Datasheet

26
LTC1290
1290fe
A “Quick Look” Circuit for the LTC1290
Users can get a quick look at the function and timing of the
LTC1290 by using the following simple circuit. REF
+
and
D
IN
are tied to V
CC
selecting a 5V input span, CH7 as a
single-ended input, unipolar mode, MSB-first format and
16-bit word length. ACLK and SCLK are tied together and
driven by an external clock. CS is driven at 1/128 the clock
rate by the CD4520 and D
OUT
outputs the data. All other
pins are tied to a ground plane. The output data from the
D
OUT
pin can be viewed on an oscilloscope which is set up
to trigger on the falling edge of CS.
U
SA
O
PP
L
IC
AT
ITY
P
I
CA
L
A “Quick Look” Circuit for the LTC1290
1290 TA02
LTC1290
0.1µF
22µF
f
CHO
CH1
CH2
CH3
CH4
CH5
CH6
CH7
COM
DGND
V
IN
{
TO
OSCILLOSCOPE
CD4520
CLK
EN
Q1
Q2
Q3
Q4
RESET
V
SS
V
DD
RESET
Q4
Q3
Q2
Q1
EN
CLK
CLOCK IN
2MHz MAX
5V
V
CC
ACLK
SCLK
D
IN
D
OUT
CS
REF
+
REF
–
V
–
AGND
f/128
Scope Trace of LTC1290 “Quick Look” Circuit
Showing A/D Output of 010101010101 (555
HEX
)
D
OUT
CS
ACLK/
SCLK
MSB
(B11)
DEGLITCHER
TIME
LSB
(B0)
FILLS
ZEROS
VERTICAL: 5V/DIV
HORIZONTAL: 1µs/DIV