19-1378; Rev 1; 10/98
5th-Order, Lowpass, Elliptic,
Switched-Capacitor Filters
General Description
The MAX7408/MAX7411/MAX7412/MAX7415 5th-order,
lowpass, elliptic, switched-capacitor filters (SCFs) oper-
ate from a single +5V (MAX7408/MAX7411) or +3V
(MAX7412/MAX7415) supply. The devices draw only
1.2mA of supply current and allow corner frequencies
from 1Hz to 15kHz, making them ideal for low-power
post-DAC filtering and anti-aliasing applications. They
can be put into a low-power mode, reducing 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. An offset-adjust pin
allows for adjustment of the DC output level.
The MAX7408/MAX7412 deliver 53dB of stopband
rejection and a sharp rolloff with a transition ratio of 1.6.
The MAX7411/MAX7415 achieve a sharper rolloff with a
transition ratio of 1.25 while still providing 37dB of stop-
band rejection. Their fixed response limits the design
task to selecting a clock frequency.
o
5th-Order, Elliptic Lowpass Filters
o
Low Noise and Distortion: -80dB THD + Noise
o
Clock-Tunable Corner Frequency (1Hz to 15kHz)
o
Single-Supply Operation
+5V (MAX7408/MAX7411)
+3V (MAX7412/MAX7415)
o
Low Power
1.2mA (operating mode)
0.2µA (shutdown mode)
o
Available in 8-Pin µMAX/DIP Packages
o
Low Output Offset: ±4mV
Features
MAX7408/MAX7411/MAX7412/MAX7415
Ordering Information
PART
MAX7408CPA
MAX7408CUA
MAX7408EPA
MAX7408EUA
MAX7411CPA
MAX7411CUA
MAX7411EPA
MAX7411EUA
MAX7412CPA
MAX7412CUA
MAX7412EPA
MAX7412EUA
MAX7415CPA
MAX7415CUA
MAX7415EPA
MAX7415EUA
TEMP. RANGE
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
8 Plastic DIP
8 µMAX
8 Plastic DIP
8 µMAX
8 Plastic DIP
8 µMAX
8 Plastic DIP
8 µMAX
8 Plastic DIP
8 µMAX
8 Plastic DIP
8 µMAX
8 Plastic DIP
8 µMAX
8 Plastic DIP
8 µMAX
Applications
ADC Anti-Aliasing
Post-DAC Filtering
CT2 Base Stations
Speech Processing
Selector Guide
PART
MAX7408
MAX7411
MAX7412
MAX7415
TRANSITION RATIO
r = 1.6
r = 1.25
r = 1.6
r = 1.25
OPERATING
VOLTAGE (V)
+5
+5
+3
+3
Typical Operating Circuit
V
SUPPLY
0.1µF
V
DD
INPUT
IN
SHDN
OUT
OUTPUT
Pin Configuration
TOP VIEW
COM
1
IN
2
COM
OS
0.1µF
GND
3
8
7
CLK
SHDN
OS
OUT
CLOCK
CLK
MAX7408
MAX7411
MAX7412
MAX7415
GND
V
DD
4
MAX7408
MAX7411
MAX7412
MAX7415
µMAX/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.
5th-Order, Lowpass, Elliptic,
Switched-Capacitor Filters
MAX7408/MAX7411/MAX7412/MAX7415
ABSOLUTE MAXIMUM RATINGS
V
DD
to GND ..............................................................-0.3V to +6V
IN, OUT, COM, OS, CLK,
SHDN
................-0.3V to (V
DD
+ 0.3V)
OUT Short-Circuit Duration...................................................1sec
Continuous Power Dissipation (T
A
= +70°C)
8-Pin DIP (derate 6.90mW/°C above +70°C) ...............552mW
8-Pin µMAX (derate 4.1mW/°C above +70°C) .............330mW
Operating Temperature Ranges
MAX74_ _C_A .....................................................0°C to +70°C
MAX74_ _E_A ..................................................-40°C to +85°C
Storage Temperature Range .............................-65°C to +160°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—MAX7408/MAX7411
(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
FILTER
Corner-Frequency Range
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
Offset Voltage Gain
THD+N
A
OS
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
OS to OUT
Input, COM externally driven
COM Voltage Range
V
COM
Output, COM internally driven
Input Voltage Range at OS
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 Output Current
(Internal Oscillator Mode)
Clock Input High
Clock Input Low
f
OSC
I
CLK
V
IH
V
IL
4.5
0.5
C
OSC
= 1000pF (Note 3)
19
27
±12
34
±20
kHz
µA
V
V
R
L
C
L
SHDN
= GND, V
COM
= 0 to V
DD
V
OS
= 0 to V
DD
V
OS
R
COM
T
A
= +25°C
10
50
Measured with respect to COM
110
V
DD
- 0.5
2
V
DD
- 0.2
2
0
0.25
±4
0.2
-81
1
V
DD
2
V
DD
2
±0.1
180
5
1
500
±0.2
±0.2
±10
±10
V
DD
+ 0.5
2
V
V
DD
+ 0.2
2
V
kΩ
mVp-p
kΩ
pF
µA
µA
f
C
f
CLK
/f
C
(Note 1)
0.001 to 15
100:1
10
V
DD
- 0.25
±25
0.4
ppm/°C
V
mV
dB
dB
V/V
kHz
