LTC1092 LINER [Linear Technology], LTC1092 Datasheet - Page 11

• Manufacturer Part Number: LTC1092
• Description: 1-, 2-, 6- and 8-Channel, 10-Bit Serial I/O Data Acquisition Systems
• Manufacturer: LINER [Linear Technology]

The LTC1091/LTC1092/LTC1093/LTC1094 are data
acquisiton components that contain the following func-
tional blocks:
1. 10-Bit Successive Approximation A/D Converter
2. Analog Multiplexer (MUX)
3. Sample-and-Hold (S/H)
4. Synchronous, Half-Duplex Serial Interface
5. Control and Timing Logic
DIGITAL CONSIDERATIONS
1. Serial Interface
The LTC1091/LTC1093/LTC1094 communicate with
microprocessors and other external circuitry via a syn-
chronous, half-duplex, 4-wire serial interface while the
LTC1092 uses a 3-wire interface (see Operating Sequence).
The clock (CLK) synchronizes the data transfer with each
bit being transmitted on the falling CLK edge and captured
on the rising CLK edge in both transmitting and receiving
A
TEST CIRCUITS
PPLICATI
D
CLK
OUT
D
CS
LTC1093/LTC1094
IN
O
U
START
S
I FOR ATIO
1
U
D
CLK
OUT
CS
2
LTC1092
W
3
Voltage Waveforms for t
U
4
systems. The LTC1091/LTC1093/LTC1094 first receive
input data and then transmit back the A/D conversion
result (half-duplex). Because of the half-duplex operation,
D
over just three wires: CS, CLK and DATA (D
Data transfer is initiated by a falling chip select (CS) signal.
After CS falls, the LTC1091/LTC1093/LTC1094 looks for a
start bit. After the start bit is received, a 3-bit input word
(6 bits for the LTC1093/LTC1094) is shifted into the D
input which configures the LTC1091/LTC1093/LTC1094
and starts the conversion. After one null bit, the result of
the conversion is output on the D
data exchange, CS should be brought high. This resets the
LTC1091/LTC1093/LTC1094 in preparation for the next
data exchange.
The LTC1092 does not require a configuration input word
and has no D
shown in the LTC1092 Operating Sequence. After CS falls,
1
IN
5
and D
t
en
en
0.4V
OUT
6
IN
may be tied together allowing transmission
pin. A falling CS initiates data transfer as
B9
1091/2/3/4 TC08
7
LTC1093/LTC1094
LTC1091/LTC1092
t
en
0.4V
OUT
B9
line. At the end of the
1091/2/3/4 TC09
IN
/D
OUT
11
).
IN