MCP4706A3T-E/CH Microchip Technology, MCP4706A3T-E/CH Datasheet - Page 36

• Manufacturer Part Number: MCP4706A3T-E/CH
• Description: Single, 8-bit NV DAC With Ext Vref And I2C Interface 6 SOT-23 T/R
• Manufacturer: Microchip Technology
• Series: -r

Specifications of MCP4706A3T-E/CH

• Number Of Converters: 1
• Conversion Rate: 1
• Resolution: 8 bit
• Interface Type: I2C
• Settling Time: 6 us
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 2.7 V
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Package / Case: SOT-23-6
• Maximum Power Dissipation: 452 mW
• Minimum Operating Temperature: - 40 C
• Supply Current: 210 uA
• Number Of Bits: 8
• Data Interface: EEPROM, I²C, Serial
• Voltage Supply Source: Single Supply
• Power Dissipation (max): 452mW
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Number Of Outputs And Type: *
• Lead Free Status / Rohs Status: Details

MCP4706/4716/4726
4.2
The device can be configured to use one of three
voltage sources for the resistor ladder’s reference
voltage (V
1.
2.
3.
The selection of the voltage is specified with the volatile
V
are nonvolatile and volatile V
bits. On a POR/BOR event, the state of the nonvolatile
V
volatile V
When the user selects the V
pin voltage is not connected to the resistor ladder.
If the V
between the buffered or unbuffered mode.
In unbuffered mode, the V
V
In buffered mode, the V
0.01V to V
provides low offset voltage, low noise, and a very high
input impedance, with only minor limitations on the
input range and frequency response.
FIGURE 4-2:
Voltage Selection Block Diagram.
DS22272A-page 36
REF1
REF1
SS
Note:
Note:
V
V
V
to V
DD
REF
REF
:V
:V
REF
REF0
REF0
DD
DAC’s (Resistor Ladder)
Reference Voltage
pin voltage
REF1
RL
pin voltage internally buffered
pin voltage unbuffered
V
.
In unbuffered mode, the voltage source
should have a low output impedance. If
the voltage source has a high output
impedance, then the voltage on the
V
The
impedance of 210 kΩ and a typical
capacitance of 29 pF.
Any variation or noises on the reference
source can directly affect the DAC output.
The reference voltage needs to be as
clean as possible for accurate DAC
performance.
pin is selected, then one needs to select
) (see
REF
DD
REF
configuration bits (see
:V
configuration bits are latched into the
-0.04V. The input buffer (amplifier)
REF0
’s pin would be lower than expected.
resistor
Buffer
Figure
V
DD
configuration bits.
Resistor Ladder Reference
REF
4-2). These are:
REF
V
REF1
ladder
DD
pin voltage may be from
REF1
pin voltage may be from
as reference, the V
:V
:V
REF0
REF0
Table
has
V
RL
configuration
4-4). There
a
typical
REF
4.3
The resistor ladder is a digital potentiometer with the B
Terminal internally grounded and the A terminal
connected to the selected reference voltage (see
Figure
wiper position. The wiper voltage (V
the DAC register value divided by the number of
resistor elements (R
4096) related to the V
The resistor ladder (R
approximately 210 kΩ. This resistor ladder resistance
(R
Since this is a voltage divider configuration, the actual
R
voltage at V
If the unbuffered V
source, this voltage source should have a low output
impedance.
When the DAC is powered down, the resistor ladder is
disconnected from the selected reference voltage.
FIGURE 4-3:
Where:
RL
R
V
Note:
RL
# Resistors in Resistor Ladder = 256 (MCP4706)
W
RL
resistance does not effect the output given a fixed
) may vary from device to device up to ±20%.
=
PD1:PD0
4-3). The volatile DAC register controls the
R
R
R
R
S(2
S(2
S(2
S(1)
Resistor Ladder
# Resistors in Resistor Ladder
n
n
n
The maximum wiper position is 2
while the number of resistors in the
resistor ladder is 2
when the DAC register is at full scale,
there is one resistor element (R
between the wiper and the V
RL
)
- 1)
- 2)
.
DAC Register Value
REF
V
S
RL
RL
) in the ladder (256, 1024, or
RL
Resistor Ladder.
pin is used as the V
© 2011 Microchip Technology Inc.
voltage.
) has a typical impedance of
2
2
n
n
1
0
- 1
- 2
n
Register
. This means that
DAC
W
1024 (MCP4716)
4096 (MCP4726)
) is proportional to
RL
* V
voltage.
RL
RL
V
voltage
n
W
- 1,
S
)