MAX1280 Datasheet, PDF (14/24 Pages) Maxim Integrated Products – 400ksps/300ksps, Single-Supply, Low-Power, 8-Channel, Serial 12-Bit ADCs with Internal Reference

400ksps/300ksps, Single-Supply, Low-Power, 8-Channel,
Serial 12-Bit ADCs with Internal Reference
Table 1. Control-Byte Format
BIT 7
(MSB)
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
(LSB)
START
SEL2
SEL1
SEL0
UNI/BIP
SGL/DIF
PD1
PD0
BIT
7 (MSB)
6
5
4
NAME
START
SEL2
SEL1
SEL0
DESCRIPTION
The first logic “1” bit after CS goes low defines the beginning of the control byte.
These three bits select which of the eight channels are used for the conversion (Tables 2 and 3).
3
UNI/BIP
1 = unipolar, 0 = bipolar. Selects unipolar or bipolar conversion mode. In unipolar mode, an
analog input signal from 0 to V_REF can be converted; in bipolar mode, the differential signal can
range from -V_REF/2 to +V_REF/2.
2
SGL/DIF
1 = single ended, 0 = differential. Selects single-ended or differential conversions. In single-
ended mode, input signal voltages are referred to COM. In differential mode, the voltage
difference between two channels is measured (Tables 2 and 3).
1
PD1
0 (LSB)
PD0
Select operating mode.
PD1
PD0
Mode
0
0
Full power-down
0
1
Fast power-down
1
0
Reduced Power
1
1
Normal Operation
Table 2. Channel Selection in Single-Ended Mode (SGL/DIF = 1)
SEL2
0
0
0
0
1
1
1
1
SEL1
0
0
1
1
0
0
1
1
SEL0
0
1
0
1
0
1
0
1
CH0
+
CH1
+
CH2
+
CH3
CH4
+
+
CH5
+
CH6
+
CH7
+
COM
–
–
–
–
–
–
–
–
Table 3. Channel Selection in Psuedo-Differential Mode (SGL/DIF = 0)
SEL2
0
0
0
0
1
1
1
1
SEL1
0
0
1
1
0
0
1
1
SEL0
0
1
0
1
0
1
0
1
CH0
+
–
CH1
–
+
CH2
+
–
CH3
–
+
CH4
+
–
CH5
–
+
CH6
CH7
+
–
–
+
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