ltc1196-2bcs8-trpbf Linear Technology Corporation, ltc1196-2bcs8-trpbf Datasheet - Page 17

• Manufacturer Part Number: ltc1196-2bcs8-trpbf
• Description: 8-bit, So-8, 1msps Adcs With Auto-shutdown Options
• Manufacturer: Linear Technology Corporation

APPLICATIONS INFORMATION
When the CS pin is high (= supply voltage), the LTC1198
is in shutdown mode and draws only leakage current.
The status of the D
supply current during this time. There is no need to stop
D
without drawing current.
DATA (D
Figure 5. Supply Current vs Sample Rate for LTC1196/LTC1198
Operating on 5V and 2.7V Supplies
IN
and CLK with CS = high; they can continue to run
IN
/D
0.001
OUT
CLK
0.01
CS
0.1
10
)
1
100
LT1196 V
LT1198 V
LT1198 V
IN
1k
and CLK input has no effect on the
SAMPLE RATE (Hz)
START
CC
CC
1
CC
= 2.87V
= 5V
LT1198 V
= 5V
10k
THE DIGITAL SYSTEM CONTROLS DATA LINE
AND SENDS MUX ADDRESS TO LTC1198
SGL/DIFF
Figure 4. LTC1198 Operation with D
CC
100k
= 2.87V
2
1196/98 F05
1M
THE DIGITAL SYSTEM MUST RELEASE
ODD/SIGN
AND BEFORE THE 5TH FALLING CLK
DATA LINE AFTER 5TH RISING CLK
3
DUMMY
4
DUMMY BITS LATCHED
Minimize CS Low Time (LTC1198)
In systems that have signifi cant time between conver-
sions, lowest power drain will occur with the minimum
CS low time. Bringing CS low, transfering data as quickly
as possible, then bringing it back high will result in the
lowest current drain. This minimizes the amount of time
the device draws power.
OPERATING ON OTHER THAN 5V SUPPLIES
The LTC1196/LTC1198 operate from single 2.7V to 6V
supplies. To operate the LTC1196/LTC1198 on other than
5V supplies, a few things must be kept in mind.
Input Logic Levels
The input logic levels of CS, CLK and D
TTL on 5V supply. When the supply voltage varies, the input
logic levels also change (see typical curve of Digital Input
Logic Threshold vs Supply Voltage). For these two ADCs
to sample and convert correctly, the digital inputs have
to be in the logical low and high relative to the operating
supply voltage. If achieving micropower consumption is
desirable on the LTC1198, the digital inputs must go rail-
to-rail between supply voltage and ground (see Reducing
Power Consumption section).
IN
BY LTC1198
and D
5
OUT
Tied Together
LTC1198 TAKES CONTROL OF
DATA LINE ON 5TH FALLING CLK
LTC1198 CONTROLS DATA LINE AND SENDS
A/D RESULT BACK TO THE DIGITAL SYSTEM
LTC1196/LTC1198
IN
are made to meet
17
1196/98 F04
119698fa