mc33975 Freescale Semiconductor, Inc, mc33975 Datasheet - Page 11

• Manufacturer Part Number: mc33975
• Description: Multiple Switch Detection Interface With Suppressed Wake-up And 32ma Wetting Current
• Manufacturer: Freescale Semiconductor, Inc

Analog Integrated Circuit Device Data
Freescale Semiconductor
SGn
VPWR
VDD
WAKE
INT
CS
SGn
CS
INT
SGn Bit in SPI Word
Normal Mode
Power-Up
SCLK
CS
SO
SI
(Disable Tri-State)
Command
Tri-State
t
SO(EN)
0.2 VDD
Command
Switch
Status
0.2
0.7 VDD
Latch switch status
on falling edge of CS
1
Command
VD
Sleep
0.7 VDD
0.2 VDD
t
0.2 VDD
0.7 VDD
LEAD
D
Figure 5. Sleep Mode to Normal Mode Operation
t
Command
SI(SU)
Figure 6. Normal Mode Interrupt Operation
Switch
Status
MSB in
MSB out
Sleep Mode
0
Figure 4. SPI Timing Characteristics
t
SI(HOLD)
TIMING DIAGRAMS
Command
Switch
Status
Normal
0
Mode
Wake-Up From Interrupt
Timer Expire
Switch state change with
CS
low generates INT
Rising edge of CS does not
clear
occurred while CS was low
Switch closed “1”
Sleep Command
INT
Command
Switch
Status
because state change
t
VALID
1
Sleep Mode
Command
Switch
Status
LSB out
ELECTRICAL CHARACTERISTICS
1
t
LAG
Normal
Mode
Switch state change with
CS
Wake-Up From
Closed Switch
low generates INT
Switch open “0”
TIMING DIAGRAMS
Sleep Command
Command
Switch
Status
t
0
SO(DIS)
33975
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