L9966CB-TR - 15-Channel Automotive FlexInput Sensor IC | ST
Référence : L9966CB-TR ✓ ActifL9966CB-TR Présentation
A sensor interface IC (also called a mixed-signal front end or sensor conditioning ASIC) sits between physical sensors and the vehicle's electronic control unit. It converts weak, non-standard sensor signals into standardized digital data, applies excitation, biasing, filtering and diagnostics, and reports status back to the host processor. In the product hierarchy it belongs to the family of interface ICs, which sit between sensors and microcontrollers within automotive electronic control units and powertrain/body electronics.
Key features of the L9966 include up to 15 available input channels for analog sensing, resistance measurement and digital sensing of temperature, lambda, pressure and position sensors, plus a 36 V SPI interface rated for protected battery supply domains. The device also embeds a bandgap reference, a main oscillator, voltage monitoring, a logic section with SYNC, RST and INT handling, and internal current generators, along with a 3.3 V signal domain that allows the status of the internal 3V3 signals to be read back.
Internally, the architecture separates ECU-side supply pins from local sensor pins and includes dedicated blocks such as internal current generators, the resistance-measurement block, ground-reference and analog-output blocks, with a UBSW supply pin able to place the device into a low-power state while keeping the configuration register content and bandgap reference active. A power-on-reset event is generated when the UBSW rail falls below the power-on-reset threshold.
Typical applications include engine management sensor acquisition, exhaust lambda and NOx sensing, crankshaft and camshaft position sensing, throttle and pedal position conditioning, battery and coolant temperature measurement, pressure sensor interfaces, and body/thermal management modules where a single IC replaces a large number of discrete signal-conditioning components.
When designing with the L9966, pay attention to the protected battery supply pins versus local ECU pins, ensure the R_GND connection to ground on the PCB is continuous, and select external resistor and capacitor values strictly from the application information in the manufacturer datasheet. Keep the exposed pad tied to ground with a full thermal via array to keep junction temperature under control.
This page consolidates manufacturer datasheet detail, cross-reference results, a parameter comparison table and practical design guidance so that engineers can evaluate the L9966CB-TR, and its drop-in alternatives, before requesting a quote or committing a layout.
Alternatives de remplacement direct pour L9966CB-TR — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Variantes de cette série
Modèles de la même série directement compatibles avec L9966CB-TR (même facteur de forme et même empreinte) — différant par Package.
L9966CB
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
L9966
✅ Remplacement directContactez-nous pour le prix
Voir la fiche technique →L9966C
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
L9966CB-TR Valeurs maximales et caractéristiques électriques
| Device Type | FlexInput IC for automotive applications |
| Manufacturer | STMicroelectronics |
| Order Code | L9966CB-TR |
| Automotive Qualification | AEC-Q100 qualified |
| Supported System Voltage | 12 V and 24 V systems |
| Operating Battery Supply Voltage | 5.5 V to 36 V |
| SPI Interface Supply Rating | 36 V SPI interface |
| Number of Available Channels | Up to 15 channels |
| Analog Sensing Channels | Supported |
| Resistance Measurement | Supported (RRS block) |
| Digital Sensing | Supported for temperature, lambda, pressure and position sensors |
| Host Interface | SPI with SYNC, RST and INT logic signals |
| Internal Reference | Bandgap reference |
| Internal Oscillator | Main oscillator |
| Voltage Monitoring | Internal voltage monitoring and power-on reset |
| Internal Current Generators | Present, switched off in low-power mode |
| Low-Power Supply Pin | UBSW pin with VPOR threshold |
| Boîtier | TQFP-48 (7x7 mm) with exposed pad |
| Type de montage | Surface Mount |
| Packing | Tape and Reel |
| Operating Voltage Class | Protected battery supply domains |
| Datasheet Length | 122 pages |
Guide de configuration des broches du L9966CB-TR tqfp-48 (7x7 mm) with exposed pad
Configuration des broches du L9966CB-TR (boîtier tqfp-48 (7x7 mm) with exposed pad). La numérotation des broches, les fonctions et les schémas de connexion sont définis dans la fiche technique du fabricant. Consultez-la pour l'empreinte exacte et les directives de soudage.
