Datasheet

LTC2453
6
2453fc
BLOCK DIAGRAM
PIN FUNCTIONS
GND (Pin 1): Ground. Connect to a ground plane through
a low impedance connection.
REF
–
(Pin 2), REF
+
(Pin 3): Differential Reference Input.
The voltage on these pins can have any value between
GND and V
CC
as long as the reference positive input, REF
+
,
remains more positive than the negative reference input,
REF
–
, by at least 2.5V. The differential reference voltage
(V
REF
= REF
+
to REF
–
) sets the full-scale range.
V
CC
(Pin 4): Positive Supply Voltage. Bypass to GND
(Pin 1) with a 10µF capacitor in parallel with a low-series-
inductance 0.1µF capacitor located as close to the part as
possible.
IN
–
(Pin 5), IN
+
(Pin 6): Differential Analog Input.
SCL (Pin 7): Serial Clock Input of the I
2
C Interface. The
LTC2453 can only act as a slave and the SCL pin only ac-
cepts external serial clock. Data is shifted into the SDA pin
on the rising edges of SCL and output through the SDA
pin on the falling edges of SCL.
SDA (Pin 8): Bidirectional Serial Data Line of the I
2
C
Interface. The conversion result is output through the
SDA pin. The pin is high impedance unless the LTC2453
is in the data output mode. While the LTC2453 is in the
data output mode, SDA is an open drain pull down (which
requires an external 1.7k pull-up resistor to V
CC
).
Exposed Pad (Pin 9, DFN Only): Ground. Must be soldered
to PCB ground.
16-BIT ∆∑
A/D CONVERTER
DECIMATING
SINC FILTER
SCL
REF
+
V
CC
REF
–
IN
+
IN
–
GND
SDA
2453 BD
–
16-BIT ∆∑
A/D CONVERTER
I
2
C
INTERFACE
INTERNAL
OSCILLATOR
3 4
7
8
12
6
5