ltc2484 Linear Technology Corporation, ltc2484 Datasheet - Page 11

• Manufacturer Part Number: ltc2484
• Description: 24-bit Delta Sigma Adc With Easy Drive Input Current Cancellation
• Manufacturer: Linear Technology Corporation

PI FU CTIO S
as CS is HIGH. A LOW-to-HIGH transition on CS during the
Data Output transfer aborts the data transfer and starts a
new conversion.
SDO (Pin 7): Three-State Digital Output. During the Data
Output period, this pin is used as the serial data output.
When the chip select CS is HIGH (CS = V
is in a high impedance state. During the Conversion and
Sleep periods, this pin is used as the conversion status
output. The conversion status can be observed by pulling
CS LOW.
GND (Pin 8): Ground. Shared pin for analog ground,
digital ground and reference ground. Should be connected
directly to a ground plane through a minimum impedance.
SCK (Pin 9): Bidirectional Digital Clock Pin. In Internal
Serial Clock Operation mode, SCK is used as the digital
output for the internal serial interface clock during the Data
FU CTIO AL BLOCK DIAGRA
TEST CIRCUITS
U
U
U
U
SDO
U
Hi-Z TO V
V
V
1.69k
OL
OH
3
4
5
TO V
TO Hi-Z
V
IN
IN
REF
+
–
OH
OH
SENSOR
TEMP
C
LOAD
2484 TC01
= 20pF
MUX
CC
), the SDO pin
W
IN
IN
+
–
REF
3RD ORDER
8
∆Σ ADC
GND
–
REF
AUTOCALIBRATION
AND CONTROL
Input/Output period. In External Serial Clock Operation
mode, SCK is used as the digital input for the external
serial interface clock during the Data Output period. A weak
internal pull-up is automatically activated in Internal Serial
Clock Operation mode. The Serial Clock Operation mode is
determined by the logic level applied to the SCK pin at
power up or during the most recent falling edge of CS.
F
controls the conversion clock. When F
GND the converter uses its internal oscillator running at
307.2kHz. The conversion clock may also be overridden
by driving the F
change the output rate or the digital filter rejection null.
Exposed Pad (Pin 11): This pin is ground and should be
soldered to the PCB, GND plane. For prototyping purposes
this pin may remain floating.
+
O
(Pin 10): Frequency Control Pin. Digital input that
V
CC
2
INTERFACE
SERIAL
O
OSCILLATOR
INTERNAL
pin with an external clock in order to
SDO
Hi-Z TO V
V
V
OH
OL
V
TO Hi-Z
SCK
SD0
TO V
CC
SDI
CS
1.69k
2484 FB
C
OL
OL
LOAD
1
9
7
6
2484 TC02
= 20pF
O
LTC2484
is connected to
11
2484fa