adc12032 National Semiconductor Corporation, adc12032 Datasheet - Page 30

• Manufacturer Part Number: adc12032
• Description: Self-calibrating 12-bit Plus Sign Serial I/o A/d Converters With Mux And Sample/hold
• Manufacturer: National Semiconductor Corporation

www.national.com
Application Hints
CH0, CH2, CH4, and CH6 can be assigned to the MUX-
OUT1 pin in the differential configuration, while CH1, CH3,
CH5, and CH7 can be assigned to the MUXOUT2 pin. In the
differential configuration, the analog inputs are paired as
follows: CH0 with CH1, CH2 with CH3, CH4 with CH5 and
CH6 with CH7. The A/DIN1 and A/DIN2 pins can be as-
signed positive or negative polarity.
A/DIN1 and A/DIN2 can be assigned as the + or − input
The Multiplexer assignment tables for the ADC12030,2,4,8
( Tables 2, 3, 4 ) summarize the aforementioned functions for
the different versions of A/Ds.
2.1 Biasing for Various Multiplexer Configurations
Figure 11 is an example of biasing the device for
single-ended operation. The sign bit is always low. The
digital output range is 0 0000 0000 0000 to 0 1111 1111 1111.
One LSB is equal to 1 mV (4.1V/4096 LSBs).
Configuration
Differential
(Continued)
01135440
FIGURE 11. Single-Ended Biasing
FIGURE 10.
30
A/DIN1 is + input
A/DIN2 is − input
With the single-ended multiplexer configuration CH0 through
CH7 can be assigned to the MUXOUT1 pin. The COM pin is
always assigned to the MUXOUT2 pin. A/DIN1 is assigned
as the positve input; A/DIN2 is assigned as the negative
input. (See Figure 10 ).
Configuration
Single-Ended
01135441
01135446