MCP4912-E/P Microchip Technology, MCP4912-E/P Datasheet - Page 31

• Manufacturer Part Number: MCP4912-E/P
• Description: DAC 10BIT DUAL W/SPI 14PDIP
• Manufacturer: Microchip Technology

Specifications of MCP4912-E/P

• Number Of Converters: 2
• Settling Time: 4.5µs
• Package / Case: 14-DIP (0.300", 7.62mm)
• Number Of Bits: 10
• Data Interface: Serial, SPI™
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Through Hole
• Number Of Dac Outputs: 2
• Resolution: 10 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: 350 uA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power Dissipation (max): -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

6.6
In some applications, precision digital control of the
output range is desirable.
to use the MCP4902/4912/4922 to achieve this in a
bipolar or single-supply application.
EXAMPLE 6-4:
 2010 Microchip Technology Inc.
Dual Output DAC:
Thevenin
Equivalent
V
V
V
V
IN+
O
OUTB
OUTA
Selectable Gain and Offset Bipolar
Voltage Output Using a Dual DAC
=
=
Offset Adjust Gain Adjust
V
MCP4902
MCP4912
MCP4922
V
----------------------------------------------- -
IN+
=
=
OUTB




V
V
1
REFB
REFA
V
R
+
R
V
IN+
3
R
----- -
R
4
45
+
SPI
2
1
V
BIPOLAR VOLTAGE SOURCE WITH SELECTABLE GAIN AND OFFSET
+
V
G


G
R
REFB
=
=
REFA
V
B
–
4
A

CC-

V
---------------------------------------------- -
Example 6-4
V
V
------------------------------------------- -
D
------ -
D
------ -
2
2
OUTB
OUTA
CC+
N
N
B
A
R
3
3
V
V
R
R
R
DAC
DAC
DD
DD
4
3


4
R
R
----- -
R
+
+
45
+
2
1
R
R


V
+
A
B
Bipolar “Window” DAC using R
5
45
CC-
DAC
DAC
V
illustrates how
45
R
R
5
A
B
3
V
V
OUTA
(Gain Adjust)
OUTB
(Offset Adjust)
D
R
A
V
45
, D
O
R
R
G
1
3
N = DAC Bit Resolution
=
=
B
X
Offset Adjust Gain Adjust
= Digital value of DAC (0-255) for MCP4902
= Digital value of DAC (0-4095) for MCP4922
= Digital value of DAC (0-1023) for MCP4912
------------------
R
V
= Gain selection (1x or 2x)
R
4
IN+
4
+
R
V
V


R
5
1
This circuit is typically used in Multiplier mode and is
ideal for linearizing a sensor whose slope and offset
varies. Refer to Section 6.9 “Using Multiplier Mode”
for more information on Multiplier mode.
The equation to design a bipolar “window” DAC would
be utilized if R
CC
CC
5
+
MCP4902/4912/4922
R
+
R
–
R
----- -
R
4
5
2
1


–
0.1uF
4
V
and R
OUTA
3
, R


5
R
----- -
R
4
2
1


and R
V
V
CC
R
CC
2
+
–
5
are populated.
DS22250A-page 31
V
O