MCP4725A0T-E/CH Microchip Technology, MCP4725A0T-E/CH Datasheet - Page 23

• Manufacturer Part Number: MCP4725A0T-E/CH
• Description: IC DAC 12BIT W/I2C SOT23A-6
• Manufacturer: Microchip Technology

Specifications of MCP4725A0T-E/CH

• Number Of Converters: 1
• Package / Case: SOT-23-6
• Settling Time: 6µs
• Number Of Bits: 12
• Data Interface: I²C, Serial
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Resolution: 12 bit
• Interface Type: Serial (2-Wire, 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
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: MCP4725DM-PTPLS - BOARD DAUGHTER PICTAIL MCP4725
• Power Dissipation (max): -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: MCP4725A0T-E/CHTR; MCP4725AOT-E/CHTR; MCP4725AOT-E/CHTR

6.0
When the device is connected to the I
device is working as a slave device. The Master (MCU)
can write/read the DAC input register or EEPROM
using the I
device address contains four fixed bits ( 1100 = device
code) and three address bits (A2, A1, A0). The A2 and
A1 bits are hard-wired during manufacturing, and A0 bit
is determined by the logic state of A0 pin. The A0 pin
can be connected to V
digital logic levels.
The following sections describe the communication
protocol to send or read the data code and write/read
the EEPROM using the I
“I
6.1
The write commands are used to load the configuration
bits and DAC input code to the DAC register, or to write
to the EEPROM of the device. The write command
types are defined by using three write command type
bits (C2, C1, C0).
types and their functions. There are three command
types for the MCP4725. The four “reserved” commands
in
the “reserved” commands. Write command protocol
examples are shown in
The input data code is coded as shown in
The MSB of the data is always transmitted first and the
format is unipolar binary.
TABLE 6-1:
© 2009 Microchip Technology Inc.
111111111111 (FFFh)
111111111110 (FFEh)
000000000010 (002h)
000000000001 (001h)
000000000000 (000h)
2
Table 6-2
C Serial Interface Communication”.
Input Code
THEORY OF OPERATION
Write Commands
2
are for future use. The MCP4725 ignores
C interface command. The MCP4725
INPUT DATA CODING
Table 6-2
DD
Figure 6-1
2
C interface. See Section 7.0
or V
Nominal Output Voltage
V
V
2 LSB
1 LSB
0
shows the write command
DD
DD
SS
, or actively driven by
- 1 LSB
- 2 LSB
and
2
Figure
(V)
C bus line, the
Table
6-2.
6-1.
6.1.1
The fast write command is used to update the DAC
register. The data in the EEPROM of the device is not
affected by this command. This command updates
Power-Down mode selection bits (PD1 and PD0) and
12 bits of the DAC input code in the DAC register.
Figure 6-1
command for the MCP4725 device.
6.1.2
In MCP4725, this command performs the same
function as the Fast Mode command in Section 6.1.1
“Write Command for Fast mode (C2 = 0, C1 = 0,
C0 = X, X = Don’t Care)”.
command protocol for the MCP4725.
As shown in
and fourth bytes are DAC input data. The last 4 bits (X,
X, X, X) in the fourth byte are don’t care bits.
The device executes the Master’s write command after
receiving the last byte (4th byte). The Master can send
a STOP bit to terminate the current sequence, or send
a Repeated START bit followed by an address byte. If
the device receives three data bytes continuously after
the 4th byte, it updates from the 2nd to the 4th data
bytes with the last three input data bytes.
The contents of the register are updated at the end of
the 4th byte. The device ignores any partially received
data bytes if the I
ends before completing the 4th byte.
6.1.3
When the device receives this command, it (a) loads
the configuration and data bits to the DAC register, and
(b) also writes the EEPROM. When the device is
writing the EEPROM, the RDY/BSY bit goes low and
stays low until the EEPROM write operation is
completed. The state of the RDY/BSY bit can be
monitored by a read command.
details of the this write command protocol and
Figure 6-3
shows the details of the read command.
WRITE COMMAND FOR FAST
MODE (C2 = 0, C1 = 0, C0 = X,
X = DON’T CARE)
WRITE COMMAND FOR DAC INPUT
REGISTER (C2 = 0, C1 = 1, C0 = 0)
WRITE COMMAND FOR DAC INPUT
REGISTER AND EEPROM
(C2 = 0, C1 = 1, C0 = 1)
shows an example of the fast write
Figure
2
C communication with the Master
6-2, the D11 - D0 bits in the third
Figure 6-2
MCP4725
Figure 6-2
DS22039D-page 23
shows the write
shows the