MCP3422 Microchip Technology Inc., MCP3422 Datasheet - Page 12

• Manufacturer Part Number: MCP3422
• Description: 18-bit, Multi-channel ?? Analog-to-digital Converter With I2c? Interface And On-board Reference
• Manufacturer: Microchip Technology Inc.

MCP3422/3/4
FIGURE 3-1:
3.3
SCL is the serial clock pin of the I
device act only as a slave and the SCL pin accepts
only external serial clocks. The input data from the
Master device is shifted into the SDA pin on the rising
edges of the SCL clock and output from the slave
device occurs at the falling edges of the SCL clock.
The SCL pin is an open-drain N-channel driver.
Therefore, it needs a pull-up resistor from the V
to the SCL pin. Refer to Section 5.3 “I
munications” for more details of I
communication.
DS22088B-page 12
Serial Clock Pin (SCL)
V
L
EGEND
R
SS
CHn
C
R
PIN
V
ss
V
T
CHn
Equivalent Analog Input Circuit.
=
=
=
=
=
Signal Source
Source Impedance
Analog Input Pin
Input Pin Capacitance
Threshold Voltage
4 pF
C
2
PIN
2
C Serial Interface
C interface. The
2
C Serial Com-
D
D
1
2
V
DD
DD
V
V
T
T
line
= 0.6V
= 0.6V
V
D1, D2
SS
C
I
LEAKAGE
SAMPLE
3.4
SDA is the serial data pin of the I
pin is used for input and output data. In read mode, the
conversion result is read from the SDA pin (output). In
write mode, the device configuration bits are written
(input) though the SDA pin. The SDA pin is an
open-drain N-channel driver. Therefore, it needs a
pull-up resistor from the V
Except for start and stop conditions, the data on the
SDA pin must be stable during the high period of the
clock. The high or low state of the SDA pin can only
change when the clock signal on the SCL pin is low.
Refer to Section 5.3 “I
for more details of I
Typical range of the pull-up resistor value for SCL and
SDA is from 5 kΩ to 10 kΩ for standard (100 kHz) and
fast (400 kHz) modes, and less than 1 kΩ for high
speed mode (3.4 MHz).
3.5
There is an internal electrical connection between the
Exposed Thermal Pad (EP) and the V
be connected to the same potential on the Printed
Circuit Board (PCB).
I
(~ ±1 nA)
SS
LEAKAGE
R
s
=
=
=
=
=
Exposed Thermal Pad (EP)
Serial Data Pin (SDA)
Leakage Current at Analog Pin
Sampling Switch
Sampling Switch Resistor
Sample Capacitance
ESD Protection Diode
SS
2
Sampling
Switch
C Serial Interface communication.
© 2008 Microchip Technology Inc.
2
C Serial Communications”
R
S
DD
2
line to the SDA pin.
C interface. The SDA
C
(3.2 pF)
SS
SAMPLE
pin; they must