Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V+ = +5V, V- = -5V; T
A
= +25NC, unless otherwise noted.)
PARAMETER
FILTER CHARACTERISTICS
Operating Frequency Range
Programmed Cutoff Frequency (f
C
)
Range
Programmed Cutoff Frequency
Error
f
C
code = 53 (2.536kHz typ)
f
C
code = 127 (25kHz typ)
f
C
code = 0 (1kHz typ),
T
A
= T
MIN
to T
MAX
f
C
code = 127 (25kHz typ),
T
A
= T
MIN
to T
MAX
f
C
code = 0 (1kHz typ)
f
C
code = 127 (25kHz typ)
f
C
code = 0
(1kHz typ)
f
C
code = 127
(25kHz typ)
0.15
12
FV
RMS
38
f
IN
= 1kHz
f
IN
= 8kHz
f
IN
= 25kHz
f
IN
= 200kHz
-6
-34
0.15
dB
-3.6
(Note 1)
2
1 to 25
Q2.9
Q9.5
-2.4
-33
-0.5
dB
MHz
kHz
%
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Filter Gain
Maximum Gain (Peaking)
Wideband Noise
50Hz to 50kHz bandwidth
DC CHARACTERISTICS
DC Output Signal Swing
OUTA, OUTB, OP OUT (MAX270)
OUTA, OUTB, T/H OUT (MAX271)
Offset Voltage at Outputs
OUTA, OUTB, OP OUT (MAX270)
OUTA, OUTB, T/H OUT (MAX271)
DC Input Leakage Current
INA, INB (MAX270)
INA, INB (MAX271)
T
A
= T
MIN
to T
MAX
R
LOAD
= 5kI, T
A
= T
MIN
to T
MAX
-3
+3
V
-2
+2
mV
-1
+1
FA
2
Maxim Integrated
MAX270/MAX271
Digitally-Programmed, Dual
2nd-Order Continuous Lowpass Filter
ELECTRICAL CHARACTERISTICS (continued)
(V+ = +5V, V- = -5V; T
A
= +25NC, unless otherwise noted.)
PARAMETER
SYMBOL
DYNAMIC FILTER CHARACTERISTICS (MAX270)
Total Harmonic Distortion
Signal Noise Plus Distortion
Spurious-Free Dynamic Range
Slew Rate
Bandwidth
TRACK AND HOLD (MAX271)
Hold Settling Time
Acquisition Time
Hold Step
Droop Rate
Offset Voltage at T/H OUT
T/H OUT Disabled Output Leakage
Current
Total Harmonic Distortion
Spurious-Free Dynamic Range
DIGITAL INPUTS
Digital Input High Voltage
Digital Input Low Voltage
Digital Input Current
POWER REQUIREMENTS
Supply Voltage Range
Supply Current
Shutdown Supply Current
Power-Supply Rejection Ratio at
1kHz
Note 1:
Note 2:
Note 3:
Note 4:
Note 5:
Note 6:
Note 7:
Note 8:
PSRR
T
A
= T
MIN
to T
MAX
(Note 9)
T
A
= T
MIN
to T
MAX
(Note 10)
f
C
code = 0 (1kHz typ), V
+
= 5V
DC
+
10mV
P-P
at 1kHz
30
Q2.375
to
Q8
6.5
15
V
mA
FA
dB
T
A
= T
MIN
to T
MAX
, digital input held at
Q5V,
includes MODE (MAX271)(Note 8)
-1
T
A
= T
MIN
to T
MAX
(Note 8)
2.4
0.8
+1
V
FA
THD
SFDR
T
A
= T
MIN
to T
MAX
Includes filter offset
T
A
= T
MIN
to T
MAX
, V
T/H
= 0V (Track Mode)
f
C
code = 44 (2.01kHz typ), V
IN
= 3.5V
P-P
at
390.625Hz, sampling rate = 50kHz
(Notes 2, 6, 7)
-6
-10
To 0.1% (Note 4)
To 0.1% (Note 5)
500
1.8
1
30
+6
+10
-70
70
dB
ns
Fs
mV
FV/Fs
mV
FA
THD
SINAD
SFDR
f
C
code = 44 (2.01kHz typ), V
IN
= 3.5V
P-P
at
390.625Hz (Notes 2 and 3)
-70
73
70
1.2
2
V/Fs
MHz
dB
CONDITIONS
MIN
TYP
MAX
UNITS
UNCOMMITTED AMPLIFIER (MAX270)
All internal amplifiers limited to 2MHz bandwidth.
Only filter A tested for these parameters.
Spurious-Free Dynamic Range is the ratio of the fundamental to the largest of any harmonic or noise spur in dB.
Includes T/H propagation delays. With 5kω, parallel 100pF load.
±2V input step settling 0.1% with 5kω parallel 100pF load.
T/H
pin toggled at sampling rate, 50% duty cycle.
THD and SFDR specifications for T/H include contributions from filter.
Digital pins include
SHDN, WR, CS,
A0, D0–D6 (MAX270) and
SHDN,
T/H, A/B,
WR,
T/H EN,
CS,
A0, A1, D0–D6,
T/H
(MAX271).
Note 9:
Input of uncommitted op amp disconnected with a 5kω feedback resistor from input to output.
Note 10:
WR, CS,
A0, D0–D6 held at +5V; V
SHDN
= 0V (MAX270).
WR, CS,
A0, A1, D0–D6,
T/H,
T/H, A/B, T/H, MODE held at
+5V; V
SHDN
= 0V (MAX271).
Maxim Integrated
3
MAX270/MAX271
Digitally-Programmed, Dual
2nd-Order Continuous Lowpass Filter
TIMING CHARACTERISTICS (Figure 2)
(V+ = +5V, V- = -5V; T
A
= +25NC, unless otherwise noted.)
PARAMETER
CS
to
WR
Setup
CS
to
WR
Hold
WR
Pulse Width
Address-Setup Time
Address-Hold Time
Data-Setup Time
Data-Hold time
SYMBOL
t
WS
t
WH
t
SV
t
AS
t
AH
t
DS
t
DH
100
30
10
30
10
CONDITIONS
MIN
TYP
MAX
0
0
UNITS
ns
ns
ns
ns
ns
ns
ns
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.