Datasheet
MAX5803/MAX5804/MAX5805
Ultra-Small, Single-Channel, 8-/10-/12-Bit Buffered Output
Voltage DACs with Internal Reference and I
2
C Interface
19Maxim Integrated
Readback of all other registers is not directly supported.
All requests to read unsupported registers read back
the device’s current status and configuration settings as
shown in Table 2. The status register contains information
on the current clear, gate, and load status of the device
(with a one indicating an asserted status), as well as user
configuration settings for the reference, power-down,
AUX mode, and default operation.
Interface Verification I
2
C Readback
Operations
While the MAX5803/MAX5804/MAX5805 support
standard I
2
C readback of selected registers, it is also
capable of functioning in an interface verification mode.
This mode is accessed any time a readback operation
follows an executed write mode command. In this mode,
the last executed three-byte command is read back in its
entirety. This behavior allows verification of the interface.
Figure 5. Multiple Register Write Sequence (Standard I
2
C Protocol)
Figure 4. I
2
C Single Register Write Sequence
SCL
AW 20 19 18 17 A16 15 14 13 12 11 10 9A8
START
SDA
WRITE ADDRESS
BYTE #1: I
2
C SLAVE ADDRESS
WRITE COMMAND
BYTE #2: COMMAND BYTE
(B[23:16])
WRITE DATA
BYTE #3: DATA HIGH BYTE
(B[15:8])
WRITE DATA
BYTE #4: DATA LOW BYTE
(B[7:0])
212223
STOP
7 6 5 4 3 2 1A0
ACK. GENERATED BY MAX5803/MAX5804/MAX5805
COMMAND EXECUTED
1 0 A1 A0100
A
SCL
AW
20 19 18 17
A
16
15 14 13 12 11 10 9A8
START
SDA
WRITE ADDRESS
BYTE #1: I
2
C SLAVE ADDRESS
WRITE COMMAND1
BYTE #2: COMMAND1 BYTE
(B[23:16])
WRITE DATA1
BYTE #3: DATA1 HIGH BYTE
(B[15:8])
21
0 0 1 1 0 A1 A0
2223
STOP
7 6 5 4 3 2 1A0
WRITE DATA1
BYTE #4: DATA1 LOW BYTE
(B[7:0])
20 19 18 17 A16 15 14 13 12 11 10 9A8212223 7 6 5 4 3 2 1A0
ADDITIONAL COMMAND AND
DATA PAIRS (3 BYTE BLOCKS)
COMMAND1
EXECUTED
COMMANDn
EXECUTED
BYTE #5: COMMANDn BYTE
(B[23:16])
BYTE #6: DATAn HIGH BYTE
(B[15:8])
BYTE #7: DATAn LOW BYTE
(B[7:0])
ACK. GENERATED BY MAX5803/MAX5804/MAX5805A