接口 - 专用 Switch Detection Interface, 22-switches, 3.3 V / 5.0 V SPI , QFN32
Overview
The ® MC34978 is a multiple switch detection interface MSDI designed to detect the closing and opening of up to 22 switch contacts in industrial environments.
* The switch status, either open or closed, is transferred to the microprocessor unit through a serial peripheral interface SPI
* This SMARTMOS® device also features a 24-to-1 analog multiplexer for reading analog inputs
* Individually selectable input currents are available in Normal and Low-Power Mode LPM, as needed in the application
* A battery and temperature monitor are included in the IC and are available via the AMUX pin
* This product interfaces with any microcontroller that supports SPI communications
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## Features
* Designed to operate 4.5 V ≤ VBATP ≤ 36 V
* Switch input voltage range -14 V to VPWR, 36 V Max.
* Interfaces directly to an MCU using 3.3 V / 5.0 V SPI protocol
* Selectable wake-up on change of state
* Selectable wetting current 2, 6, 8, 10, 12, 14, 16, or 20 mA
* 8 programmable inputs switches to battery or ground and 14 switch-to-ground inputs
* Typical standby current - VBATP = 30 uA and VDD = 10 uA
* Integrated battery and temperature sensing
## Features