LTC1409 LINER [Linear Technology], LTC1409 Datasheet - Page 7

• Manufacturer Part Number: LTC1409
• Description: 12-Bit, 800ksps Sampling A/D Converter with Shutdown
• Manufacturer: LINER [Linear Technology]

PI FU CTIO S
FU CTIO AL BLOCK DIAGRA
CONVST (Pin 23): Conversion Start Signal. This active
low signal starts a conversion on its falling edge.
CS (Pin 24): Chip Select. The input must be low for the
ADC to recognize CONVST and RD inputs.
BUSY (Pin 25): The BUSY output shows the converter
status. It is low when a conversion is in progress. Data
valid on the rising edge of BUSY.
TEST CIRCUITS
DBN
U
U
(a) Hi-Z to V
and V
U
REFCOMP
1k
(4.06V)
AGND
DGND
U
– A
Load Circuits for Access Timing
+A
V
OL
REF
IN
IN
to V
OH
OH
U
C
L
4k
REF AMP
2.5V REF
INTERNAL
DBN
CLOCK
(b) Hi-Z to V
and V
OH
5V
NAP/SLP
1k
to V
C
LTC1409 • TC01
L
12-BIT CAPACITIVE DAC
SUCCESSIVE APPROXIMATION
OL
W
OL
C
C
SHDN
SAMPLE
SAMPLE
CONTROL LOGIC
REGISTER
RD
CONVST
V
using 10 F tantalum in parallel 0.1 F or 10 F ceramic.
OV
5V logic, short to Pin 28. For 3V logic, short to supply
of the logic being driven.
AV
10 F tantalum in parallel with 0.1 F or 10 F ceramic.
SS
DD
DD
DBN
(Pin 26): – 5V Negative Supply. Bypass to AGND
CS
(Pin 27): Positive Supply for Output Drivers. For
(Pin 28): 5V Positive Supply. Bypass to AGND
BUSY
(a) V
Load Circuits for Bus Relinquish Time
1k
ZEROING SWITCHES
12
OH
+
–
COMP
to Hi-Z
OUTPUT LATCHES
100pF
DBN
LTC1409 • BD
(b) V
LTC1409
•
•
•
OL
D11
D0
AV
OV
OGND
5V
DD
DD
to Hi-Z
1k
LTC1409 • TC02
100pF
7