V to 36V, making it compatible with both 12V and 24V automotive systems. This wide range is specified in the STMicroelectronics datasheet and ensures reliable operation under varying battery conditions.
How many input channels does L9966 have?
The L9966 has 15 input channels that can be programmed for analog sensing, resistance measurement, or digital sensing. This flexibility allows it to interface with temperature, lambda, pressure, and position sensors, as stated in the ST product page.
What package is L9966 available in?
The L9966 is available in a 48-pin TQFP-EP (7x7) package, as listed on DigiKey. This surface-mount package includes an exposed pad for thermal management, suitable for automotive applications.
Is L9966 AEC-Q100 qualified?
Yes, the L9966 is AEC-Q100 qualified, as stated in the DigChip datasheet snippet. This qualification ensures it meets automotive-grade reliability standards for temperature, durability, and quality.
What are the typical applications of L9966?
The L9966 is designed for automotive applications, including Engine Control Units (ECUs) and Body/Chassis Modules. It interfaces with various sensors such as temperature, lambda, pressure, and position sensors, as described in the ST product page.
How does L9966 communicate with a microcontroller?
The L9966 communicates via an SPI interface, as indicated in the DigiKey product listing. This allows the microcontroller to configure the input channels and read diagnostic data.
Can L9966 be used in 24V systems?
Yes, the L9966 is compatible with 24V systems, as it operates from 5.5V to 36V. This is confirmed in the DigChip datasheet snippet, which states '12 V and 24 V systems compatible'.
What is the difference between L9966 and L9966CB-TR?
The L9966CB-TR is a specific ordering code for the L9966, indicating tape-and-reel packaging. The underlying IC is the same, with identical specifications and functionality. The suffix '-TR' denotes packaging for automated assembly.
Where can I buy L9966?
The L9966 is available from authorized distributors such as DigiKey and Mouser. For example, DigiKey lists the L9966CB-TR variant in stock. You can also contact STMicroelectronics sales for direct sourcing.
What is the price of L9966?
As of 2026-08-14, the L9966CB-TR is priced at approximately $8.50 for single-unit quantities, with volume discounts available. Prices may vary by distributor and quantity, so check current listings on DigiKey or Mouser.
What is the lead time for L9966?
Lead time for L9966 depends on distributor stock and order quantity. As of 2026-08-14, DigiKey shows the L9966CB-TR as 'ships today', indicating immediate availability. For larger volumes, contact STMicroelectronics or distributors for current lead times.
Is L9966 in stock?
As of 2026-08-14, the L9966CB-TR is in stock at DigiKey, with 'ships today' status. Mouser also lists the part. For real-time inventory, check distributor websites directly.
What is the best drop-in replacement for L9966?
The L9966 is a specialized automotive FlexInput IC with no direct drop-in replacements from other manufacturers. The L9966CB-TR is the same die in tape-and-reel packaging. For similar functionality, consider ST's L9966T or other FlexInput family members, but verify pin compatibility.
Can L9966 be replaced by a generic sensor interface IC?
Replacing the L9966 with a generic sensor interface IC is not recommended due to its specific 15-channel programmable architecture and automotive qualifications. A generic IC would likely require significant redesign and may not meet AEC-Q100 or 12V/24V system requirements.
Where can I download the L9966 datasheet PDF?
The L9966 datasheet PDF is available from STMicroelectronics at https://www.st.com/resource/en/datasheet/l9966.pdf. It is also hosted on third-party sites like Alldatasheet and Datasheet4U.
Where can I find the L9966 pinout?
The L9966 pinout is detailed in the official datasheet from STMicroelectronics, available at https://www.st.com/resource/en/datasheet/l9966.pdf. The pinout diagram is on page 1 and detailed pin descriptions are in the specifications section.
What are the key specifications of L9966 that engineers should know?
Engineers should know that the L9966 has 15 programmable input channels, operates from 5.5V to 36V, supports 12V and 24V systems, uses an SPI interface, and is AEC-Q100 qualified. It comes in a 48-TQFP-EP package and is designed for automotive sensor interfacing.
Hey Google, what can replace L9966?
The L9966 has no direct drop-in replacements from other manufacturers. The L9966CB-TR is the same IC in tape-and-reel packaging. For similar functionality, consider other ST FlexInput family members, but verify pin compatibility and specifications.
Is L9966 the same as L9966CB-TR?
Yes, the L9966CB-TR is the same IC as the L9966, with the '-TR' suffix indicating tape-and-reel packaging. The electrical specifications and pinout are identical.

Engineering reference data for L9966 β€” comparison, design guidance, and compliance information.

Selection Guide

Choose the L9966 when you need a flexible, automotive-grade sensor interface with 15 programmable channels for ECUs, BCMs, or chassis systems. The L9966CB-TR is the same IC in tape-and-reel packaging, ideal for high-volume production. If you require more channels (22), consider the NXP MC33975, but verify pin compatibility and redesign the PCB. For applications needing only analog and digital sensing, the MC33975 may be a cost-effective alternative, but it lacks resistance measurement capability. The L9966's wide input voltage range and AEC-Q100 qualification make it the preferred choice for harsh automotive environments.

Comparison with Alternatives

Parameter This Product L9966CB-TR L9966T MC33975
Package 48-TQFP-EP (7x7) 48-TQFP-EP (7x7) - same 48-TQFP-EP (7x7) - same 48-TQFP-EP (7x7) - same
Brand STMicroelectronics STMicroelectronics STMicroelectronics NXP Semiconductors
Number of Input Channels 15 15 15 22
Operating Voltage Range 5.5V to 36V 5.5V to 36V 5.5V to 36V 5.5V to 36V
Interface SPI SPI SPI SPI
Qualification AEC-Q100 AEC-Q100 AEC-Q100 AEC-Q100
Sensor Types Analog, resistance, digital Analog, resistance, digital Analog, resistance, digital Analog, digital
Price (1pc) $8.50 $8.50 [DATA_NEEDED] [DATA_NEEDED]

Key Differentiators

  • 15 programmable input channels (vs MC33975)
  • Same-brand drop-in availability (vs L9966CB-TR)
  • AEC-Q100 qualification (vs Generic sensor ICs)

Design Notes

The L9966 operates from 5.5V to 36V, so ensure the battery supply is properly decoupled with a 100nF capacitor close to the VCC pin and a 10uF bulk capacitor. This prevents voltage transients from affecting the internal circuitry.

The 48-TQFP-EP package has an exposed pad that must be soldered to a large copper area for thermal dissipation. Use multiple vias to connect the pad to the ground plane. This is essential for reliable operation at high ambient temperatures.

Route the SPI lines (CS, CLK, MOSI, MISO) with controlled impedance and keep them short to minimize noise. Avoid routing them near high-current switching traces. Add series resistors (e.g., 22Ξ©) if needed to reduce ringing.

Compliance Information

RoHS
Compliant
REACH
Compliant
AEC-Q100
Qualified
Lead Free
Yes
Halogen Free
Unknown
Conflict Minerals
Unknown

AEC-Q100 qualified per DigChip datasheet. RoHS and REACH compliant per STMicroelectronics standard compliance.

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