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
2
_______________________________________________________________________________________
5th-Order, Lowpass, Elliptic,
Switched-Capacitor Filters
ELECTRICAL CHARACTERISTICS—MAX7408/MAX7411 (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
±0.2
4.5
0.5
±10
V
V
µA
V
DD
I
DD
I
SHDN
PSRR
Operating mode, no load
SHDN
= GND
Measured at DC
4.5
1.16
0.2
70
5.5
1.5
1
V
mA
µA
dB
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX7408/MAX7411/MAX7412/MAX7415
ELECTRICAL CHARACTERISTICS—MAX7412/MAX7415
(V
DD
= +3V, filter output measured at OUT pin, 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 Range
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
Offset Voltage Gain
COM Voltage Range
Input Voltage Range at OS
Input Resistance at COM
Clock Feedthrough
Resistance 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
THD+N
A
OS
V
COM
V
OS
R
COM
T
A
= +25°C
10
50
Measured with respect to COM
110
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
OS to OUT
V
DD
- 0.1
2
0
0.25
±4
0.2
-79
1
V
DD
2
±0.1
180
3
1
500
±0.2
±0.2
±10
±10
V
DD
+ 0.1
2
f
C
f
CLK/
f
C
(Note 1)
0.001 to 15
100:1
10
V
DD
- 0.25
±25
0.4
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
5th-Order, Lowpass, Elliptic,
Switched-Capacitor Filters
MAX7408/MAX7411/MAX7412/MAX7415
ELECTRICAL CHARACTERISTICS—MAX7412/MAX7415 (continued)
(V
DD
= +3V, filter output measured at OUT pin, 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 Output Current
(Internal Oscillator Mode)
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
SHDN
= 0 to V
DD
±0.2
2.5
0.5
±10
V
V
µA
V
DD
I
DD
I
SHDN
PSRR
Operating mode, no load
SHDN
= GND
Measured at DC
2.7
1.13
0.2
70
3.6
1.5
1
V
mA
µA
dB
f
OSC
I
CLK
V
IH
V
IL
C
OSC
= 1000pF (Note 3)
V
CLK
= 0 or 3V
2.5
0.5
19
27
±12
34
±20
kHz
µA
V
V
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
ELLIPTIC FILTER (r = 1.6) CHARACTERISTICS—MAX7408/MAX7412
(V
DD
= +5V for MAX7408, V
DD
= +3V for MAX7412; 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.) (Note 3)
PARAMETER
f
IN
= 0.34f
C
f
IN
= 0.63f
C
f
IN
= 0.84f
C
Insertion Gain
with DC Gain Error Removed
(Note 4)
f
IN
= 0.96f
C
f
IN
= f
C
f
IN
= 1.60f
C
f
IN
= 1.90f
C
f
IN
= 4.62f
C
CONDITIONS
MIN
-0.4
-0.4
-0.4
-0.4
-0.7
TYP
-0.2
0.2
-0.2
0.2
-0.2
-53.4
-53.4
-53.4
MAX
0.4
0.4
0.4
0.4
0.2
-50
-50
-50
dB
UNITS
4
_______________________________________________________________________________________
5th-Order, Lowpass, Elliptic,
Switched-Capacitor Filters
ELLIPTIC FILTER (r = 1.25) CHARACTERISTICS—MAX7411/MAX7415
(V
DD
= +5V for MAX7411, V
DD
= +3V for MAX7415; 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.) (Note 3)
PARAMETER
f
IN
= 0.38f
C
f
IN
= 0.68f
C
f
IN
= 0.87f
C
Insertion Gain
with DC Gain Error Removed
(Note 4)
f
IN
= 0.97f
C
f
IN
= f
C
f
IN
= 1.25f
C
f
IN
= 1.43f
C
f
IN
= 3.25f
C
CONDITIONS
MIN
-0.4
-0.4
-0.4
-0.4
-0.7
TYP
-0.2
0.2
-0.2
0.2
-0.2
-38.5
-37.2
-37.2
MAX
0.4
0.4
0.4
0.4
0.2
-34
-35
-35
dB
UNITS
MAX7408/MAX7411/MAX7412/MAX7415
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:
f
OSC
(kHz)
≈
27
·
10
3
/ C
OSC
(C
OSC
in pF).
Note 4:
The input frequencies, f
IN
, are selected at the peaks and troughs of the ideal elliptic frequency responses.
Typical Operating Characteristics
(V
DD
= +5V for MAX7408/MAX7411, V
DD
= +3V for MAX7412/MAX7415; f
CLK
= 100kHz;
SHDN
= V
DD
; V
COM
= V
OS
= V
DD
/ 2;
T
A
= +25°C; unless otherwise noted.)
MAX7408/MAX7412
FREQUENCY RESPONSE
MAX7408/11-01
MAX7411/MAX7415
FREQUENCY RESPONSE
f
C
= 1kHz
r = 1.25
MAX7408/11-02
MAX7408/MAX7412
PASSBAND FREQUENCY RESPONSE
MAX7408/11-03
20
0
-20
GAIN (dB)
f
C
= 1kHz
r = 1.6
20
0
-20
GAIN (dB)
0.2
0
-0.2
GAIN (dB)
-0.4
-0.6
-0.8
-1.0
-1.2
f
C
= 1kHz
r = 1.6
0
204
408
612
816
-40
-60
-80
-100
-120
0
1
2
3
4
5
INPUT FREQUENCY (kHz)
-40
-60
-80
-100
-120
0
1
2
3
4
5
INPUT FREQUENCY (kHz)
1.02k
INPUT FREQUENCY (Hz)
_______________________________________________________________________________________
5
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