19-4764; Rev 2; 6/99
8th-Order, Lowpass, Elliptic,
Switched-Capacitor Filters
General Description
The MAX7400/MAX7403/MAX7404/MAX7407 8th-order,
lowpass, elliptic, switched-capacitor filters (SCFs) oper-
ate from a single +5V (MAX7400/MAX7403) or +3V
(MAX7404/MAX7407) supply. These devices draw 2mA
of supply current and allow corner frequencies from
1Hz to 10kHz, making them ideal for low-power anti-
aliasing and post-DAC filtering applications. They fea-
ture a shutdown mode that reduces the supply current
to 0.2µA.
Two clocking options are available: self-clocking
(through the use of an external capacitor) or external
clocking for tighter cutoff-frequency control. In addition,
an offset adjustment pin (OS) allows for the adjustment
of the DC output level.
The MAX7400/MAX7404 provide 82dB of stopband
rejection and a sharp rolloff with a transition ratio of 1.5.
The MAX7403/MAX7407 provide a sharper rolloff with a
transition ratio of 1.2, while still delivering 60dB of stop-
band rejection. The fixed response of these devices
simplifies the design task to corner-frequency selection
by setting a clock frequency. The MAX7400/
MAX7403/MAX7404/MAX7407 are available in 8-pin SO
and DIP packages.
o
8th-Order Lowpass Elliptic Filter
o
Low Noise and Distortion
-82dB THD + Noise (MAX7400)
o
Clock-Tunable Corner Frequency (1Hz to 10kHz)
o
100:1 Clock-to-Corner Ratio
o
Single-Supply Operation
+5V (MAX7400/MAX7403)
+3V (MAX7404/MAX7407)
o
Low Power
2mA (Operating Mode)
0.2µA (Shutdown Mode)
o
Available in 8-Pin SO and DIP Packages
o
Low Output Offset: ±5mV
Features
MAX7400/MAX7403/MAX7404/MAX7407
Ordering Information
PART
MAX7400CSA
MAX7400CPA
MAX7400ESA
MAX7400EPA
TEMP. RANGE
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
8 SO
8 Plastic DIP
8 SO
8 Plastic DIP
Applications
ADC Anti-Aliasing
Post-DAC Filtering
CT2 Base Stations
Speech Processing
Air-Bag Electronics
Ordering Information continued at end of data sheet.
Selector Guide
PART
MAX7400
FILTER RESPONSE
Elliptic (r = 1.5)
Elliptic (r = 1.2)
Elliptic (r = 1.5)
Elliptic (r = 1.2)
OPERATING
VOLTAGE (V)
+5
+5
+3
+3
Typical Operating Circuit
V
SUPPLY
0.1µF
V
DD
INPUT
IN
SHDN
OUT
OUTPUT
MAX7403
MAX7404
MAX7407
Pin Configuration
TOP VIEW
COM
1
8
7
CLK
SHDN
OS
OUT
CLOCK
CLK
MAX7400
MAX7403
MAX7404
MAX7407
GND
IN
2
COM
OS
0.1µF
GND
3
V
DD
4
MAX7400
MAX7403
MAX7404
MAX7407
SO/DIP
6
5
________________________________________________________________
Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
8th-Order, Lowpass, Elliptic,
Switched-Capacitor Filters
MAX7400/MAX7403/MAX7404/MAX7407
ABSOLUTE MAXIMUM RATINGS
V
DD
to GND
MAX7400/MAX7403 ..............................................-0.3V to +6V
MAX7404/MAX7407 ..............................................-0.3V to +4V
IN, OUT, COM, OS, CLK ............................-0.3V to (V
DD
+ 0.3V)
SHDN........................................................................-0.3V
to +6V
OUT Short-Circuit Duration...................................................1sec
Continuous Power Dissipation (T
A
= +70°C)
SO (derate 5.88mW/°C above +70°C) ..........................471mW
DIP (derate 9.1mW/°C above +70°C) ...........................727mW
Operating Temperature Ranges
MAX740_C_A .....................................................0°C to +70°C
MAX740_E_A ..................................................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10sec) .............................+300°C
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—MAX7400/MAX7403
(V
DD
= +5V, filter output measured at OUT, 10kΩ || 50pF load to GND at OUT,
SHDN
= V
DD
, OS = COM, 0.1µF from COM to GND,
f
CLK
= 100kHz, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at +25°C.)
