Datasheet

MAX144/MAX145
+2.7V, Low-Power, 2-Channel, 108ksps,
Serial 12-Bit ADCs in 8-Pin µMAX
6 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(V
DD
= +3.0V, V
REF
= 2.5V, 0.1µF at REF, f
SCLK
= 2.17MHz, 16 clocks/conversion cycle (108ksps), CH- = GND for MAX145, T
A
= +25°C,
unless otherwise noted.)
Pin Description
External Reference Voltage Input. Sets the analog voltage range. Bypass with a 100nF capacitor close to
the device.
REF5
Active-Low Chip-Select Input/Active-High Shutdown Input. Pulling CS/SHDN high puts the device into
shutdown with a maximum current of 5µA.
CS/SHDN
6
Serial Data Output. Data changes state at SCLK’s falling edge. High impedance when CS/SHDN
is high.
DOUT7
Serial Clock Input. DOUT changes on the falling edge of SCLK.SCLK8
Analog and Digital GroundGND4
Analog Input: MAX144 = single-ended (CH1); MAX145 = differential (CH-)CH1 (CH-)3
PIN
Analog Input: MAX144 = single-ended (CH0); MAX145 = differential (CH+)CH0 (CH+)2
Positive Supply Voltage, +2.7V to +5.25VV
DD
1
FUNCTIONNAME
-0.20
-0.10
-0.15
0
-0.05
0.05
0.10
0.15
0.20
0 1024 2048 3072 4096
INTEGRAL NONLINEARITY
vs. OUTPUT CODE
MAX144/5-10
OUTPUT CODE
INL (LSB)
0
0.1
0.2
0.3
0.4
0.5
2.5 3.53.0 4.0 4.5 5.0 5.5
INTEGRAL NONLINEARITY
vs. SUPPLY VOLTAGE
MAX144/5-11
V
DD
(V)
INL (LSB)
0
0.1
0.2
0.3
0.4
0.5
INTEGRAL NONLINEARITY
vs. TEMPERATURE
MAX144/5-12
INL (LSB)
TEMPERATURE (°C)
-60 -10 15-35 40 65 90 115 140
-140
-100
-120
-60
-80
-40
-20
0
20
02754
FFT PLOT
MAX144/5-13
FREQUENCY (kHz)
AMPLITUDE (dB)
V
DD
= +2.7V
f
IN
= 10kHz
f
SAMPLE
= 108ksps
12.0
11.0
1 10 100
EFFECTIVE NUMBER OF BITS
vs. FREQUENCY
11.2
MAX144/5-14
FREQUENCY (kHz)
EFFECTIVE NUMBER OF BITS
11.4
11.6
11.8
V
DD
= +2.7V