MCP3424EV Microchip Technology, MCP3424EV Datasheet - Page 27

• Manufacturer Part Number: MCP3424EV
• Description: EVALUATION BOARD FOR MCP3424
• Manufacturer: Microchip Technology

Specifications of MCP3424EV

• Number Of Adc's: 1
• Number Of Bits: 18
• Sampling Rate (per Second): 3.75 ~ 240
• Data Interface: I²C
• Inputs Per Adc: 4 Differential
• Input Range: ±2.048 V
• Power (typ) @ Conditions: 135µA @ 240sps
• Voltage Supply Source: Single Supply
• Operating Temperature: -55°C ~ 125°C
• Utilized Ic / Part: MCP3424
• Processor To Be Evaluated: MCP3424
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

6.0
The MCP3424 device can be used for various precision
analog-to-digital converter applications. The device
operates with very simple connections to the
application circuit. The following sections discuss the
examples of the device connections and applications.
6.1
6.1.1
For an accurate measurement, the application circuit
needs a clean supply voltage and must block any noise
signal to the MCP3424 device.
example of using two bypass capacitors (a 10 µF
tantalum capacitor and a 0.1 µF ceramic capacitor) on
the V
any high frequency noises on the V
provide the momentary bursts of extra currents when
the device needs from the supply. These capacitors
should be placed as close to the V
(within one inch). If the application circuit has separate
digital and analog power supplies, the V
the MCP3424 device should reside on the analog
plane.
6.1.2
The SCL and SDA pins of the MCP3424 are open-drain
configurations. These pins require a pull-up resistor as
shown in
resistors depends on the operating speed (standard,
fast, and high speed) and loading capacitance of the
I
less power, but increases the signal transition time
(higher RC time constant) on the bus. Therefore, it can
limit the bus operating speed. The lower value of
resistor, on the other hand, consumes higher power,
but allows higher operating speed. If the bus line has
higher capacitance due to long bus line or high number
of devices connected to the bus, a smaller pull-up
resistor is needed to compensate the long RC time
constant. The pull-up resistor is typically chosen
between 5 kΩ and 10 kΩ ranges for standard and fast
modes, and less than 1 kΩ for high speed mode
depending on the presence of bus loading capacitance.
© 2008 Microchip Technology Inc.
2
C bus line. Higher value of pull-up resistor consumes
DD
line. These capacitors are helpful to filter out
BASIC APPLICATION
CONFIGURATION
Connecting to the Application
Circuits
Figure
BYPASS CAPACITORS ON V
CONNECTING TO I
PULL-UP RESISTORS
6-1. The value of these pull-up
Figure 6-1
2
C BUS USING
DD
DD
pin as possible
DD
line and also
and V
shows an
DD
PIN
SS
of
6.1.3
The user can tie the Adr0 and Adr1 pins to V
or left floating. See more details in Section 5.3.2
“Device Address Bits (A2, A1, A2) and Address
Selection Pins.”
FIGURE 6-1:
Figure 6-2
nections. The I
as the number of device connected to the I
increases. The bus loading capacitance affects on the
bus operating speed. For example, the highest bus
operating speed for the 400 pF bus capacitance is
1.7 MHz, and 3.4 MHz for 100 pF. Therefore, the user
needs to consider the releationship between the maxi-
mum operation speed versus. the number of I
devices that are connected to the I
FIGURE 6-2:
Connection on I
Signal 1
Input
Signal 2
Input
Rp is the pull-up resistor:
C1: 0.1 µF, Ceramic capacitor
C2: 10 µF, Tantalum capacitor
5 kΩ - 10 kΩ for f
Microcontroller
(PIC16F876)
C
C
1
~700Ω for f
2
shows an example of multiple device con-
I
MCP3424
2
C ADDRESS SELECTION PINS
2
C bus loading capacitance increases
2
4
5
6
2
7
1
3
R
C Bus.
P
CH1+
CH1-
CH2+
V
SDA
CH2-
V
SCL
SCL
SS
DD
MCP3424
Typical Connection.
Example of Multiple Device
SDA SCL
=
=
CH3+
CH4+
MCP3424
CH4-
CH3-
100 kHz to 400 kHz
3.45 MHz
Adr1
Adr0
SCL
2
14
13
12
11
10
9
8
R
C bus line.
EEPROM
(24LC01)
MCP4725
P
DS22088A-page 27
(MASTER)
2
I
Selection
Pins
T
2
C bus line
Input
Signal 4
Signal 3
C Address
O
Input
SS
MCU
V
DD
, V
DD
2
C
,