LTC2635CUD-LMO8#TRPBF Linear Technology, LTC2635CUD-LMO8#TRPBF Datasheet - Page 24

• Manufacturer Part Number: LTC2635CUD-LMO8#TRPBF
• Description: IC DAC 8BIT I2C QUAD 16-QFN
• Manufacturer: Linear Technology

Specifications of LTC2635CUD-LMO8#TRPBF

• Settling Time: 3.5µs
• Number Of Bits: 8
• Data Interface: I²C
• Number Of Converters: 4
• Voltage Supply Source: Single Supply
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 16-QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power Dissipation (max): -

The 10ppm/°C, 1.25V (LTC2635-LMI/-LMX/-LMO/-LZ) or
2.048V (LTC2635-HMI/-HZ) internal reference is available
at the REF pin. Adding bypass capacitance to the REF pin
will improve noise performance; and up to 10µF can be
driven without oscillation. This output must be buffered
when driving an external DC load current.
Alternatively, the DAC can operate in External Reference
mode using command 0111b. In this mode, an input voltage
supplied externally to the REF pin provides the reference
(1V ≤ V
external reference voltage supplied sets the full-scale DAC
output voltage. External Reference mode is the power-on
default for LTC2635-LMX.
The reference mode of LTC2635-HZ/-LZ/-HMI/-LMI/-LMO
(Internal Reference power-on default), can be changed by
software command after power up. The same is true for
LTC2635-LMX (External Reference power-on default).
LTC2635
operation

Write Word Protocol for LTC2635
Input Word (LTC2635-12)
Input Word (LTC2635-10)
Input Word (LTC2635-8)
REF
≤ V
C3
C3
C3
S
CC
C2
C2
C2
) and the supply current is reduced. The
SLAVE ADDRESS
C1
C1
C1
1ST DATA BYTE
1ST DATA BYTE
1ST DATA BYTE
C0
C0
C0
A3
A3
A3
W
A2
A2
A2
ACK
A1
A1
A1
Figure 3. Command and Data Input Format
A0
A0
A0
1ST DATA BYTE
D11
D9
D7
D10
D8
D6
ACK
D9
D7
D5
2ND DATA BYTE
2ND DATA BYTE
2ND DATA BYTE
D8
D6
D4
2ND DATA BYTE
Power-Down Mode
For power-constrained applications, power-down mode can
be used to reduce the supply current whenever less than
four DAC outputs are needed. When in power-down, the
buffer amplifiers, bias circuits, and integrated reference
circuits are disabled, and draw essentially zero current.
The DAC amplifier outputs are put into a high-impedance
state, and the output pins are passively pulled to ground
through individual 200k resistors (LTC2635-LMI/-LMX/
-LZ/-HMI/-HZ). For the LTC2635-LMO options, the out-
put pins are not passively pulled to ground, but are also
placed in a high-impedance state (open-circuited state)
during power-down, typically drawing less than 0.1µA.
The LTC2635-LMO options power-up with all DAC outputs
in this high-impedance state. They remain that way until
given a software or hardware update command. For all
LTC2635 options, input- and DAC-register contents are
not disturbed during power-down.
INPUT WORD
D7
D5
D3
D6
D4
D2
ACK
D5
D3
D1
D4
D2
D0
3RD DATA BYTE
D3
D1
X
D2
D0
X
ACK
D1
X
X
3RD DATA BYTE
3RD DATA BYTE
3RD DATA BYTE
D0
P
X
X
X
X
X
X
X
X
X
X
X
2635 F03
X
X
X
2635fb