33972

Features:

• Designed to Operate 5.5 V VPWR 26 V
• Switch Input Voltage Range -14 V to VPWR, 40 V Max
• Interfaces Directly to Microprocessor Using 3.3 V/5.0 V SPI Protocol
• Selectable Wake-Up on Change of State
• Selectable Wetting Current (16 mA or 2.0 mA)
• 8 Programmable Inputs (Switches to Battery or Ground)
• 14 Switch-to-Ground Inputs
• VPWR Standby Current 100 µA Typical, VDD Standby Current 20 µA Typical
• Active Interrupt (INT ) on Change-of-Switch State
• Pb-Free Packaging Designated by Suffix Code EW


Pinout




Specifications

Rating	Symbol	Value	Unit
ELECTRICAL RATINGS
VDD Supply Voltage		-0.3 to 7.0	VDC
CS, SI, SO, SCLK, INT , AMUX (Note 1)		-0.3 to 7.0	VDC
WAKE (Note 1)		-0.3 to 40	VDC
VPWR Supply Voltage (Note 1)		-0.3 to 50	VDC
Switch Input Voltage Range		-14 to 40	VDC
Frequency of SPI Operation (VDD = 5.0 V)		6.0	MHz
ESD Voltage (Note 2) Human Body Model (Note 3), (Note 4) Machine Model (Note 5)	VESD1 VESD2	±4000 ±200	V
THERMAL RATINGS
Operating Temperature Ambient Junction Case	TA TJ TC	-40 to 125 -40 to 150 -40 to 125
Storage Temperature	TSTG	-55 to 150
Power Dissipation (TA = 25) (Note 6)	PD	1.7	W
Thermal Resistance Junction to Ambient Junction to Lead	RJA RJL	74 25	/W
Peak Package Reflow Temperature During Solder Mounting (Note 7) DWB Suffix EW Suffix	TSOLDER	240 245

Description

The 33972 Multiple Switch Detection Interface with Suppressed Wake-Up is designed to detect the closing and opening of up to 22 switch contacts. The switch status, either open or closed, is transferred to the microprocessor unit (MCU) through a serial peripheral interface (SPI). The device also features a 22-to-1 analog multiplexer for reading inputs as analog. The analog input signal is buffered and provided on the AMUX output terminal for the MCU to read.

The 33972 device has two modes of operation, Normal and Sleep. Normal mode allows programming of the device and supplies switch contacts with pullup or pulldown current as it monitors switch change of state. The Sleep mode provides low quiescent current, which makes the 33972 ideal for automotive and industrial products requiring low sleep state currents.