Datasheet

DS2408
30 of 39
Figure 20. DS2408 AS µC-OPERATED KEYBOARD SCANNER
VCC
10kΩ
10
9
8
7
6
5
4
3
2
1
10U
DS2408
P0
2
P1
14
P2
13
P3
12
P4
11
P5
9
P6
8
P7
7
10
GND
5
VCC
3
IO
4
POR Circuit
To More Switch Rows
(Up to 4 x 4, 3 x 5 or 2 x 6)
GND
VCC
RST
GND
DS1811
VCC
VCC
1W
RSTZ
The DS1811 has
an internal pull-up
resistor of 5.5 k
Ω
Figure 21. DS2408 AS PARASITE-POWERED PUSH-BUTTON SENSOR
BAT54
0.1U
100k
1
2
3
4
5
6
7
8
9
10
DS2408
P0
2
P1
14
P2
13
P3
12
P4
11
P5
9
P6
8
P7
7
10
GND
5
VCC
3
IO
4
SWITCHES OR PUSH-BUTTONS
Parasite
Power
VCC
1W
GND
RSTZ