MAX186 Maxim, MAX186 Datasheet - Page 11

• Manufacturer Part Number: MAX186
• Description: Low-Power / 8-Channel / Serial 12-Bit ADCs
• Manufacturer: Maxim

Table 3. Channel Selection in Single-Ended Mode (SGL/
Table 4. Channel Selection in Differential Mode (SGL/
SEL2
SEL2
2) Use a general-purpose I/O line on the CPU to pull
3) Transmit TB1 and simultaneously receive a byte
4) Transmit a byte of all zeros ($00 HEX) and simulta-
5) Transmit a byte of all zeros ($00 HEX) and simulta-
6) Pull CS on the MAX186/MAX188 high.
0
1
0
1
0
1
0
1
0
0
0
0
1
1
1
1
CS on the MAX186/MAX188 low.
and call it RB1. Ignore RB1.
neously receive byte RB2.
neously receive byte RB3.
SEL1
SEL1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
______________________________________________________________________________________
SEL0
SEL0
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
CH0
CH0
+
+
–
CH1
CH1
+
+
–
CH2
+
CH2
+
–
DIFF
DIFF
CH3
Figure 6 shows the timing for this sequence. Bytes RB2
and RB3 will contain the result of the conversion
padded with one leading zero and three trailing zeros.
The total conversion time is a function of the serial
clock frequency and the amount of dead time between
8-bit transfers. Make sure that the total conversion time
does not exceed 120µs, to avoid excessive T/H droop.
In unipolar input mode, the output is straight binary
(see Figure 15). For bipolar inputs, the output is
twos-complement (see Figure 16). Data is clocked out
at the falling edge of SCLK in MSB-first format.
Low-Power, 8-Channel,
+
= 0)
CH3
= 1)
+
–
CH4
Serial 12-Bit ADCs
+
CH4
+
–
CH5
+
CH5
+
–
CH6
+
CH6
+
–
CH7
Digital Output
+
CH7
AGND
+
–
–
–
–
–
–
–
–
–
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