Aucune donnée de brochage détaillée disponible pour L9966CB-TR.
Consultez la fiche technique pour la configuration complète des broches.
Applications typiques
L9966CB-TR convient pour 6 applications: Engine Management Sensor Acquisition, Exhaust Lambda and NOx Sensing, Battery and Thermal Management Modules, Vehicle Position and Pedal Sensor Interfaces, Industrial and Off-Highway Sensor Nodes, Test and Measurement Sensor Conditioning.
Engine Management Sensor Acquisition
The L9966CB-TR consolidates crank, cam, throttle and rail pressure sensing into one AEC-Q100 qualified front end. Up to 15 channels can be assigned to analog sensing, resistance measurement or digital sensor types, so an ECU can read resistive sensors such as rail-pressure or coolant-temperature probes alongside switch-based position sensors on the same PCB. Because the SPI interface tolerates 36 V, the digital lines can remain in the protected battery supply domain and be read directly by the host MCU, while the internal current generators supply sensor excitation without external sources. The result is a smaller control-unit PCB, fewer discrete conditioning networks and a single SPI transaction set for diagnostics.
Recommandé
Exhaust Lambda and NOx Sensing
Wideband and narrowband exhaust oxygen sensors are notoriously difficult to condition because the signal level, impedance and temperature range vary widely. The L9966CB-TR provides dedicated digital sensing channels specifically intended for temperature, lambda and pressure sensors, together with resistance measurement and internal current generators for excitation. Running the sensing front end in the same protected supply domain as the sensor reduces harness wiring complexity and improves common-mode rejection against the ignition and injector noise of a running engine. The 48-pin TQFP with exposed pad also keeps the analog and digital sections thermally together for stable offset behaviour across wide ambient temperatures.
Recommandé
Battery and Thermal Management Modules
Battery management systems need to measure pack temperatures at many points and combine them with current-sensor and voltage inputs. With up to 15 channels available, the L9966CB-TR can absorb the thermistor strings, pack voltage taps and contactor position switches without adding a separate multiplexer board. The internal bandgap reference and voltage monitoring block give the host MCU a consistent reference and early warning of supply anomalies, while the 5.5 V to 36 V battery supply range covers both 12 V and 24 V packs with transient margin. Low-power behaviour, where the current generators and analog blocks shut down while configuration is retained, supports sleep modes during key-off operation.
Recommandé
Vehicle Position and Pedal Sensor Interfaces
Throttle, accelerator pedal, brake and gear-position sensors mix potentiometric analog outputs with discrete switch contacts and ratiometric excitation. The L9966CB-TR handles analog sensing, resistance measurement and digital sensing on the same configurable channel set, so one device covers a pedal module that mixes a potentiometer track with a switch-based kick-down contact. The 36 V-rated SPI interface lets the module communicate over a short harness to the body or chassis controller without level-shifting the logic to 3.3 V, which reduces connector pin count and improves robustness against ground-offset errors in the vehicle body. The device is AEC-Q100 qualified for use directly in harsh cabin and underhood environments.
Recommandé
Industrial and Off-Highway Sensor Nodes
The L9966CB-TR translates well beyond passenger vehicles. Its 5.5 V to 36 V operating battery supply and 36 V SPI interface suit off-highway machinery, agricultural equipment and heavy trucks running 24 V systems with severe load-dump events. Up to 15 mixed sensing channels let one node replace a resistive divider field, a multiplexer and a discrete ADC front end for pressure, temperature and position sensing on hydraulic or agricultural implements. The small 7x7 mm TQFP with exposed pad fits space-constrained sensor modules, and the internal bandgap reference plus voltage monitoring support robust self-diagnostics for field maintenance.
