MAX1204 Datasheet, PDF (11/24 Pages) Maxim Integrated Products – 5v, 8-cHANNEL, sERIAL, 10-bIT adc WITH 3v dIGITAL iNTERFACE

5V, 8-Channel, Serial, 10-Bit ADC
with 3V Digital Interface
Table 2. Control-Byte Format
Bit 7
(MSB)
START
Bit 6
SEL 2
Bit 5
SEL 1
Bit 4
SEL 0
Bit 3
UNI/BIP
Bit 2
SGL/DIF
Bit 1
PD1
Bit 0
(LSB)
PD0
Bit
7 (MSB)
6
5
4
3
2
1
0 (LSB)
Name
START
SEL2
SEL1
SEL0
UNI/BIP
SGL/DIF
PD1
PD0
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 is used for the conversion
(Tables 3 and 4).
1 = unipolar, 0 = bipolar. Selects unipolar or bipolar conversion mode. In unipolar mode, an
analog input signal from 0V to V_REF can be converted; in bipolar mode, the signal can range
from -V_REF / 2 to +V_REF / 2.
1 = single ended, 0 = differential. Selects single-ended or differential conversions. In single-
ended mode, input signal voltages are referred to GND. In differential mode, the voltage dif-
ference between two channels is measured. (Tables 3 and 4.)
Selects clock and power-down modes.
PD1
PD0
Mode
0
0
Full power-down (I_DD = 2µA, internal reference)
0
1
Fast power-down (I_DD = 30µA, internal reference)
1
0
Internal clock mode
1
1
External clock mode
Table 3. Channel Selection in Single-Ended Mode (SGL/DIF = 1)
SEL2 SEL1 SEL0 CH0
CH1
CH2
CH3
CH4
CH5
CH6
0
0
0
+
1
0
0
+
0
0
1
+
1
0
1
+
0
1
0
+
1
1
0
+
0
1
1
+
1
1
1
Table 4. Channel Selection in Differential Mode (SGL/DIF = 0)
SEL2
SEL1
SEL0
CH0
CH1
CH2
CH3
CH4
CH5
0
0
0
+
–
0
0
1
+
–
0
1
0
+
–
0
1
1
1
0
0
–
+
1
0
1
–
+
1
1
0
–
+
1
1
1
CH7
+
CH6
+
–
GND
–
–
–
–
–
–
–
–
CH7
–
+
______________________________________________________________________________________ 11