PARAMETER
FILTER CHARACTERISTICS
Corner Frequency
Clock-to-Corner Ratio
Clock-to-Corner Tempco
Output Voltage Range
Output Offset Voltage
DC Insertion Gain with
Output Offset Removed
Total Harmonic Distortion
plus Noise
OS Voltage Gain to OUT
Input Voltage Range at OS
THD+N
A
OS
V
OS
Input, COM externally driven
COM Voltage Range
V
COM
Output, COM internally biased
Input Resistance at COM
Clock Feedthrough
Resistive Output Load Drive
Maximum Capacitive Load
at OUT
Input Leakage Current at COM
Input Leakage Current at OS
CLOCK
Internal Oscillator Frequency
Clock Input Current
Clock Input High
Clock Input Low
f
OSC
I
CLK
V
IH
V
IL
C
OSC
= 1000pF (Note 4)
V
CLK
= 0 or 5V
V
DD
- 0.5
0.5
29
38
±15
48
±30
kHz
µA
V
V
R
L
C
L
SHDN
= GND, V
COM
= 0 to V
DD
V
OS
= 0 to (V
DD
- 1V) (Note 3)
10
50
R
COM
V
DD
/ 2
- 0.5
V
DD
/ 2
- 0.2
75
V
OFFSET
V
IN
= V
COM
= V
DD
/ 2
V
COM
= V
DD
/ 2 (Note 2)
f
IN
= 200Hz, V
IN
= 4Vp-p,
measurement bandwidth = 22kHz
MAX7400
MAX7403
-0.1
0.25
±5
0.15
-82
-80
1
V
COM
±0.1
V
DD
/ 2
V
DD
/ 2
+ 0.5
f
C
f
CLK
/f
C
(Note 1)
0.001 to 10
100:1
10
V
DD
- 0.25
±25
0.3
ppm/°C
V
mV
dB
dB
V/V
V
kHz
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
V
DD
/ 2
V
DD
/ 2
+ 0.2
125
10
1
500
±0.1
±0.1
±10
±10
V
kΩ
mVp-p
kΩ
pF
µA
µA
2
_______________________________________________________________________________________
8th-Order, Lowpass, Elliptic,
Switched-Capacitor Filters
ELECTRICAL CHARACTERISTICS—MAX7400/MAX7403 (continued)
(V
DD
= +5V, filter output measured at OUT, 10kΩ || 50pF load to GND at OUT,
SHDN
= V
DD
, OS = COM, 0.1µF from COM to GND,
f
CLK
= 100kHz, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
POWER REQUIREMENTS
Supply Voltage
Supply Current
Shutdown Current
Power-Supply Rejection Ratio
SHUTDOWN
SHDN
Input High
SHDN
Input Low
SHDN
Input Leakage Current
V
SDH
V
SDL
V
SHDN
= 0 to V
DD
±0.1
V
DD
- 0.5
0.5
±10
V
V
µA
V
DD
I
DD
I
SHDN
PSRR
Operating mode, no load, IN = OS = COM
SHDN
= GND, CLK driven from 0 to V
DD
Measured at DC
4.5
2
0.2
60
5.5
3.5
1
V
mA
µA
dB
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX7400/MAX7403/MAX7404/MAX7407
ELECTRICAL CHARACTERISTICS—MAX7404/MAX7407
(V
DD
= +3V, filter output measured at OUT, 10kΩ || 50pF load to GND at OUT,
SHDN
= V
DD
, OS = COM, 0.1µF from COM to GND,
f
CLK
= 100kHz, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
FILTER CHARACTERISTICS
Corner Frequency
Clock-to-Corner Ratio
Clock-to-Corner Tempco
Output Voltage Range
