MCP4822-E/SN Microchip Technology, MCP4822-E/SN Datasheet - Page 30

• Manufacturer Part Number: MCP4822-E/SN
• Description: IC DAC 12BIT DUAL W/SPI 8SOIC
• Manufacturer: Microchip Technology

Specifications of MCP4822-E/SN

• Number Of Converters: 2
• Package / Case: 8-SOIC (3.9mm Width)
• Settling Time: 4.5µs
• Number Of Bits: 12
• Data Interface: Serial, SPI™
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Resolution: 12 bit
• Interface Type: Serial (3-Wire, SPI, Microwire)
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 2.7 V
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power Dissipation (max): -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

MCP4802/4812/4822
6.8
Example 6-5
voltage output capable of up to 24-bit resolution from a
dual 12-bit DAC (MCP4822). This design is simply a
voltage divider with a buffered output.
As an example, if an application similar to the one
developed
Design a Bipolar DAC Using Example 6-3 with 12-
bit MCP4822 or MCP4821” required a resolution of
1 µV instead of 1 mV, and a range of 0V to 4.1V, then
12-bit resolution would not be adequate.
EXAMPLE 6-5:
DS22249A-page 30
SPI
Designing a Double-Precision
DAC Using a Dual DAC
V
V
OUTA
OUTB
in
illustrates how to design a single-supply
V
3-wire
MCP4822
MCP4822
O
V
V
Section 6.6.1
=
=
DD
DD
=
2.048 G
2.048 G
V
----------------------------------------------------- -
OUTA
SIMPLE, DOUBLE-PRECISION DAC WITH MCP4822


R
R
(DAC
(DAC
2
1
V
A
B
V
+
+
OUTB


OUTA
-------
2
D
D
-------
2
V
R
12
“Design
12
A
B
OUTB
2
B
A
for Course Adjustment)
for Fine Adjustment)
R
1
Example:
R
1
>> R
2
R
R
2
Step 1: Calculate the resolution needed:
Step 2: Since DAC
Step 3: If R
Step 4: The resulting transfer function is shown in the
1
G
D
n
x
0.1 µF
22-bit
DNL = ±0.75 LSb, this design can be done
with the 12-bit MCP4822 DAC.
its output only needs to be “pulled” 1/1000 to
meet the 1 µV target. Dividing V
would allow the application to compensate for
DAC
equation of
4.1V/1 µV = 4.1 x 10
= Gain selection (1x or 2x)
= Digital value of DAC (0-4096)
2
B
is 100, then R
’s DNL error.
resolution
V
V
B
Example
CC
’s V
CC
+
–
 2010 Microchip Technology Inc.
OUTB
6
1
6-5.
has a resolution of 1 mV,
. Since 2
needs to be 100 k.
is
desired.
22
OUTA
V
= 4.2 x 10
O
by 1000
Since
6
,