ADC10662CIWMX/NOPB National Semiconductor, ADC10662CIWMX/NOPB Datasheet - Page 4

• Manufacturer Part Number: ADC10662CIWMX/NOPB
• Manufacturer: National Semiconductor

Pin Descriptions
Pin Function
DV
INT
S/H
RD
CS
S0, S1
V
V
V
GND, AGND,
DGND
DB0–DB9
SPEEDADJ
REF−
IN0
IN2
CC
, V
, V
, AV
, V
IN1
IN3
REF+
,
CC
Description
Digital and analog positive supply voltage inputs. Connect both to the same voltage source, but
bypass separately with a 0.1 µF ceramic capacitor in parallel with a 10 µF tantalum capacitor to
ground at each pin.
Active low interrupt output. INT goes low at the end of each conversion, and returns high
following the rising edge of RD .
Sample/Hold control input. When this pin is forced low (and CS is low), the analog input signal to
be sampled and initiates a new conversion.
Active low Read control input. When this RD and CS are low, any data present in the output
registers will be placed on the data bus.
Active low Chip Select control input. When low, this pin enables the RD and S/H pins.
These pins select the analog input that will be connected to the A/D during the conversion. The
input is selected based on the state of S0 and S1 when S/H makes its High-to-Low transition
(See the Timing Diagrams). The ADC10664 includes both S0 and S1. The ADC10662 includes
just S0.
Reference voltage inputs. They may be placed at any voltage between GND and V
must be greater than V
an input voltage equal to (V
Analog input pins. The ADC10662 has two inputs (V
inputs (V
best accuracy and conversion speed. For accurate conversions, no input pin (even one that is
not selected) should be driven more than 50 mV above V
Power supply ground pins. The ADC10662 and ADC10664 have separate analog and digital
ground pins (AGND and DGND) for separate bypassing of the analog and digital supplies. The
ground pins should be connected to a stable, noise-free system ground. Both pins should be
returned to the same potential.
TRI-STATE output pins.
By connecting a resistor between this pin and ground, the conversion time can be reduced. The
specifications listed in the table of Electrical Characteristics apply for a speed adjust resistor
(R
the table of Electrical Characteristics.
SA
) equal to 14.0 kΩ (Mode 1) or 8.26 kΩ (Mode 2). See the Typical Performance Curves and
IN0
, V
IN1
, V
IN2
REF−
and V
. An input voltage equal to V
REF+
IN3
). The impedance of the source should be less than 500Ω for
− 1 LSB) produces an output code of 1023.
3
IN0
and V
REF−
CC
or 50 mV below ground.
produces an output code of 0, and
IN1
) and the ADC10664 has four
CC
, but V
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REF+