Output Offset Voltage
DC Insertion Gain with Output
Offset Removed
Total Harmonic Distortion
plus Noise
OS Voltage Gain to OUT
Input Voltage Range at OS
COM Voltage Range
Input Resistance at COM
Clock Feedthrough
Resistive Output Load Drive
Maximum Capacitive Load
at OUT
Input Leakage Current at COM
Input Leakage Current at OS
R
L
C
L
SHDN
= GND, V
COM
= 0 to V
DD
V
OS
= 0 to (V
DD
- 1V) (Note 3)
10
50
THD+N
A
OS
V
OS
V
COM
R
COM
COM internally biased or externally driven
V
DD
/ 2
- 0.1
75
V
OFFSET
V
IN
= V
COM
= V
DD
/ 2
V
COM
= V
DD
/ 2 (Note 2)
f
IN
= 200Hz, V
IN
= 2.5Vp-p,
measurement bandwidth = 22kHz
MAX7404
MAX7407
-0.1
0.25
±5
0.1
-79
-77
1
V
COM
±0.1
V
DD
/ 2
125
10
1
500
±0.1
±0.1
±10
±10
V
DD
/ 2
+ 0.1
f
C
f
CLK
/f
C
(Note 1)
0.001 to 10
100:1
10
V
DD
- 0.25
±25
0.3
ppm/°C
V
mV
dB
dB
V/V
V
V
kΩ
mVp-p
kΩ
pF
µA
µA
kHz
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
_______________________________________________________________________________________
3
8th-Order, Lowpass, Elliptic,
Switched-Capacitor Filters
MAX7400/MAX7403/MAX7404/MAX7407
ELECTRICAL CHARACTERISTICS—MAX7404/MAX7407 (continued)
(V
DD
= +3V, filter output measured at OUT, 10kΩ || 50pF load to GND at OUT,
SHDN
= V
DD
, OS = COM, 0.1µF from COM to GND,
f
CLK
= 100kHz, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
CLOCK
Internal Oscillator Frequency
Clock Input Current
Clock Input High
Clock Input Low
POWER REQUIREMENTS
Supply Voltage
Supply Current
Shutdown Current
Power-Supply Rejection Ratio
SHUTDOWN
SHDN
Input High
SHDN
Input Low
SHDN
Input Leakage Current
V
SDH
V
SDL
V
S HDN
= 0 to V
DD
±0.1
V
DD
- 0.5
0.5
±10
V
V
µA
V
DD
I
DD
I
SHDN
PSRR
Operating mode, no load, IN = OS = COM
SHDN
= GND, CLK driven from 0 to V
DD
Measured at DC
2.7
2
0.2
60
3.6
3.5
1
V
mA
µA
dB
f
OSC
I
CLK
V
IH
V
IL
C
OSC
= 1000pF (Note 4)
V
CLK
= 0 or 3V
V
DD
- 0.5
0.5
26
34
±15
43
±30
kHz
µA
V
V
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
ELLIPTIC (r = 1.5) FILTER CHARACTERISTICS—MAX7400/MAX7404
(V
DD
= +5V for MAX7400, V
DD
= +3V for MAX7404; filter output measured at OUT; 10kΩ
||
50pF load to GND at OUT;
SHDN
= V
DD
;
V
COM
= V
OS
= V
DD
/ 2; f
CLK
= 100kHz; T
A
= T
MIN
to T
MAX
; unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
f
IN
= 0.371f
C
f
IN
= 0.587f
C
f
IN
= 0.737f
C
f
IN
= 0.868f
C
Insertion Gain Relative to DC Gain
(Note 5)
f
IN
= 0.940f
C
f
IN
= 0.988f
C
f
IN
= 1.000f
C
f
IN
= 1.500f
C
f
IN
= 1.601f
C
f
IN
= 2.020f
C
f
IN
