MAX521BCAG Maxim Integrated Products, MAX521BCAG Datasheet - Page 14

• Manufacturer Part Number: MAX521BCAG
• Description: IC DAC OCTAL SER 8BIT R/R 24SSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX521BCAG

• Settling Time: 6µs
• Number Of Bits: 8
• Data Interface: I²C, Serial
• Number Of Converters: 8
• Voltage Supply Source: Single Supply
• Power Dissipation (max): 640mW
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 24-SSOP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Quad/Octal, 2-Wire Serial 8-Bit DACs
with Rail-to-Rail Outputs
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 13a). 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 13b).
The MAX520 contains four matched voltage-output
DACs, and the MAX521 contains eight. The DACs are
inverted R-2R ladder networks that convert 8-bit digital
Figure 12. Repeated START Conditions
Figure 13. Early STOP Conditions
14
SDA
CONDITION
SDA
______________________________________________________________________________________
START
(a)
(b)
SDA
0
SDA
0
1
CONDITION
CONDITION
ADDRESS BYTE
START
START
0
0
(ADDRESSING DAC2)
(DEVICE 0)
COMMAND BYTE
0
1
0
0
0
0
1
1
ADDRESS BYTE
ADDRESS BYTE
0
0
0
0
0
0
1
1
1
0
ACK
AD1 AD0 0 0
AD1 AD0 0 0 0
0 0
0
0 OR AD2
0 OR AD2
ACK
Early Stop Conditions
0
Analog Section
1
0
ADDRESSING DAC1
COMMAND BYTE
ACK
ACK
0
1
DAC Operation
OUTPUT BYTE
(FULL SCALE)
0
1
0 0
COMMAND BYTE
0
INTERRUPTED
1
(
0
DEVICE 1's
DAC2 INPUT LATCH
SET TO FULL SCALE
COMMAND BYTE
1
(POWER DOWN)
0
0
0 1 1
(RST) (PD)
RST 1
0 1
1
(PD)
1
STOP CONDITION
ACK
0
0
1
0
EARLY
ACK
0
1
0
)
(
0 0
1
STOP
CONDITION
ONLY DEVICE 1's DAC2 OUTPUT LATCH SET TO FULL
SCALE. DEVICE 0's OUTPUT LATCHES UNCHANGED.
words into equivalent analog output voltages in propor-
tion to the applied reference voltages. For both
devices, DAC0–DAC3 each have separate reference
inputs, while the MAX521’s DAC4–DAC7 all share a
common reference input. Figure 14 shows a simplified
diagram of one DAC.
The MAX520/MAX521 can be used for multiplying appli-
cations. The reference accepts a 0V to V
both DC and AC signals. The voltage at each REF input
sets the full-scale output voltage for its respective
DAC(s). The reference voltage must be positive. The
DAC’s input impedance is code dependent, with the
lowest value occurring when the input code is 55 hex or
0101 0101, and the maximum value occurring when the
input code is 00 hex. Since the REF input resistance
ACK
OUTPUT BYTE
(FULL SCALE)
1
(
MAX520/MAX521's STATES
REMAIN UNCHANGED
1
1
(
INTERRUPTED
OUTPUT BYTE
DEVICE 0's
DAC1 INPUT LATCH
SET TO FULL SCALE
1 1
1
1
0
STOP CONDITION
1
0
1
EARLY
ACK
0
)
)
REPEATED START
CONDITION
(
MAX520/MAX521 POWER DOWN;
INPUT LATCHES UNCHANGED IF
RST = 0, DAC OUTPUTS RESET IF
RST = 1.
0 1
ADDRESS BYTE
0 1
(DEVICE 1)
)
0 0
Reference Inputs
1 0
DD
ACK
0
)
voltage,