Rainbow Electronics MAX188 - Manual (Page 6)

Reference Voltage for analog-to-digital conversion. Also, Output of the Reference Buffer Amplifier
(4.096V in the MAX186, 1.638 x REFADJ in the MAX188). Add a 4.7µF capacitor to ground when
using external compensation mode. Also functions as an input when used with a precision external
reference.
MAX186/MAX188
Low-Power, 8-Channel,
Serial 12-Bit ADCs
6 ________________________________________________________________________________________________
__________________________________________Typical Operating Characteristics
0.30
-0.05
-60 140
POWER-SUPPLY REJECTION
vs. TEMPERATURE
0.00
0.25
TEMPERATURE (°C)
PSR (LSBs)
60
0.10
0.05
-40 20 100
0.15
0.20
-20 0 40 80 120
V
DD
= +5V ±5%
V
SS
= 0V or -5V
2.456
INTERNAL REFERENCE VOLTAGE
vs. TEMPERATURE
2.452
2.455
TEMPERATURE (°C)
VREFADJ (V)
2.454
2.453
-40 -20 0 20 40 60 80 100 120
0.16
0
-60 -20 60 140
CHANNEL-TO-CHANNEL OFFSET MATCHING
vs. TEMPERATURE
0.02
0.12
TEMPERATURE (°C)
OFFSET MATCHING (LSBs)
20 100
0.10
0.04
-40 0 40 80 120
0.14
0.08
0.06
20
-140
0 66.5kHz
MAX186/MAX188 FFT PLOT – 133kHz
-120
0
-80
-100
-40
-20
-60
ft = 10kHz
fs = 133kHz
33.25kHz
AMPLITUDE (dB)
FREQUENCY
ft = 10kHz
f
s
= 133kHz
T
A
= +25°C
PIN NAME FUNCTION
1-8 CH0-CH7 Sampling Analog Inputs
9 V
SS Negative Supply Voltage. Tie to -5V ±5% or AGND
10 SHDN
11 VREF
Three-Level Shutdown Input. Pulling SHDN low shuts the MAX186/MAX188 down to 10µA (max)
supply current, otherwise the MAX186/MAX188 are fully operational. Pulling SHDN high puts the ref-
erence-buffer amplifier in internal compensation mode. Letting SHDN float puts the reference-buffer
amplifier in external compensation mode.
_____________________________________________________________Pin Description