MAX146 Maxim, MAX146 Datasheet - Page 11

• Manufacturer Part Number: MAX146
• Description: +2.7Low-Power / 8-Channel / Serial 12-Bit ADCs
• Manufacturer: Maxim

Table 1. Control-Byte Format
Table 2. Channel Selection in Single-Ended Mode
Table 3. Channel Selection in Differential Mode (SGL/DIF = 0)
SEL2
SEL2
BIT 7
(MSB)
START
BIT
7(MSB)
6
5
4
3
2
1
0(LSB)
0
1
0
1
0
1
0
1
0
0
0
0
1
1
1
1
SEL1
SEL1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
NAME
START
SEL2
SEL1
SEL0
UNI/BIP
SGL/DIF
PD1
PD0
BIT 6
SEL2
______________________________________________________________________________________
SEL0
SEL0
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
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).
1 = unipolar, 0 = bipolar. Selects unipolar or bipolar conversion mode. In unipolar mode, an
analog input signal from 0V to VREF can be converted; in bipolar mode, the signal can range
from -VREF/2 to +VREF/2.
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).
Selects clock and power-down modes.
PD1
0
0
1
1
BIT 5
SEL1
CH0
CH0
+
+
–
PD0
0
1
0
1
CH1
CH1
+
+
–
+2.7V, Low-Power, 8-Channel,
BIT 4
SEL0
Mode
Full power-down
Fast power-down (MAX146 only)
Internal clock mode
External clock mode
CH2
+
CH2
+
–
CH3
+
BIT 3
UNI/BIP
CH3
+
–
(SGL/DIF = 1)
CH4
Serial 12-Bit ADCs
+
CH4
+
–
BIT 2
SGL/DIF
CH5
+
CH5
+
–
CH6
+
BIT 1
PD1
CH6
+
–
CH7
+
CH7
+
BIT 0
(LSB)
PD0
–
COM
–
–
–
–
–
–
–
–
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