Overview
The L9780 is an integrated circuit (IC) designed by STMicroelectronics to interface with a variety of wide range air fuel sensors. This device is specifically engineered to manage the oxygen pump of the air fuel sensor using a voltage-controlled current source (VCCS). The VCCS reference is generated by a PI controller with an external compensation network, allowing the device to adapt to different sensors. The user can select between two different compensation networks using the SPI interface. The L9780 is fully compatible with most air fuel sensors on the market and features an internal timing state machine that automates the measurement process sequencing. Additionally, it controls an external FET for the sensor heater and provides diagnostic capabilities via SPI.
Key Specifications
| Specification | Details |
|---|---|
| Package | 48-pin LQFP (7x7x1.4 mm) |
| Technology | BCD5s_70 V |
| Voltage Supply | 4.9V ~ 5.1V |
| Operating Temperature | -40°C ~ 125°C |
| Internal Oscillator | 4 MHz |
| Internal Supply | -5 V |
| Digital I/O Compatibility | 5 V or 3.3 V |
| RoHS Compliance | Ecopack2 (ROHS3 Compliant) |
Key Features
- Voltage controlled current source (VCCS) pump cell driver with selectable voltage clamp, offset compensation, diagnostic (short to battery), and 2 output channels
- Impedance measurement of reference cell
- 10-bit multiplexed A/D converter
- Scaling amplifier with sample & hold and offset compensation
- Control voltage amplifier with sample & hold and offset compensation
- Synchronous or asynchronous functionality selectable via SPI
- Heater FET driver with diagnostic (short to battery, short to ground, open circuit)
- 4 possible levels for clean current
- SPI with fault detection
- Digital input and outputs compatible with 5 V or 3.3 V voltage supply
- 2 channels available to connect compensation networks
- Short to battery diagnostic on functional ground (pin SR) and voltage from reference cell (pin INRC)
Applications
The L9780 is primarily designed for automotive applications, specifically for interfacing with wide range air fuel sensors. It is used in the powertrain system to manage the oxygen pump and heater of the air fuel sensor, ensuring accurate and reliable measurements. The device's compatibility with various sensors and its advanced diagnostic features make it a robust solution for automotive systems.
Q & A
- What is the primary function of the L9780 IC?
The L9780 IC is designed to interface with wide range air fuel sensors, managing the oxygen pump and heater of the sensor. - What type of package does the L9780 come in?
The L9780 comes in a 48-pin LQFP (7x7x1.4 mm) package. - What is the operating temperature range of the L9780?
The operating temperature range of the L9780 is -40°C to 125°C. - How does the L9780 adapt to different sensors?
The L9780 adapts to different sensors using a PI controller with an external compensation network, which can be selected via the SPI interface. - What diagnostic capabilities does the L9780 offer?
The L9780 offers diagnostic capabilities for shorts to battery, shorts to ground, and open circuits, as well as heater diagnostics, all accessible via SPI. - Is the L9780 compatible with 5 V and 3.3 V voltage supplies?
Yes, the digital input and outputs of the L9780 are compatible with both 5 V and 3.3 V voltage supplies. - What is the purpose of the internal timing state machine in the L9780?
The internal timing state machine automatically manages the sequencing of the measurement process. - How can the main time values be configured in the L9780?
The main time values can be configured using the SPI interface. - What is the role of the heater FET driver in the L9780?
The heater FET driver controls the sensor heater and includes diagnostic capabilities for shorts to battery, shorts to ground, and open circuits. - Is the L9780 RoHS compliant?
Yes, the L9780 is RoHS compliant (Ecopack2 and ROHS3 compliant).
