Datasheet

MAX7367/MAX7368/MAX7369
4-Channel I
2
C Switches/Multiplexer
16 ______________________________________________________________________________________
20
19
18
17
16
15
14
1
2
3
4
5
6
7
V
DD
SDA
SCL
INTINT0
A2
A1
A0
TOP VIEW
MAX7369
SC3
SD3
INT3INT1
SC0
138 SC2SD1
129 SD2SC1
1110 INT2GND
SD0
TSSOP
+
16
15
14
13
12
11
10
1
2
3
4
5
6
7
V
DD
SDA
SCL
A2SD0
RESET
A1
A0
MAX7368
SC3
SD3
SC2SC1
SD1
98 SD2GND
SC0
TSSOP
+
Pin Configurations (continued)
Choosing Pullup Resistors
I
2
C requires pullup resistors to provide a logic-high
level to data and clock lines. There are tradeoffs
between power dissipation and speed, and a compro-
mise must be made in choosing pullup resistor values.
Every device connected to the bus introduces some
capacitance even when the device is not in operation.
I
2
C specifies 300ns rise times to go from low to high
(30% to 70%) for fast mode, which is defined for a data
rate of 400kbps (refer to I
2
C specifications for details).
In order to meet the rise time requirement, choose the
pullup resistors such that the rise time (t
R
=
0.85R
PULLUP
xC
BUS
) is less than 300ns. For a bus
capacitance of 400pF, choose a pullup resistor less
than 880Ω. Often I
2
C devices work when the maximum
specified rise time is exceeded. However, if the rise
times become too slow, the devices on the bus do not
recognize the command signals. Optional resistors (24Ω)
in series with SDA and SCL protect the device inputs
from high-voltage spikes on the bus lines and also mini-
mize crosstalk and undershoot of the bus signals.
Chip Information
PROCESS: BiCMOS