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© 2006 Microchip Technology Inc. DS21732C-page 1
MCP3221
Features
• 12-bit resolution
• ±1 LSB DNL, ±2 LSB INL max.
• 250 µA max conversion current
• 5 nA typical standby current, 1 µA max.
•I
2
C™-compatible serial interface
- 100 kHz I
2
C Standard Mode
- 400 kHz I
2
C Fast Mode
• Up to 8 devices on a single 2-Wire bus
• 22.3 ksps in I
2
C Fast Mode
• Single-ended analog input channel
• On-chip sample and hold
• On-chip conversion clock
• Single-supply specified operation: 2.7V to 5.5V
• Temperature range:
- Industrial: -40°C to +85°C
- Extended: -40°C to +125°C
• Small SOT-23-5 package
Applications
• Data Logging
• Multi-zone Monitoring
• Hand-Held Portable Applications
• Battery-Powered Test Equipment
• Remote or Isolated Data Acquisition
Package Type
Description
The Microchip Technology Inc. MCP3221 is a
successive approximation A/D converter with 12-bit
resolution. Available in the SOT-23-5 package, this
device provides one single-ended input with very low
power consumption. Based on an advanced CMOS
technology, the MCP3221 provides a low maximum
conversion current and standby current of 250 µA and
1 µA, respectively. Low current consumption,
combined with the small SOT-23 package, make this
device ideal for battery-powered and remote data
acquisition applications.
Communication to the MCP3221 is performed using a
2-wire, I
2
C compatible interface. Standard (100 kHz)
and Fast (400 kHz) I
2
C modes are available with the
device. An on-chip conversion clock enables
independent timing for the I
2
C and conversion clocks.
The device is also addressable, allowing up to eight
devices on a single 2-wire bus.
The MCP3221 runs on a single supply voltage that
operates over a broad range of 2.7V to 5.5V. This
device also provides excellent linearity of ±1 LSB
differential non-linearity and ±2 LSB integral non-lin-
earity, maximum.
Functional Block Diagram
5-Pin SOT-23
SCL
A
IN
MCP3221
1
2
3
5
SDA
V
SS
V
DD
4
Comparator
Sample
and
Hold
12-bit SAR
DAC
I
2
C™ Interface
A
IN
V
SS
V
DD
SCL SDA
Clock
Control Logic
–
+
Low Power 12-Bit A/D Converter With I
2
C™ Interface
