LTC2668CUJ-16 View Datasheet(PDF) - Linear Technology
Part Name
Description
MFG CO.
LTC2668CUJ-16
Linear Technology
'LTC2668CUJ-16' PDF : 28 Pages View PDF
LTC2668
Operation
Table 1. Command Codes
COMMAND
C3 C2 C1 C0
0 0 0 0 Write Code to n
1 0 0 0 Write Code to All
0 1 1 0 Write Span to n
1 1 1 0 Write Span to All
0 0 0 1 Update n (Power Up)
1 0 0 1 Update All (Power Up)
0 0 1 1 Write Code to n, Update n (Power Up)
0 0 1 0 Write Code to n, Update All (Power Up)
1 0 1 0 Write Code to All, Update All (Power Up)
0 1 0 0 Power Down n
0 1 0 1 Power Down Chip (All DACs, Mux and Reference)
1 0 1 1 Monitor Mux
1 1 0 0 Toggle Select
1 1 0 1 Global Toggle
0 1 1 1 Config
1 1 1 1 No Operation
Table 2. DAC Addresses, n
ADDRESS
A3 A2 A1 A0
0 0 0 0 DAC 0
0 0 0 1 DAC 1
0 0 1 0 DAC 2
0 0 1 1 DAC 3
0 1 0 0 DAC 4
0 1 0 1 DAC 5
0 1 1 0 DAC 6
0 1 1 1 DAC 7
1 0 0 0 DAC 8
1 0 0 1 DAC 9
1 0 1 0 DAC 10
1 0 1 1 DAC 11
1 1 0 0 DAC 12
1 1 0 1 DAC 13
1 1 1 0 DAC 14
1 1 1 1 DAC 15
Data Transfer Functions
The DAC input-to-output transfer functions for all output
ranges and resolutions are shown in Figures 2a and 2b.
The input code is in straight binary format for all ranges.
Serial Interface
When the CS/LD pin is taken low, the data on the SDI
pin is loaded into the shift register on the rising edge
of the clock (SCK pin). The 4-bit command, C3-C0, is
loaded first, followed by the 4-bit DAC address, A3-A0,
and finally the 16-bit data word in straight binary format.
For the LTC2668-16, the data word comprises the 16-bit
input code, ordered MSB-to-LSB. For the LTC2668-12,
the data word comprises the 12-bit input code, ordered
MSB-to-LSB, followed by four don’t-care bits. Data can
only be transferred to the LTC2668 when the CS/LD signal
is low. The rising edge of CS/LD ends the data transfer
and causes the device to carry out the action specified in
the 24-bit input word. The complete sequence is shown
in Figure 3a.
10
2.5V INTERNAL REFERENCE
7.5
5
2.5
0
–2.5
–5
–7.5
–10
0
16384
0V TO 5V RANGE
0V TO 10V RANGE
±5V RANGE
±10V RANGE
±2.5V RANGE
32768 49152 65535
STRAIGHT BINARY CODE (DECIMAL EQUIVALENT)
2668 F01a
Figure 2a. LTC2668-16 Transfer Function
10
2.5V INTERNAL REFERENCE
7.5
5
2.5
0
–2.5
–5
–7.5
–10
0
1024
0V TO 5V RANGE
0V TO 10V RANGE
±5V RANGE
±10V RANGE
±2.5V RANGE
2048
3072
4095
STRAIGHT BINARY CODE (DECIMAL EQUIVALENT)
2668 F02b
Figure 2b. LTC2668-12 Transfer Function
2668fa
16
For more information www.linear.com/LTC2668
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