MCP3426/7/8
16-Bit, Multi-Channel Analog-to-Digital Converter with
2
I C Interface and On-Board Reference
Features Description
16-bit ADC with Differential Inputs: The MCP3426, MCP3427 and MCP3428 devices
(MCP3426/7/8) are the low noise and high accuracy
- 2 channels: MCP3426 and MCP3427
16Bit Delta-Sigma Analog-to-Digital ( A/D) Con-
- 4 channels: MCP3428
verter family members of the MCP342X series from
Differential Input Full Scale Range: -V to
REF
Microchip Technology Inc. These devices can convert
+V
REF
analog inputs to digital codes with up to 16 bits of reso-
Self Calibration of Internal Offset and Gain per
lution.
Each Conversion
The MCP3426 and MCP3427 devices have two
On-Board Voltage Reference (V ):
REF
differential input channels and the MCP3428 has four
- Accuracy: 2.048V 0.05%
differential input channels. All electrical properties of
- Drift: 15 ppm/C
these three devices are the same except the
2
differences in the number of input channels and I C
On-Board Programmable Gain Amplifier (PGA):
address bit selection options.
- Gains of 1,2, 4 or 8
These devices can output analog-to-digital conversion
INL: 10 ppm of Full Scale Range
results at rates of 15 (16-bit mode), 60 (14-bit mode), or
Programmable Data Rate Options:
240 (12-bit mode) samples per second depending on
- 15 SPS (16 bits)
the user controllable configuration bit settings using the
- 60 SPS (14 bits) 2
two-wire I C serial interface. During each conversion,
- 240 SPS (12 bits)
the device calibrates offset and gain errors
One-Shot or Continuous Conversion Options automatically. This provides accurate conversion
results from conversion to conversion over variations in
Low Current Consumption (V = 3V):
DD
temperature and power supply fluctuation.
- Continuous Conversion: 135 A typical
The device has an on-board 2.048V reference voltage,
- One-Shot Conversion with 1 SPS:
which enables an input range of 2.048V differentially
- 9 A typical for 16 bit mode
(full scale range = 4.096/PGA).
- 2.25 A typical for 14 bit mode
- 0.56 A typical for 12 bit mode
The user can select the gain of the on-board
On-Board Oscillator programmable gain amplifier (PGA) using the
2
configuration register bits (gain of x1, x2, x4, or x8).
I C Interface:
This allows the MCP3426/7/8 devices to convert a very
- Standard, Fast and High Speed Modes
weak input signal with high resolution.
- User configurable two external address
The MCP3426/7/8 devices have two conversion
selection pins for MCP3427 and MCP3428
modes: (a) One-Shot Conversion mode and
Single Supply Operation: 2.7V to 5.5V
(b)Continuous Conversion mode. In the One-Shot
Extended Temperature Range: -40C to +125C
conversion mode, the device performs a single
conversion and enters a low current standby
Typical Applications
(shutdown) mode automatically until it receives another
conversion command. This reduces current
Portable Instrumentation and Consumer Goods
consumption greatly during idle periods. In continuous
Temperature Sensing with RTD, Thermistor, and
conversion mode, the conversion takes place
Thermocouple
continuously at the configured conversion speed. The
Bridge Sensing for Pressure, Strain, and Force
device updates its output buffer with the most recent
Weigh Scales and Battery Fuel Gauges
conversion data.
Factory Automation Equipment
The devices operate from a single 2.7V to 5.5V power
2
supply and have a two-wire I C compatible serial
interface for a standard (100 kHz), fast (400 kHz), or
high-speed (3.4 MHz) mode.
2009 Microchip Technology Inc. DS22226A-page 1MCP3428
MCP3427
MCP3426
MCP3426/7/8
2
The I C address bits for the MCP3427 and MCP3428
The MCP3426 is available in 8-pin SOIC, DFN, and
2
are selected by using two external I C address MSOP packages. The MCP3427 is available in 10-pin
selection pins (Adr0 and Adr1). The user can configure DFN, and MSOP packages. The MCP3428 is available
the device to one of eight available addresses by in 14-pin SOIC and TSSOP packages.
connecting these two address selection pins to V ,
DD
2
V or float. The I C address bits of the MCP3426 are
SS
programmed at the factory during production.
Package Types
MSOP, SOIC MSOP SOIC, TSSOP
CH1+ CH1+ 1 14
10 Adr1 CH4-
1
CH1+
8
1 CH2-
CH1- 2 9 CH1- 2 13
Adr0
CH4+
CH1-
7
2 CH2+
V 3 8 SCL
12
SS 3
V CH2+ CH3-
3 6 V
DD
SS
CH2+ 4
7 SDA
4 5 SCL 4 11
SDA CH2-
CH3+
V
CH2- 5 6
DD
5
V 10
Adr1
SS
6
9
V Adr0
DD
7 8
SDA SCL
MCP3426 MCP3427
2x3 DFN * 3x3 DFN *
CH1+ CH2- CH1+ Adr1
1 8 1 10
CH1- CH2+ CH1- Adr0
2 7 2 9
EP
EP
9
V V V SCL
3 6 3 8
DD SS SS 11
SDA 4 5 SCL CH2+ 4 7 SDA
CH2- 5 6 V
DD
* Includes Exposed Thermal Pad (EP); see Table 3-1.
MCP3426 Functional Block Diagram
V
V
DD
SS
Voltage Reference
MCP3426
(2.048V)
V
REF
CH1+
SCL
2
I C
ADC
CH1-
PGA
Converter SDA
Interface
CH2+
Gain = 1, 2, 4, or 8
CH2-
Clock
Oscillator
DS22226A-page 2 2009 Microchip Technology Inc.
MUX