Datasheet

MAX5813/MAX5814/MAX5815
Ultra-Small, Quad-Channel, 8-/10-/12-Bit Buffered
Output DACs with Internal Reference and I
2
C Interface
18Maxim Integrated
Figure 5. Multiple Register Write Sequence (Standard I
2
C Protocol)
Figure 6. Standard I
2
C Register Read Sequence
Combined Format I
2
C Readback Operations
Each readback sequence is framed by a START or
Repeated START condition and a STOP condition. Each
word is 8 bits long and is followed by an acknowledge
clock pulse as shown in Figure 6. The first byte contains
the address of the MAX5813/MAX5814/MAX5815 with
R/W = 0 to indicate a write. The second byte contains
the register that is to be read back. There is a Repeated
START condition, followed by the device address with
R/W = 1 to indicate a read and an acknowledge clock.
The master has control of the SCL line but the MAX5813/
MAX5814/MAX5815 take over the SDA line. The final two
bytes in the frame contain the register data readback
followed by a STOP condition. If additional bytes beyond
those required to readback the requested data are pro-
vided, the MAX5813/MAX5814/MAX5815 will continue to
readback ones.
Readback of individual CODE registers is supported for
the CODE command (B[23:20] = 0000). For this com-
mand, which supports a DAC address, the requested
channel CODE register content will be returned; if all
DACs are selected, CODEA content will be returned.
Readback of individual DAC registers is supported for
all LOAD commands (B[23:20] = 0001, 0010, or 0011).
For these commands, which support a DAC address, the
requested DAC register content will be returned. If all
DACs are selected, DACA content will be returned.
Modified readback of the POWER register is supported
for the POWER command (B[23:20] = 0100). The power
status of each DAC is reported in locations B[3:0], with a
1 indicating the DAC is powered down and a 0 indicating
the DAC is operational (see Table 3).
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 A3 A2 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])
*I
2
C SLAVE ADDRESS FOR THE TSSOP PACKAGE IS USED
ACK. GENERATED BY MAX5813/MAX5814/MAX5815
A
READ DATA
BYTE #4: DATA 1 HIGH
BYTE (B[15:8])
READ DATA
BYTE #5: DATA 1 LOW
BYTE (B[7:0])
REPEATED
START
READ ADDRESS
BYTE #3: I
2
C SLAVE
ADDRESS*
WRITE ADDRESS
BYTE #1: I
2
C SLAVE
ADDRESS*
WRITE COMMAND 1
BYTE #2: COMMAND 1
BYTE
*I
2
C SLAVE ADDRESS FOR THE TSSOP PACKAGE IS USED
ACK. GENERATED BY MAX5813/MAX5814/MAX5815 ACK. GENERATED BY I
2
C MASTER
A
START STOP
SCL
SDA
001A3A2A1A0W A
A
A0
0N
0
01A3 A2 A1 A0 RAD DDDDDDD DDDDDDDD
~A
ANNNNN