Datasheet

MAX7490/MAX7491
Dual Universal Switched-Capacitor Filters
_______________________________________________________________________________________ 7
-20
-120
1k 10k
MAX7490
THD + NOISE vs. FREQUENCY
MAX7490-13
INPUT FREQUENCY (Hz)
THD + NOISE (dB)
-30
-40
-50
-60
-70
-80
-90
-100
-110
B
A
A = MODE 1
B = MODE 3
-90
-80
-70
-60
-50
-40
-30
-20
-10
01.00.5 1.5 2.0 2.5 3.0
MAX7491
THD + NOISE vs. INPUT VOLTAGE
MAX7490-14
INPUT VOLTAGE (Vp-p)
THD + NOISE (dB)
B
A
A = MODE 1
B = MODE 3
-90
-80
-70
-60
-50
-40
-30
-20
-10
012345
MAX7490
THD + NOISE vs. INPUT VOLTAGE
MAX7490-15
INPUT VOLTAGE (Vp-p)
THD + NOISE (dB)
B
A
A = MODE 1
B = MODE 3
2.0
3.0
2.5
3.5
4.0
4.5
5.0
084121620
OUTPUT VOLTAGE SWING
vs. LOAD RESISTANCE
MAX7490-16
R
LOAD
(k
Ω
) TO COM
OUTPUT SWING (Vp-p)
V
DD
= 5V
V
DD
= 3V
0
500
1500
1000
2000
2500
0400200 600 800 1000
INTERNAL OSCILLATOR PERIOD
vs. SMALL CAPACITANCE
MAX7490-17
CAPACITANCE (pF)
INTERNAL OSCILLATOR FREQUENCY (kHz)
V
DD
= 3V
V
DD
= 5V
0
20
40
60
80
100
120
140
160
132 4567
INTERNAL OSCILLATOR PERIOD
vs. LARGE CAPACITANCE
MAX7490-18
CAPACITANCE (nF)
INTERNAL OSCILLATOR FREQUENCY (kHz)
V
DD
= 5V
V
DD
= 3V
126
128
127
130
129
132
131
133
3.0 4.03.5 4.5 5.0 5.5
INTERNAL OSCILLATOR FREQUENCY
vs. SUPPLY VOLTAGE
MAX7490-19
V
DD
(V)
INTERNAL OSCILLATOR FREQUENCY (kHz)
C
OSC
= 1000pF
124
130
128
126
132
134
136
138
140
142
144
-40 10-15 35 60 85
INTERNAL OSCILLATOR FREQUENCY
vs. TEMPERATURE
MAX7490-20
TEMPERATURE (°C)
INTERNAL OSCILLATOR FREQUENCY (kHz)
V
DD
= 3V
V
DD
= 5V
C
OSC
= 1000pF
Typical Operating Characteristics (continued)
(V
DD
= +5V for MAX7490, V
DD
= +3V for MAX7491, f
CLK
= 625kHz, V
SHDN
= V
EXTCLK
= V
DD
, COM = V
DD
/2, Mode 1, R3 = R1 = 50kΩ,
R2 = 10kΩ, Q = 5, T
A
= +25°C, unless otherwise noted.)