LTC1417C Linear Technology, LTC1417C Datasheet - Page 23

• Manufacturer Part Number: LTC1417C
• Description: Low Power 14-Bit/ 400ksps Sampling ADC Converter with Serial I/O
• Manufacturer: Linear Technology

TYPICAL APPLICATIONS
Figure 21 shows the connections necessary for interfacing
the LTC1417 and LTC1391 8-channel signal acquisition
system to an SPI port. With the sample software routine
shown in Listing A, the SPI uses MOSI to send serial data
to the LTC1391 8-channel multiplexer, selecting one of
eight MUX channels.
While data is sent to the LTC1391, SPI uses MISO to
retrieve conversion data from the LTC1417. After the data
transfer is complete, the conversion start signal is sent to
IN1
IN2
IN3
IN4
IN5
IN6
IN7
IN8
1
2
3
4
5
6
7
8
S0
S1
S2
S3
S4
S5
S6
S7
LTC1391
Figure 21. 0V to 4.096V, 8-Channel Data Acquisition System Configured
for Control and Data Retrieval by a 68HC11 C. Code is Shown in Listing A
DGND
D
CLK
OUT
D
V
V
CS
IN
U
D
+
–
16
15
14
13
12
11
10
9
5V
0.1 F
NC
10 F
1 F
NC
5V
1
2
3
4
5
6
7
8
the LTC1417. The end of conversion is signaled by a logic
high on the BUSY output. When this occurs, data is
exchanged between the LTC1417/LTC1391 and the
controller.
The timing diagram in Figure 22 shows the relation be-
tween MUX channel selection data and the conversion
data that are simultaneously exchanged. There is a two
conversion delay between the MUX data selects a given
channel and when that channel’s data is retrieved.
A
A
V
REFCOMP
AGND
EXTCLKIN
SCLK
CLKOUT
IN
IN
REF
+
–
LTC1417
CONVST
DGND
SHDN
BUSY
D
V
V
OUT
RD
DD
SS
16
15
14
13
12
11
10
9
5V
10 F
SS
MISO
CLK
MOSI
MC68HC11
PORT C, BIT 7
PORT C, BIT 0
1417 F21
LTC1417
23