Overview
The NXP MC33978AESR2 is a multiple switch detection interface (MSDI) designed to detect the closing and opening of up to 22 switch contacts. This SMARTMOS device is part of NXP's comprehensive range of interface solutions, particularly tailored for automotive and industrial applications. It communicates with a microprocessor unit (MCU) through a serial peripheral interface (SPI) and features a 24-to-1 analog multiplexer for reading input channels as analog inputs. The device also includes integrated battery and temperature monitoring capabilities, making it versatile and reliable for various use cases.
Key Specifications
| Parameter | Value |
|---|---|
| Number of Switch Contacts | Up to 22 |
| Supply Voltage Range | 4.5 V to 36 V (full parametric operation: 6.0 V to 28 V) |
| Switch Input Voltage Range | -1.0 V to 36 V |
| Programmable Wetting Current | 2, 6, 8, 10, 12, 14, 16, or 20 mA |
| Interface | SPI (3.3 V / 5.0 V) |
| Package Type | 32-QFN |
| Standby Current | Typical IBATP = 30 μA, IDDQ = 10 μA |
| Operating Modes | Normal and Low-power mode (LPM) |
Key Features
- Detection of up to 22 switch contacts with programmable wetting currents.
- 24-to-1 analog multiplexer for reading input channels as analog inputs.
- Integrated battery and temperature monitoring.
- Interfaces directly to an MCU using 3.3 V / 5.0 V SPI protocol.
- Selectable wake-up on change of state and active interrupt (INT_B) on change-of-switch state.
- Low-power mode (LPM) for reduced quiescent current.
- Eight programmable inputs (switches to battery or ground) and 14 switch-to-ground inputs.
Applications
The MC33978AESR2 is primarily used in automotive and industrial applications where multiple switch monitoring is crucial. It is suitable for systems that require reliable and efficient switch state detection, such as in vehicle control systems, industrial automation, and other applications where low power consumption and robust performance are essential.
Q & A
- What is the primary function of the MC33978AESR2?
The MC33978AESR2 is designed to detect the closing and opening of up to 22 switch contacts and communicate the switch status to a microprocessor unit (MCU) via SPI. - What is the supply voltage range for the MC33978AESR2?
The device operates within a supply voltage range of 4.5 V to 36 V, with full parametric operation between 6.0 V and 28 V. - What types of inputs does the MC33978AESR2 support?
The device supports eight programmable inputs (switches to battery or ground) and 14 switch-to-ground inputs. - How does the MC33978AESR2 interface with a microprocessor?
The device interfaces directly with an MCU using a 3.3 V / 5.0 V SPI protocol. - What are the key features of the MC33978AESR2's power management?
The device features a low-power mode (LPM) with a typical standby current of IBATP = 30 μA and IDDQ = 10 μA, making it suitable for applications requiring low sleep-state currents. - Does the MC33978AESR2 include any additional monitoring capabilities?
Yes, the device includes integrated battery and temperature monitoring capabilities. - What is the significance of the programmable wetting current in the MC33978AESR2?
The programmable wetting current (2, 6, 8, 10, 12, 14, 16, or 20 mA) allows for flexible configuration to meet various application requirements. - How does the MC33978AESR2 handle switch state changes?
The device provides selectable wake-up on change of state and an active interrupt (INT_B) on change-of-switch state. - What are the typical applications of the MC33978AESR2?
The device is used in automotive and industrial applications where reliable and efficient switch state detection is necessary. - What package type is the MC33978AESR2 available in?
The MC33978AESR2 is available in a 32-QFN package.
