MCP4912-E/ST Microchip Technology, MCP4912-E/ST Datasheet - Page 34

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

Specifications of MCP4912-E/ST

• Number Of Converters: 2
• Settling Time: 4.5µs
• Package / Case: 14-TSSOP
• Number Of Bits: 10
• Data Interface: Serial, SPI™
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• 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: SMD/SMT
• 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

MCP4902/4912/4922
6.9
The MCP4902/4912/4922 family of devices use exter-
nal reference, and these devices are ideally suited for
use as a multiplier/divider in a signal chain. The
common applications are: (a) Precision programmable
gain/attenuator amplifiers and (b) Motor control
feedback loop. The wide input range (0V – V
Unbuffered mode and near rail-to-rail range in Buffered
mode: its bandwidth (> 400 kHz), selectable 1x/2x gain
and low power consumption give maximum flexibility to
meet the application’s needs.
To configure the MCP4902/4912/4922 family of
devices for multiple applications, connect the input sig-
nal to V
fer, gain and output value. The DAC’s output can utilize
any of Examples 6-1 to 6-6, depending on the applica-
tion requirements.
the DAC can operate in a motor control feedback loop.
EXAMPLE 6-7:
DS22250A-page 34
REF
Using Multiplier Mode
and serially configure the DAC’s input buf-
(b) Dual Output DAC:
(a) Single Output DAC:
Example 6-7
MULTIPLIER MODE USING V
is an illustration of how
MCP4912
MCP4922
MCP4902
MCP4901
MCP4911
MCP4921
DD
V
REF
) is in
SPI
V OUT
REF
3
=
V
DAC
V
DD
INPUT
REF
If the gain selection bit is configured for 1x mode
(<GA> = 1), the resulting input signal will be attenuated
by D/2
if the gain is configured for 2x mode (<GA> = 0), the
codes less than 2048 attenuate the signal, while the
codes greater than 2048 gain the signal.
A DAC provides significantly more gain/attenuation
resolution when compared to typical Programmable
Gain Amplifiers. Adding an op amp to buffer the output,
as illustrated in Examples 6-2 to 6-6, extends the
output range and power to meet the precise needs of
the application.

G

Z
n
V
D
------
2
FB
. With the 12-bit DAC (MCP4921 or MCP4922),
OUT
N
n
V
V
RPM_SET
RPM
V
V
CC
 2010 Microchip Technology Inc.
CC
+
–
+
-
R
sense