LTC1196-1BC Linear Technology, LTC1196-1BC Datasheet - Page 17

• Manufacturer Part Number: LTC1196-1BC
• Description: 8-Bit/ SO-8/ 1MSPS ADCs with Auto-Shutdown Options
• Manufacturer: Linear Technology

A
When the CS pin is high (= supply voltage), the LTC1198
is in shutdown mode and draws only leakage current. The
status of the D
current during this time. There is no need to stop D
CLK with CS = high; they can continue to run without
drawing current.
DATA (D
PPLICATI
Figure 5. Supply Current vs Sample Rate for LTC1196/
LTC1198 Operating on 5V and 2.7V Supplies
IN
0.001
/D
0.01
0.1
OUT
10
CLK
CS
1
100
)
IN
LT1198 V
LT1196 V
LT1196 V
and CLK input has no effect on the supply
O
1k
U
SAMPLE RATE (Hz)
CC
START
CC
CC
S
= 5V
= 2.7V
1
= 5V
LT1198 V
I FOR ATIO
10k
U
THE DIGITAL SYSTEM CONTROLS DATA LINE
AND SENDS MUX ADDRESS TO LTC1198
CC
SGL/DIFF
Figure 4. LTC1198 Operation with D
100k
= 2.7V
2
W
1196/98 F05
THE DIGITAL SYSTEM MUST RELEASE
1M
ODD/SIGN
AND BEFORE THE 5TH FALLING CLK
DATA LINE AFTER 5TH RISING CLK
3
U
IN
and
DUMMY
4
DUMMY BITS LATCHED
Minimize CS Low Time (LTC1198)
In systems that have significant 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
meet 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).
BY LTC1198
IN
DUMMY
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
B7
IN
are made to
B6
1196/98 F04
17