MCP4728-E/UN Microchip Technology, MCP4728-E/UN Datasheet - Page 26

• Manufacturer Part Number: MCP4728-E/UN
• Description: IC DAC 12BIT W/I2C 10-MSOP
• Manufacturer: Microchip Technology

Specifications of MCP4728-E/UN

• Number Of Converters: 4
• Settling Time: 6µs
• Package / Case: 10-MSOP, Micro10™, 10-uMAX, 10-uSOP
• Number Of Bits: 12
• Data Interface: I²C
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Number Of Dac Outputs: 4
• Resolution: 12 bit
• Interface Type: I2C
• 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
• Supply Current: 110 mA
• Voltage Reference: 2.048 V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: MCP4728EV - BOARD EVAL 12BIT 4CH DAC MCP4728
• Power Dissipation (max): -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

MCP4728
4.5
The device has a precision internal voltage reference
which provides a nominal voltage of 2.048V. The user
can select the internal voltage reference or V
voltage reference source of each channel using the
V
circuit is turned off when all channels select V
their references. However, it stays turned on if any one
of the channels selects the internal reference.
4.6
The LSB is defined as the ideal voltage difference
between two successive codes. LSB sizes of the
MCP4728 device are shown in
TABLE 4-4:
4.7
Each channel has an independent output associated
with its own configuration bit settings and DAC input
code. When the internal voltage reference is selected
(V
to the resistor string DAC of the channel. When the
external reference (V
for the channel’s resistor string DAC.
The V
DAC performance. When the V
voltage reference, any variation or noises on the V
line can directly affect on the DAC output.
The
programmable gain block. The rail-to-rail output
amplifier has a configurable gain of 1 or 2. But the gain
of 2 is not applicable if V
reference. The formula for the analog output voltage is
given in
4.7.1
The DAC output voltage range varies depending on the
voltage reference selection.
• When the internal reference (V
DS22187E-page 26
Note 1:
REF
(2.048V)
REF
selected:
- V
- V
Internal
V
V
V
Gain of 1
Gain of 2
REF
REF
DD
configuration bit. The internal voltage reference
DD
OUT
OUT
analog
= internal), it supplies the internal V
Equation 4-1
Voltage Reference
LSB Size
DAC Output Voltage
needs to be as clean as possible for accurate
= 0.000V to 2.048V * 4095/4096 for
= 0.000V to 4.096V * 4095/4096 for
LSB size varies with the V
When V
G
ignored.
OUTPUT VOLTAGE RANGE
X
Gain (G
Selection
= 1 by default. G
output
x1
x2
x1
LSB SIZES (EXAMPLE)
REF
REF
X
and
)
= V
=V
of
DD
Equation
V
LSB Size
DD
DD
0.5 mV
DD
is selected for the voltage
1 mV
each
, the device uses
) is selected, V
/4096
Table
X
DD
REF
= 2 option is
4-2.
is selected as the
channel
=2.048V) is
4-4.
DD
2.048V/4096
4.096V/4096
Condition
range.
(Note
REF
DD
DD
has
voltage
is used
1)
as the
DD
DD
as
a
• When the external reference (V
EQUATION 4-1:
EQUATION 4-2:
4.8
The following events update the output registers
(V
a.
b.
c.
d.
4.8.1
The user can use the LDAC pin or UDAC bit to upload
the input DAC register to output DAC register (V
However, the UDAC affects only the selected channel
while the LDAC affects all channels. The UDAC bit is
not used in the Fast Mode Writing.
Table 4-5
UDAC bit conditions.
Where:
Where:
V
selected:
- V
Note:
OUT
REF
G
D
D
LDAC pin to “Low”: Updates all DAC channels.
UDAC bit to “Low”: Updates a selected channel
only.
General Call Software Update Command:
Updates all DAC channels.
Power-on
command: Both input and output registers are
updated with EEPROM data. All channels are
affected.
n
x
n
OUT
):
Output Voltage Update
=
=
=
=
shows the output update vs. LDAC pin and
= 0.000V to V
V
The gain selection bit is not applicable
for V
is used regardless of the gain selection
bit setting.
LDAC PIN AND UDAC BIT
OUT =
2.048V for internal reference selection
DAC input code
Gain Setting
DAC input code
REF
Reset
V
OUT
(V
= V
REF x
V
INTERNAL REFERENCE
V
4096
© 2010 Microchip Technology Inc.
DD
OUT
OUT
=
DD
or
(
---------------------------- -
. In this case, Gain of 1
D
V
n
FOR
FOR
DD
General
)
4096
×
x
REF
D
V
V
G
n
REF
REF
x
)
=V
≤
Call
DD
=
=
V
DD
) is
V
DD
Reset
OUT
).