MCP4821-E/SN Microchip Technology, MCP4821-E/SN Datasheet - Page 31
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MCP4821-E/SN
Manufacturer Part Number
MCP4821-E/SN
Description
IC DAC 12BIT W/SPI 8SOIC
Manufacturer
Microchip Technology
Specifications of MCP4821-E/SN
Number Of Converters
1
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
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
MCP4821-E/SN
Manufacturer:
SAMSUNG
Quantity:
3 440
Part Number:
MCP4821-E/SN
Manufacturer:
MICROCHIP/微芯
Quantity:
20 000
6.9
Example 6-6
programmable current source using a voltage follower.
The current sensor (sensor resistor) is used to convert
the DAC voltage output into a digitally-selectable
current source.
Adding the resistor network from
be advantageous in this application. The smaller
R
EXAMPLE 6-6:
2010 Microchip Technology Inc.
SENSE
I
where
I
L
b
=
=
-------------- -
R
V
Building Programmable Current
Source
is, the less power dissipated across it.
I
----
(a) Single Output DAC:
(b) Dual Output DAC:
L
sense
OUT
Common-Emitter Current Gain
shows an example of building a
------------ -
+
1
DIGITALLY-CONTROLLED CURRENT SOURCE
MCP4801
MCP4811
MCP4821
MCP4802
MCP4812
MCP4822
Example 6-2
SPI
would
3-wire
V
DAC
DD
D
G
N
n
=
=
=
=
=
Gain selection (1x or 2x)
Digital value of DAC (0-255) for MCP4801/MCP4802
Digital value of DAC (0-1023) for MCP4811/MCP4812
Digital value of DAC (0-4095) for MCP4821/MCP4822
DAC bit resolution
However, this also reduces the resolution that the
current can be controlled with. The voltage divider, or
“window”, DAC configuration would allow the range to
be reduced, thus increasing resolution around the
range of interest. When working with very small sensor
voltages, plan on eliminating the amplifier’s offset error
by storing the DAC’s setting under known sensor
conditions.
V
OUT
MCP4801/4811/4821
V
V
CC
CC
–
+
R
I
SENSE
b
V
DD
Load
or V
REF
I
L
DS22244B-page 31