Datasheet

LTC1099
5
PIN FUNCTIONS
UUU
V
IN
(Pin 1): Analog Input.
DB0 to DB3 (Pins 2 to 5): Data Outputs. DB0 = LSB.
WR/RDY (Pin 6): WR/RDY is an input when M0DE = V
CC
.
Falling edge of WR switches internal S/H to hold then
starts conversion. WR/RDY is an open drain output (active
pull-down) when M0DE = GND. RDY goes low at start of
conversion and pull-down is turned off when conversion
is complete. Resistive pull-up is usually used in this mode.
MODE (Pin 7): WR-RD when MODE = V
CC
. RD when
M0DE = GND. No internal pull-down.
RD (Pin 8): A Low on RD with CS Low Activates Three-
State Outputs. With MODE = GND and CS low, the falling
edge of RD switches internal S/H to hold and starts
conversion.
INT (Pin 9): Output that goes low when the conversion in
process is complete and goes high after data is read.
GND (Pin 10): Ground Connection.
REF
–
(Pin 11): Low Reference Potential (Analog Ground).
REF
+
(Pin 12): High Reference Potential. V
REF
= Full Scale
= (REF
+
) – (REF
–
).
CS (Pin 13): Chip Select. When high, data outputs are high
impedance and all inputs are ignored.
DB4 to DB7 (Pins 14 to 17): Data Outputs. DB7 = MSB.
OFL (Pin 18): Overflow Output. Goes low when V
IN
> V
REF
.
T
C
(Pin 19): User Adjustable Conversion Time.
V
CC
(Pin 20): Positive Supply. 4.75V ≤ V
CC
≤ 5.25V.
TEST CIRCUITS
RD
RD
CS
C
L
DATA
OUT
V
CC
V
CC
1k
RD
CS
C
L
DATA
OUT
V
CC
V
CC
t
1H
t
r
= 20ns, C
L
= 10pF
t
0H
t
r
= 20ns, C
L
= 10pF
GND
RD
V
CC
GND
GND
V
0H
DATA OUT
V
CC
V
0L
DATA OUT
t
r
t
r
t
1H
t
0H
90%
90%
90%
50%
50%
10%
10%
10%
1099 F01
1k
Figure 1. Three-State Test Circuit