LTC2668CUJ-16TRPBF View Datasheet(PDF) - Linear Technology
Part Name
Description
MFG CO.
LTC2668CUJ-16TRPBF
Linear Technology
'LTC2668CUJ-16TRPBF' PDF : 28 Pages View PDF
LTC2668
Operation
Manual Span Operation
Multiple output ranges are not needed in all applications.
By tying the MSPAN pins (MSP2, MSP1 and MSP0) to GND
and/or AVP, any output range can be hardware-configured
without additional operational overhead. Zero-scale and
mid-scale reset options are also available for the unipolar
modes (see Table 4).
Table 4. MSPAN Pin Configurations
MSP2 MSP1 MSP0
0
0
0
0
0 AVP
0 AVP 0
0 AVP AVP
AVP 0
0
OUTPUT
RANGE
±10V
±5V
±2.5V
0V to 10V
0V to 10V
RESET
CODE
Mid-Scale
Mid-Scale
Mid-Scale
Zero-Scale
Mid-Scale
MANUAL
SPAN
X
X
X
X
X
SOFT-
SPAN
AVP 0 AVP 0V to 5V Zero-Scale X
AVP AVP 0 0V to 5V Mid-Scale
X
AVP AVP AVP 0V to 5V Zero-Scale
X
Monitor Mux
The LTC2668 includes a high voltage multiplexer (mux)
for surveying the channel outputs.
The MUX pin is intended for use with high impedance
inputs only; the output impedance of the multiplexer is
2.2kΩ. Continuous DC output current at the MUX pin must
be limited to ±1mA to avoid damaging internal circuits.
The output voltage range of the multiplexer is from V– to
V+ – 1.4V. The output is disabled (high impedance) at
power-up.
The syntax and codes for the Mux command are shown
in Figure 5 and Table 5.
Table 5. Monitor Mux Control Codes
M4 M3 M2 M1 M0
MUX PIN OUTPUT
0
0
0
0
0
Disabled (Hi-Z)
1
0
0
0
0
1
0
0
0
1
1
0
0
1
0
1
0
0
1
1
1
0
1
0
0
1
0
1
0
1
1
0
1
1
0
1
0
1
1
1
1
1
0
0
0
1
1
0
0
1
1
1
0
1
0
1
1
0
1
1
1
1
1
0
0
1
1
1
0
1
1
1
1
1
0
1
1
1
1
1
VOUT0
VOUT1
VOUT2
VOUT3
VOUT4
VOUT5
VOUT6
VOUT7
VOUT8
VOUT9
VOUT10
VOUT11
VOUT12
VOUT13
VOUT14
VOUT15
Toggle Operations
Some systems require that DAC outputs switch repetitively
between two voltage levels. Examples include introducing
a small AC bias, or independently switching between ‘on’
and ‘off’ states. The LTC2668 toggle function facilitates
these kinds of operations by providing two input registers
(A and B) per DAC channel.
Toggling between A and B is controlled by three signals.
The first of these is the toggle select command, which acts
on a data field of 16 bits, each of which controls a single
channel (see Figure 6). The second is the global toggle
command, which controls all selected channels using the
global toggle bit TGB (see Figure 7). Finally, the TGP pin
MUX COMMAND
DON’T CARE
MUX CONTROL CODE
1 0 1 1 X X X X X X X X X X X X X X X M4 M3 M2 M1 M0
2668 F05
Figure 5. Mux Command
For more information www.linear.com/LTC2668
2668fa
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