LTC1198-1BCS8 Linear Technology, LTC1198-1BCS8 Datasheet - Page 16

• Manufacturer Part Number: LTC1198-1BCS8
• Description: IC ADC 8BIT 750KHZ SAMPL 8-SOIC
• Manufacturer: Linear Technology

Specifications of LTC1198-1BCS8

• Number Of Bits: 8
• Sampling Rate (per Second): 750k
• Data Interface: Serial
• Number Of Converters: 1
• Power Dissipation (max): 50mW
• Voltage Supply Source: Single Supply
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

LTC1196/LTC1198
APPLICATIONS INFORMATION
Dummy Bits
The last two bits of the input word following the MUX ad-
dress are dummy bits. Either bit can be a logical one or a
logical zero . These two bits allow the ADC 2.5 clocks to
acquire the input signal after the channel selection.
A/D Conversion Result
Both the LTC1196 and the LTC1198 have the A/D conver-
sion result appear on the D
the operating sequences in Figures 1 and 2). Data on the
D
The D
edge by the digital systems. Data on the D
valid for a minimum time of t
capture to occur (see Figure 3).
16
Figure 3. Voltage Waveform for D
OUT
DATA (D
line is updated on the rising edge of the CLK line.
OUT
D
CLK
OUT
IN
data should also be captured on the rising CLK
/D
OUT
CLK
CS
)
V
t
hDO
IH
t
dDO
START
1
OUT
hDO
THE DIGITAL SYSTEM CONTROLS DATA LINE
OUT
AND SENDS MUX ADDRESS TO LTC1198
line after two null bits (see
THE DIGITAL SYSTEM MUST RELEASE DATA LINE AFTER
Figure 4. LTC1198 Operation with D
(30ns at 5V) to allow the
SGL/DIFF
Delay Time, t
5TH RISING CLK AND BEFORE THE 5TH FALLING CLK
2
OUT
1196/98 TC03
ODD/SIGN
line remains
V
V
dDO
3
OL
OH
and t
DUMMY
hDO
4
DUMMY BITS LATCHED
Unipolar Transfer Curve
The LTC1196/LTC1198 are permanently confi gured for
unipolar only. The input span and code assignment for this
conversion type are shown in the following fi gures.
Operation with D
The LTC1198 can be operated with D
together. This eliminates one of the lines required to com-
municate to the digital systems. Data is transmitted in both
directions on a single wire. The pin of the digital systems
connected to this data line should be confi gurable as either
an input or an output. The LTC1198 will take control of
the data line and drive it LOW on the fi fth falling CLK edge
after the START bit is received (see Figure 4). Therefore,
the port line of the digital systems must be switched to
an input before this happens to avoid a confl ict.
BY LTC1198
IN
1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 0
0 0 0 0 0 0 0 1
0 0 0 0 0 0 0 0
5
and D
•
•
•
OUT
OUTPUT CODE
1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 0
0 0 0 0 0 0 0 1
0 0 0 0 0 0 0 0
0V
LTC1198 TAKES CONTROL OF
DATA LINE ON 5TH FALLING CLK
Tied Together
•
•
•
LTC1198 CONTROLS DATA LINE AND SENDS
A/D RESULT BACK TO THE DIGITAL SYSTEM
1LSB
Unipolar Transfer Curve
IN
Unipolar Output Code
and D
INPUT VOLTAGE
V
V
REF
REF
1LSB
0V
– 1LSB
– 2LSB
•
•
•
OUT
Tied Together
INPUT VOLTAGE
(V
REF
4.9805V
4.9609V
0.0195V
= 5.000V)
V
0V
2LSB
REF
•
•
•
IN
–
V
and D
1LSB
REF
1196/98 F04
–
V
REF
OUT
V
1196/98 AI04
IN
119698fb
tied