LTC1417 LINER [Linear Technology], LTC1417 Datasheet - Page 27

• Manufacturer Part Number: LTC1417
• Description: Low Power 14-Bit, 400ksps Sampling ADC Converter with Serial I/O
• Manufacturer: LINER [Linear Technology]

TYPICAL APPLICATIONS
Figure 23 uses the DG408 to select one of eight 2.048V
bipolar signals and apply it to the LTC1417’s analog input.
The circuit is designed to connect to a 68HC11 C. The
MUX’s parallel input is connected to the controller’s port
C and the LTC1417’s serial interface is accessed through
the controller’s SPI interface.
IN1
IN2
IN3
IN4
IN5
IN6
IN7
IN8
1
2
3
4
5
6
7
8
S1
S2
S3
S4
S5
S6
S7
S8
DG408
Figure 23. With an Input Range of 2.048V for Each of Eight Inputs,
This Data Acquisition System is Configured for Communication with the 68HC11 C
GND
V
V
EN
A2
A1
A0
D
+
–
13
3
14
2
U
5V
0.1 F
– 5V
0.1 F
10 F
1 F
NC
5V
The sequence to generate a conversion is shown in sample
program Listing B. The first step selects a MUX channel.
This is followed by initiating a conversion and waiting for
BUSY to go high, signifying end of conversion. Once BUSY
goes low, the SPI is used to retrieve the 14-bit conversion
data. The timing relationships between the various control
signals and data transmission are shown in Figure 24.
1
2
3
4
5
6
7
8
A
A
V
REFCOMP
AGND
EXTCLKIN
SCLK
CLKOUT
IN
IN
REF
+
–
LTC1417
CONVST
SHDN
DGND
BUSY
D
V
V
OUT
RD
DD
SS
16
15
14
13
12
11
10
9
5V
– 5V
PORT C, BIT 7
PORT C, BIT 6
SS
MISO
CLK
PORT C, BIT 2
PORT C, BIT 1
PORT C, BIT 0
MC68HC11
LTC1417
1417 F23
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