MAX9924–MAX9927
Variable Reluctance Sensor Interfaces with
Differential Input and Adaptive Peak Threshold
_______________________________________________________________________________________ 5
0
5
10
15
20
INPUT OFFSET VOLTAGE DISTRIBUTION
MAX9924 toc01
INPUT OFFSET VOLTAGE (μV)
PERCENTAGE OF UNITS (%)
-2000
-500
0
-1500
-1000
500
1000
1500
3000
2500
2000
V
CM
= 0
BIN SIZE = 250
0
0.1
0.3
0.2
0.4
0.5
-0.5 1.50.5 2.5 3.5 4.5 5.5
INPUT OFFSET VOLTAGE
vs. INPUT COMMON-MODE VOLTAGE
MAX9924 toc02
INPUT COMMON-MODE VOLTAGE (V)
INPUT OFFSET VOLTAGE (mV)
V
OUT
= 2.5V
MAX9925
COMMON-MODE REJECTION RATIO
vs. FREQUENCY
MAX9924 toc03
FREQUENCY (Hz)
CMRR (dB)
10k1k10010
20
40
60
80
100
120
0
1100k
V
BIAS
= V
OUT
= 2.5V
V
CM
= 2V
P-P
CMRR = 20log(A
DM
/A
CM
)
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
MAX9924 toc04
FREQUENCY (Hz)
PSSR (dB)
10k1k10010
-100
-80
-60
-40
-20
0
-110
-90
-70
-50
-30
-10
-120
1 100k
V
RIPPLE
= 100mV
P-P
V
BIAS
= V
OUT
= 2.5V
INPUTS COUPLED TO GND
OPEN LOOP FREQUENCY
RESPONSE
MAX9924 toc05
FREQUENCY (kHz)
GAIN (dB)
0.1
25
50
75
100
125
0
0.001 10
V
CC
= 5V
V
BIAS
= 2.5V
V
OUT
= 2V
P-P
MAX9925
V
OL
AND V
OH
vs. TEMPERATURE
MAX9924 toc06
TEMPERATURE (°C)
V
OL
AND V
OH
(mV)
50 75 100250-25
15
20
40
5
10
25
30
35
0
-50 125
V
CC
- V
OH
V
OL
0
0.2
0.1
0.4
0.3
0.5
0.6
-50 25 50-25 0 75 100 125
INPUT OFFSET VOLTAGE
vs. TEMPERATURE
MAX9924 toc07
TEMPERATURE (°C)
INPUT OFFSET VOLTAGE (mV)
V
CM
= 0
V
OUT
= 2.5V
MAX9925
V
CM
= 2.5V
ADAPTIVE THRESHOLD AND RATIO
vs. SIGNAL LEVEL
MAX9924 toc08
SIGNAL LEVEL (V
P
)
ADAPTIVE THRESHOLD LEVEL (mV)
1.5 2.01.00.5
400
500
900
100
200
300
600
700
800
0
02.5
f
IN
= 1kHz
MAX9924
ADAPTIVE THRESHOLD
vs. TEMPERATURE
MAX9924 toc09
TEMPERATURE (°C)
THRESHOLD (mV)
25 50 75 1000-25
200
250
400
50
100
150
300
350
0
-50 125
V
IN
= 2V
P-P
f
IN
= 1kHz
MAX9924
Typical Operating Characteristics
(V
CC
= 5V, V
GND
= 0V, MAX9925/MAX9927 gain setting = 1V/V. All values are at T
A
= +25°C, unless otherwise noted.)