= 4.020f
C
CONDITIONS
MIN
-0.20
-0.20
-0.20
-0.20
-0.20
-0.20
-0.20
TYP
-0.10
0.02
-0.08
0.06
-0.03
0.09
0.02
-82
-84
-83
-85
MAX
0.20
0.20
0.20
0.20
0.20
0.25
0.25
-75
-78
-78
-78
dB
UNITS
4
_______________________________________________________________________________________
8th-Order, Lowpass, Elliptic,
Switched-Capacitor Filters
ELLIPTIC (r = 1.2) FILTER CHARACTERISTICS—MAX7403/MAX7407
(V
DD
= +5V for MAX7403, V
DD
= +3V for MAX7407; filter output measured at OUT; 10kΩ
||
50pF load to GND at OUT;
SHDN
= V
DD
;
V
COM
= V
OS
= V
DD
/ 2; f
CLK
= 100kHz; T
A
= T
MIN
to T
MAX
; unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
f
IN
= 0.408f
C
f
IN
= 0.640f
C
f
IN
= 0.784f
C
f
IN
= 0.902f
C
Insertion Gain Relative to DC Gain
(Note 5)
f
IN
= 0.956f
C
f
IN
= 0.992f
C
f
IN
= 1.000f
C
f
IN
= 1.200f
C
f
IN
= 1.261f
C
f
IN
= 1.533f
C
f
IN
= 2.875f
C
CONDITIONS
MIN
-0.20
-0.20
-0.20
-0.20
-0.20
-0.20
-0.20
TYP
-0.11
0.02
-0.06
0.10
0.02
0.14
0.09
-58
-59
-60
-60
MAX
0.20
0.20
0.20
0.20
0.20
0.30
0.30
-50
-54
-54
-54
dB
UNITS
MAX7400/MAX7403/MAX7404/MAX7407
Note 1:
The maximum f
C
is defined as the clock frequency, f
CLK
= 100
·
f
C
, at which the peak SINAD drops to 68dB with a
sinusoidal input at 0.2f
C
.
Note 2:
DC insertion gain is defined as
∆V
OUT
/
∆V
IN
.
Note 3:
OS voltages above V
DD
- 1V saturate the input and result in a 75µA typical input leakage current.
Note 4:
For MAX7400/MAX7403, f
OSC
(kHz)
≅
38
·
10
3
/ C
OSC
(pF). For MAX7404/MAX7407, f
OSC
(kHz)
≅
34
·
10
3
/ C
OSC
(pF).
Note 5:
The input frequencies, f
IN
, are selected at the peaks and troughs of the frequency responses.
Typical Operating Characteristics
(V
DD
= +5V for MAX7400/MAX7403, V
DD
= +3V for MAX7404/MAX7407; V
COM
= V
OS
= V
DD
/ 2;
SHDN
= V
DD
; f
CLK
= 100kHz;
T
A
= +25°C; unless otherwise noted.)
MAX7400/MAX7404 (r = 1.5)
FREQUENCY RESPONSE
MAX7400/03-01
MAX7400/MAX7404 (r = 1.5)
PASSBAND FREQUENCY RESPONSE
MAX7400/03-02
MAX7400/MAX7404 (r = 1.5)
PHASE RESPONSE
-80
PHASE SHIFT (DEGREES)
-160
-240
-320
-400
-480
-560
-640
f
C
= 1kHz
MAX7400/03-03
20
f
C
= 1kHz
0
-20
GAIN (dB)
-40
-60
-80
-100
-120
0
1
2
3
4
5
INPUT FREQUENCY (kHz)
0.24
f
C
= 1kHz
0.20
0.16
GAIN (dB)
0.12
0.08
0.04
0
-0.04
-0.08
0
202
404
606
808
0
1010
0
300
600
900
1200
1500
INPUT FREQUENCY (Hz)
INPUT FREQUENCY (Hz)
_______________________________________________________________________________________
5
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
