MCP4728 Microchip Technology Inc., MCP4728 Datasheet - Page 21

• Manufacturer Part Number: MCP4728
• Description: 12-bit, Quad Digital-to-analog Converter With Eeprom Memory
• Manufacturer: Microchip Technology Inc.

3.0
The descriptions of the pins are listed in
TABLE 3-1:
3.1
The device has four analog voltage output (V
Each output is driven by its own output buffer with a
gain of 1 or 2 depending on the gain and V
bit settings. In normal mode, the DC impedance of the
output pin is about 1Ω. In Power-Down mode, the
output pin is internally connected to 1 kΩ, 100 kΩ, or
500 kΩ, depending on the Power-Down selection bit
settings.
The V
load. It is recommended to use a load with R
than 5 kΩ.
© 2009 Microchip Technology Inc.
Legend: P = Power, OI = Open-Drain Input, OO = Open-Drain Output, ST = Schmitt Trigger Input Buffer,
Note 1:
Pin No.
10
1
2
3
4
5
6
7
8
9
OUT
2:
PIN DESCRIPTIONS
Analog Output Voltage Pins (V
V
AO = Analog Output
OUT
RDY/BSY
pin can drive up to 1000 pF of capacitive
This pin needs an external pull-up resistor from V
This pin can be driven by MCU.
V
V
V
V
Name
LDAC
SDA
OUT
OUT
SCL
OUT
OUT
V
V
B,
DD
SS
V
PIN FUNCTION TABLE
C
D
A
B
OUT
C,
Pin Type
OI/OO
V
OO
AO
AO
AO
AO
ST
OI
P
P
OUT
D
)
Supply Voltage
I
I
This pin is used for two purposes:
(a) Synchronization Input. It is used to transfer the contents of the DAC input
registers to the output registers (V
(b) Select the device for reading and writing I
This pin is a status indicator of EEPROM programming activity. An external pull-up
resistor (about 100 kΩ) is needed from RDY/BSY pin to V
Buffered analog voltage output of channel A. The output amplifier has rail-to-rail
operation.
Buffered analog voltage output of channel B. The output amplifier has rail-to-rail
operation.
Buffered analog voltage output of channel C. The output amplifier has rail-to-rail
operation.
Buffered analog voltage output of channel D. The output amplifier has rail-to-rail
operation.
Ground reference.
2
2
C Serial Clock Input. (Note 1)
C Serial Data Input and Output. (Note 1)
Table
REF
OUT
selection
L
3-1.
greater
) pins.
OUT
A,
DD
3.2
V
at the V
as the DAC external reference. The power supply at
the V
DAC performance.
It is recommended to use an appropriate bypass
capacitor of about 0.1 µF (ceramic) to ground. An
additional 10 µF capacitor (tantalum) in parallel is also
recommended to further attenuate high frequency
noise present in application boards. The supply voltage
(V
specified operation.
V
device. The user must connect the V
plane through a low impedance connection. If an
analog ground path is available in the application PCB
(printed circuit board), it is highly recommended that
the V
isolated within an analog ground plane of the circuit
board.
line.
DD
SS
DD
OUT
is the ground pin and the current return path of the
is the power supply pin for the device. The voltage
) must be maintained in the 2.7V to 5.5V range for
DD
SS
Function
DD
).
pin should be as clean as possible for a good
Supply Voltage Pins (V
pin be tied to the analog ground path or
pin is used as the power supply input as well
2
C address bits. (Note 2)
DD
MCP4728
line. (Note 1)
SS
DS22187A-page 21
DD
pin to a ground
, V
SS
)