MAX517 Maxim, MAX517 Datasheet - Page 12

• Manufacturer Part Number: MAX517
• Description: 2-Wire Serial 8-Bit DACs with Rail-to-Rail Outputs
• Manufacturer: Maxim

2-Wire Serial 8-Bit DACs with
Rail-to-Rail Outputs
It is possible to interrupt a transmission to a device with
a new START (repeated start) condition (perhaps
addressing another device), which leaves the input
Figure 12. MAX517/MAX518/MAX519 Used in a Typical I
Application Circuit
Figure 13. Repeated START Conditions
12
SDA
CONDITION
SDA
______________________________________________________________________________________
START
+5V
0
0
1
ADDRESS BYTE
0
0
(ADDRESSING DAC0)
(DEVICE 0)
SDA SCL
COMMAND BYTE
0
1
C
0
1
0
0
Additional START Conditions
0
0
SCL
SDA
SCL
SDA
AD0
AD1
SCL
SDA
AD0
AD1
0
0
E
ACK
MAX517
X24C04
MAX518
SINGLE
2
XICOR
0 0
0
DUAL
DAC
PROM
DAC
ACK
0
0
1
OUT0
OUT1
OUT0
ADDRESSING DAC0
COMMAND BYTE
0
1
OUTPUT BYTE
(FULL SCALE)
0
1
0
1
(
INPUT LATCH SET
1
0
DEVICE 1's DAC0
TO FULL SCALE.
2
0 0
1
C
1
ACK
0
1
ACK
1
0
)
(
1
STOP
CONDITION
latches with data that has not been transferred to the
output latches (Figure 13). Only the currently addressed
device will recognize a STOP condition and transfer
data to its output latches. If the device is left with data in
its input latches, the data can be transferred to the out-
put latches the next time the device is addressed, as
long as it receives at least one command byte and a
STOP condition.
The addressed device recognizes a STOP condition at
any point in a transmission. If the STOP occurs during a
command byte, all previous uninterrupted command
and output byte pairs are accepted, the interrupted
command byte is ignored, and the transmission ends
(Figure 14a). If the STOP occurs during an output byte,
all previous uninterrupted command and output byte
pairs are accepted, the final command byte’s PD and
RST bits are accepted, the interrupted output byte is
ignored, and the transmission ends (Figure 14b).
The MAX518 and MAX519 contain two matched volt-
age-output DACs. The MAX517 contains a single DAC.
The DACs are inverted R-2R ladder networks that con-
vert 8-bit digital words into equivalent analog output
voltages in proportion to the applied reference volt-
ages. The MAX518 has both DAC’s reference inputs
connected to V
gram of one DAC.
The MAX517 and MAX519 can be used for multiplying
applications. The reference accepts a 0V to V
ONLY DEVICE 1's DAC0 OUTPUT LATCH SET TO FULL
SCALE. DEVICE 0's OUTPUT LATCH UNCHANGED.
OUTPUT BYTE
(FULL SCALE)
1
1
(
SET TO FULL SCALE.
DAC0 INPUT LATCH
1
1
1
DEVICE 0's
1
DD
ACK
0
. Figure 15 shows a simplified dia-
MAX517/MAX519 Reference Inputs
)
REPEATED START
CONDITION
0 1
ADDRESS BYTE
Early STOP Conditions
0 1
(DEVICE 1)
)
Analog Section
1 0
DAC Operation
1 0
ACK
0
DD
volt-