ADC1038CIN National Semiconductor, ADC1038CIN Datasheet - Page 12

• Manufacturer Part Number: ADC1038CIN
• Description: IC ADC 10BIT SERIAL I/O 20DIP
• Manufacturer: National Semiconductor

Specifications of ADC1038CIN

• Number Of Bits: 10
• Data Interface: MICROWIRE™, Serial
• Number Of Converters: 1
• Power Dissipation (max): 20mW
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Through Hole
• Package / Case: 20-DIP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: *ADC1038CIN

3 0 Analog Considerations
3 3 REFERENCE AND INPUT
The two V
tial and define the zero to full-scale input range of the A to D
converter This allows the designer to easily vary the span
of the analog input since this range will be equivalent to the
voltage difference between V
ing V
sensitivity of the converter can be increased (i e if V
2V then 1 LSB
Power Supply Bypassing
External Reference 2 5V Full Scale
REF
(V
REF
REF
inputs of the ADC1031 4 8 are fully differen-
e
e
1 95 mV) The input reference arrange-
V
REF
a b
TL H 10556– 20
REF
V
REF
a
b
and V
) to less than 5V the
REF
(Continued)
FIGURE 3 Analog Input Options
b
TL H 10556– 23
Power Supply as Reference
By reduc-
REF
e
12
ment also facilitates ratiometric operation and in many
cases the chip power supply can be used for transducer
power as well as the V
This reference flexibility lets the input span not only be var-
ied but also offset from zero The voltage at V
input level which produces a digital output of all zeros
Though V
allows nearly differential-input capability for many measure-
ment applications Figure 3 shows some of the configura-
tions that are possible
The ADC1031 has no V
GND
TL H 10556– 21
IN
is not itself differential the reference design
ground
Current path must still exist from V
REF
REF
Input Not Referred to GND
b
source
pin V
REF
b
is internally tied to
REF
TL H 10556 – 22
TL H 10556 – 24
b
sets the
IN
(
b
)
to