MCP4901-E/P Microchip Technology, MCP4901-E/P Datasheet - Page 32

• Manufacturer Part Number: MCP4901-E/P
• Description: DAC 8BIT SGL W/SPI 8PDIP
• Manufacturer: Microchip Technology

Specifications of MCP4901-E/P

• Number Of Converters: 1
• Settling Time: 4.5µs
• Package / Case: 8-DIP (0.300", 7.62mm)
• Number Of Bits: 8
• Data Interface: Serial, SPI™
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Through Hole
• Number Of Dac Outputs: 1
• Resolution: 8 bit
• Interface Type: SPI
• Supply Voltage (max): 6.5 V
• Supply Voltage (min): 2.7 V
• Maximum Operating Temperature: + 125 C
• Mounting Style: Through Hole
• Minimum Operating Temperature: - 55 C
• Supply Current: 175 uA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power Dissipation (max): -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

MCP4901/4911/4921
6.7
Example 6-5
voltage output capable of up to 24-bit resolution by
using 12-bit DACs. This design is simply a voltage
divider with a buffered output.
As an example, if a similar application to the one
developed
Design a bipolar dac using example 6-3 with 12-bit
MCP4912 or MCP4922” 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:
DS22248A-page 32
Designing a Double-Precision
DAC
V
SPI
REF
in Section 6.5.1
illustrates how to design a single-supply
V
V
V
3
OUTA
O
OUTB
V
V
DAC
DAC
DD
DD
=
SIMPLE, DOUBLE PRECISION DAC WITH MCP4921 OR MCP4922.
V
-----------------------------------------------------
=
=
OUTA
A
B
V
V
REFA
REFB
DAC
DAC
R
R
2
1
+
+
G
G
“Design
B
A
V
V
R
R
A
B
V
(Course Adjust)
OUTA
OUTB
2
(Fine Adjust)
D
-------
2
D
-------
2
1
OUTB
12
12
>> R
A
B
R
1
2
Example:
R
R
2
1
0.1 µF
1.
2.
3.
4.
Calculate the resolution needed:
4.1V/1 µV = 4.1x 10
22-bit resolution is desired. Since DNL = ±0.75
LSB, this design can be done with the MCP4921
or MCP4922.
Since the DAC
1 mV, 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
If R
The resulting transfer function is not perfectly
linear, as shown in the equation of
2
B
V
V
is 100, then R
’s DNL error.
G = Gain selection (1x or 2x)
D = Digital value of DAC (0-4096)
CC
CC
+
–
B
‘s V
 2010 Microchip Technology Inc.
1
6
OUTB
. Since 2
needs to be 100 k.
V
O
has a resolution of
22
OUTA
Example
= 4.2 x 10
by 1000
6-5.
6
,