Recommandé
Test and Measurement Sensor Conditioning
In end-of-line and production test fixtures, the L9966CB-TR can act as a stand-alone sensor interface for verifying resistive, analog and digital sensor families against a common SPI protocol. Because the configuration registers are retained even when the current generators and analog blocks are switched off, a fixture can preset the channel configuration and then cycle through the power state for deep functional testing of the ECU under test. The internal voltage monitoring and power-on-reset behaviour make it straightforward to detect supply marginality in a production fixture. Bringing sensor conditioning and the digital interface into one AEC-Q100 qualified package simplifies test-fixture wiring and reduces the number of instruments needed per station.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour L9966CB-TR — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | L9966CB | L9966 | L9966C |
|---|---|---|---|---|
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics |
| Package | TQFP-48 (7x7 mm) with exposed pad | TQFP-48 (7x7 mm) with exposed pad - same | TQFP-48 (7x7 mm) with exposed pad - same | TQFP-48 (7x7 mm) with exposed pad - same |
| Automotive Qualification | AEC-Q100 qualified | AEC-Q100 qualified | AEC-Q100 qualified | AEC-Q100 qualified |
| Operating Battery Supply Voltage | 5.5 V to 36 V | 5.5 V to 36 V | 5.5 V to 36 V | 5.5 V to 36 V |
| System Voltage Compatibility | 12 V and 24 V systems | 12 V and 24 V systems | 12 V and 24 V systems | 12 V and 24 V systems |
| Supported Sensing Types | Analog, resistance measurement and digital sensing (temperature, lambda, pressure, position) | Analog, resistance measurement and digital sensing | Analog, resistance measurement and digital sensing | Analog, resistance measurement and digital sensing |
| Host Interface | SPI with SYNC, RST and INT, 36 V rated | SPI with SYNC, RST and INT | SPI with SYNC, RST and INT | SPI with SYNC, RST and INT |
Principaux différenciateurs
- Highest channel density in the ST FlexInput family for mixed sensor types (vs L9966C)
- Exact same-footprint substitution with identical electrical behaviour (vs L9966CB)
- 36 V-rated SPI interface removes the need for external level shifting (vs L9966CB)
- Configurable low-power behaviour that preserves diagnostics (vs L9966C)
Notes de conception
Keep the exposed pad of the 48-pin TQFP tied to ground with a full array of thermal vias, and route the R_GND connection to ground as a dedicated low-impedance track. If the PCB connection for R_GND is lost, the reference shifts one diode voltage drop above ground, which silently corrupts every resistance-measurement result. Use the pin-class legend in the manufacturer datasheet to separate ECU internal pins, protected supply pins and local sensor pins before assigning tracks, and place the sensor return path away from injector and ignition return currents.
The UBSW rail is the low-power supply pin, and when it drops below the power-on-reset threshold the device generates a POR event. Size the decoupling on UBSW and the protected battery supply pins for the maximum transient in the target platform, since a spurious POR clears the working state of the acquisition chain. Note that the internal current generators, resistance-measurement block, ground-reference block and analog-output block are shut down in low-power mode while register configuration is retained, so power sequences that rely on sensor excitation must allow enough wake time before the first conversion.
Because the SPI interface is rated for 36 V, the digital communication lines can remain in the protected battery supply domain instead of being shifted to 3.3 V, which removes a level-shifter stage and reduces connector pin count. Keep the SPI clock, data and the SYNC, RST and INT lines away from the sensor excitation returns and from injector drivers, and provide a solid ground reference for the SPI return path. The internal bandgap reference and main oscillator remain active in low-power mode so the 3V3 signal status can be read back, which makes a read of the internal diagnostics a valid check of the interface before starting a measurement sequence.
The 48-pin TQFP (7x7 mm) relies on its exposed pad for heat spreading, so the board stack-up and copper area around the pad dominate the junction temperature. Estimate the dissipation from the sensor excitation power plus the logic load in your worst-case channel configuration, and confirm that the exposed-pad via array meets the thermal requirements of the package outline drawing. Operating temperature margin in an underhood ECU is usually tighter than in a bench fixture, so validate the junction estimate at maximum ambient with all channels active rather than in idle conditions.
Informations de conformité
The ST L9966 datasheet states that the device is AEC-Q100 qualified for automotive applications and compatible with 12 V and 24 V systems. RoHS, REACH, lead-free and halogen-free status are not stated in the available documentation; check the current ST product page for the latest declarations.
