AD5640 Analog Devices, AD5640 Datasheet - Page 20

• Manufacturer Part Number: AD5640
• Manufacturer: Analog Devices

Specifications of AD5640

• Resolution (bits): 14bit
• Dac Update Rate: 125kSPS
• Dac Settling Time: 8µs
• Max Pos Supply (v): +5.5V
• Single-supply: Yes
• Dac Type: Voltage Out
• Dac Input Format: Ser,SPI

AD5620/AD5640/AD5660
AD5660-to-68HC11/68L11 Interface
Figure 46 shows a serial interface between the AD5660 and the
68HC11/68L11 microcontroller. SCK of 68HC11/68L11 drives
the SCLK of AD5660, and the MOSI output drives the serial
data line of the DAC. The SYNC signal is derived from a port
line (PC7). The setup conditions for correct operation of this
interface are as follows: The 68HC11/68L11 should be con-
figured so that its CPOL bit is 0, and its CPHA bit is 1. When
data is being transmitted to the DAC, the SYNC line is taken
low (PC7). When the 68HC11/68L11 is configured in this way,
data appearing on the MOSI output is valid on the falling edge
of SCK. Serial data from the 68HC11/68L11 is transmitted in
8-bit bytes with only eight falling clock edges occurring in the
transmit cycle. Data is transmitted MSB first. To load data to the
AD5660, PC7 is left low after the first eight bits are transferred, a
second serial write operation is performed to the DAC, and PC7
is taken high at the end of this procedure.
AD5660-to-80C51/80L51 Interface
Figure 47 shows a serial interface between the AD5660 and the
80C51/80L51 microcontroller. The setup for the interface is as
follows: TxD of the 80C51/80L51 drives SCLK of the AD5660,
and RxD drives the serial data line of the part. The SYNC signal
is again derived from a bit-programmable pin on the port. In
this case, Port Line P3.3 is used. When data is to be transmitted
to the AD5660, P3.3 is taken low. The 80C51/80L51 transmit
1
ADDITIONAL PINS OMITTED FOR CLARITY
68HC11/68L11
Figure 46. AD5660-to-68HC11/68L11 Interface
MOSI
SCK
PC7
1
AD5660
SYNC
SCLK
DIN
1
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data only in 8-bit bytes; therefore, only eight falling clock edges
occur in the transmit cycle. To load data to the DAC, P3.3 is left
low after the first eight bits are transmitted, and a second write
cycle is initiated to transmit the second byte of data. P3.3 is taken
high following the completion of this cycle. The 80C51/80L51
output the serial data LSB first; however, the AD5660 requires
its data with the MSB as the first bit received. The 80C51/80L51
transmit routine should take this into account.
AD5660-to-MICROWIRE Interface
Figure 48 shows an interface between the AD5660 and any
MICROWIRE-compatible device. Serial data is shifted out on
the falling edge of the serial clock and is clocked into the
AD5660 on the rising edge of the SK.
1
1
ADDITIONAL PINS OMITTED FOR CLARITY
ADDITIONAL PINS OMITTED FOR CLARITY
80C51/80L51
MICROWIRE
Figure 47. AD5660-to-80C51/80L51 Interface
Figure 48. AD5660-to-MICROWIRE Interface
P3.3
RxD
TxD
SO
CS
SK
1
1
AD5660
SYNC
SCLK
DIN
AD5660
SYNC
SCLK
DIN
1
1