Datasheet

4 Maxim Integrated
Digitally-Programmed, Dual
2nd-Order Continuous Lowpass Filter
MAX270/MAX271
TIMING CHARACTERISTICS (Figure 2)
(V+ = +5V, V- = -5V; T
A
= +25NC, unless otherwise noted.)
Note 11: All input control signals specified with t
r
= t
f
= 5ns (10% to 90% of +5V) and timed from a +1.6V voltage level.
Typical Operating Characteristics
FILTER GAIN vs. FREQUENCY
MAX270 toc01
f
IN
(Hz)
GAIN (dB)
100k10k
-60
-40
-20
0
-80
1k 1M
V+ = +5V
V- = -5V
f
C
CODE = 127 (25kHz TYP)
T
A
= +25˚C
FILTER GAIN vs. FREQUENCY
(NORMALIZED TO CUTOFF FREQUENCY)
MAX270 toc02
f
IN/
f
C
GAIN (dB)
101.0
-60
-40
-20
0
-80
0.1 100
V+ = +5V
V- = -5V
f
C
CODE = 0-127 (1-25kHz TYP)
T
A
= +25˚C
MAX270 toc03
f
IN/
f
C
GAIN (dB)
10010
-2
-1
0
0.5
-3
11
k
V+ = +5V
V- = -5V
f
C
CODE = 0 (1kHz TYP)
T
A
= +125˚C
T
A
= +25˚C
T
A
= -55˚C
PASSBAND FILTER GAIN
vs. FREQUENCY
PASSBAND FILTER GAIN
vs. FREQUENCY
MAX270 toc04
f
IN
(Hz)
GAIN (dB)
1k 10k100
-2
-1
0
0.5
-3
25 25k
V+ = +5V
V- = -5V
f
C
CODE = 127 (25kHz TYP)
T
A
= +125˚C
T
A
= +25˚C
T
A
= -55˚C
MAX270 toc05
f
IN/
f
C
GAIN (dB)
0.10.01
-2
-1
0
+0.5
-3
0.001 1.0
PASSBAND FILTER GAIN vs. FREQUENCY
(NORMALIZED TO CUTOFF FREQUENCY)
V+ = +5V
V- = -5V
f
C
CODE = 0-127 (1-25kHz TYP)
T
A
= +25˚C
MAX270 toc06
f
IN/
f
C
PHASE SHIFT (DEGREES)
1.00.1
-45
-90
-135
-180
0
0.01 10
FILTER PHASE SHIFT vs. FREQUENCY
(NORMALIZED TO CUTOFF FREQUENCY)
V+ = +5V
V- = -5V
f
C
CODE = 0-127
(1-25kHz TYP)
T
A
= +25˚C
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
CS to WR Setup
t
WS
0 ns
CS to WR Hold
t
WH
0 ns
WR Pulse Width
t
SV
100 ns
Address-Setup Time t
AS
30 ns
Address-Hold Time t
AH
10 ns
Data-Setup Time t
DS
30 ns
Data-Hold time t
DH
10 ns