Datasheet

2.5V Max
V
CM
+ 0.5V
V
CM
V
CM
- 0.5V
0V Min
ADC10040
www.ti.com SNAS224M –JULY 2003–REVISED APRIL 2013
FUNCTIONAL DESCRIPTION
The ADC10040 uses a pipeline architecture and has error correction circuitry to help ensure maximum
performance. Differential analog input signals are digitized to 10 bits. In differential mode , each analog input
signal should have a peak-to-peak voltage equal to 1.0V, 0.75V or 0.5V, depending on the state of the IRS pin
(pin 5), and be centered around V
CM
and be 180° out of phase with each other. If single ended operation is
desired, V
IN
- may be tied to the V
COM
pin (pin 4). A single ended input signal may then be applied to V
IN
+, and
should have an average value in the range of V
CM
. The signal amplitude should be 2.0V, 1.5V or 1.0V peak-to-
peak, depending on the state or the IRS pin (pin 5).
APPLICATIONS INFORMATION
ANALOG INPUTS
The ADC10040 has two analog signal inputs, V
IN
+ and V
IN
−. These two pins form a differential input pair. There
is one common mode pin V
COM
that may be used to set the common mode input voltage.
REFERENCE PINS
The ADC10040 is designed to operate with an internal or external 1.2V reference. The internal 1.2V reference is
the defualt condition. If an external voltage is applied to the V
REF
pin, then that voltage is used for the reference.
The V
REF
pin should be bypassed to ground with a 0.1 µF capacitor placed close to the pin. Do not load this pin
when using the internal reference.
The voltages at V
COM
, V
REFT
, and V
REFB
are derived from the reference voltage. These pins are made available
for bypass purposes only. These pins should each be bypassed to ground with a 0.1 µF capacitor placed close
to the pin. It is very important that all grounds associated with the reference voltage and the input signal make
connection to the analog ground plane at a single point to minimize the effects of noise currents in the ground
path. DO NOT LOAD these pins.
V
COM
PIN
This pin supplies a voltage for possible use to set the common mode input voltage. This pin may also be
connected to V
IN
-, so that V
IN
+ may be used as a single ended input. These pins should be bypassed with at
least a 0.1uF capacitor. Do not load this pin.
SIGNAL INPUTS
The signal inputs are V
IN
+ and V
IN
−. The input signal amplitude is defined as V
IN
+ − V
IN
− and is represented
schematically in Figure 38:
Figure 38. Input Voltage Waveforms for a 2V
P-P
differential Input
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