Rainbow Electronics MAX7407 User Manual

General Description

The MAX7400/MAX7403/MAX7404/MAX7407 8th-order,
lowpass, elliptic, switched-capacitor filters (SCFs) oper­ate 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 anti­aliasing and post-DAC filtering applications. They fea­ture 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 stop­band 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.

Applications

ADC Anti-Aliasing Speech Processing
Post-DAC Filtering Air-Bag Electronics
CT2 Base Stations

Features

♦ 8th-Order Lowpass Elliptic Filter
♦ Low Noise and Distortion

-82dB THD + Noise (MAX7400)

♦ Clock-Tunable Corner Frequency (1Hz to 10kHz)
♦ 100:1 Clock-to-Corner Ratio
♦ Single-Supply Operation

+5V (MAX7400/MAX7403)
+3V (MAX7404/MAX7407)

♦ Low Power

2mA (Operating Mode)

0.2µA (Shutdown Mode)

♦ Available in 8-Pin SO and DIP Packages
♦ Low Output Offset: ±5mV

MAX7400/MAX7403/MAX7404/MAX7407

8th-Order, Lowpass, Elliptic,

Switched-Capacitor Filters

________________________________________________________________

Maxim Integrated Products

1

V

DD

IN

CLK

OUT

GND

INPUT

0.1µF

0.1µF

CLOCK

SHDN

OUTPUT

V

SUPPLY

COM

OS

MAX7400
MAX7403
MAX7404
MAX7407

Typical Operating Circuit

19-4764; Rev 2; 6/99

Ordering Information continued at end of data sheet.

Pin Configuration

Ordering Information

Selector Guide

MAX7407 Elliptic (r = 1.2) +3

PART FILTER RESPONSE

OPERATING

VOLTAGE (V)

MAX7403

MAX7400 Elliptic (r = 1.5) +5

Elliptic (r = 1.2) +5

MAX7404 Elliptic (r = 1.5) +3

PART

MAX7400CSA

MAX7400CPA
MAX7400ESA -40°C to +85°C

0°C to +70°C

0°C to +70°C

TEMP. RANGE PIN-PACKAGE

8 SO
8 Plastic DIP
8 SO

MAX7400EPA -40°C to +85°C 8 Plastic DIP

For free samples & the latest literature: http://www.maxim-ic.com, or phone [phone].
For small orders, phone [phone].

TOP VIEW

COM

1

GND

2

MAX7400
MAX7403

3

MAX7404
MAX7407

4

DD

SO/DIP

87CLK

SHDNIN

OS

6

OUTV

5

MAX7400/MAX7403/MAX7404/MAX7407

8th-Order, Lowpass, Elliptic,
Switched-Capacitor Filters

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS—MAX7400/MAX7403

(VDD= +5V, filter output measured at OUT, 10kΩ || 50pF load to GND at OUT, SHDN = VDD, OS = COM, 0.1µF from COM to GND,

f

CLK

= 100kHz, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at +25°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.

VDDto 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

VOS= 0 to (VDD- 1V) (Note 3)

(Note 1)

SHDN = GND, V

COM

= 0 to V

DD

VIN= V

COM

= VDD/ 2

Output, COM internally biased

V

COM

= VDD/ 2 (Note 2)

Input, COM externally driven

CONDITIONS

µA±0.1 ±10Input Leakage Current at OS

µA±0.1 ±10Input Leakage Current at COM

pF50 500C

L

Maximum Capacitive Load
at OUT

kΩ10 1R

L

Resistive Output Load Drive

mVp-p10Clock Feedthrough

kΩ75 125R

COM

Input Resistance at COM

VDD/ 2

V

DD

/ 2

V

DD

/ 2

- 0.2 + 0.2

V

COM

COM Voltage Range V

VDD/ 2

V

DD

/ 2

V

DD

/ 2

- 0.5 + 0.5

100:1f

CLK/fC

Clock-to-Corner Ratio

kHz0.001 to 10f

C

Corner Frequency

VV

COM

±0.1V

OS

Input Voltage Range at OS

-82

ppm/°C10Clock-to-Corner Tempco

V0.25 VDD- 0.25Output Voltage Range

mV±5 ±25V

OFFSET

Output Offset Voltage

dB-0.1 0.15 0.3

DC Insertion Gain with
Output Offset Removed

UNITSMIN TYP MAXSYMBOLPARAMETER

C

OSC

= 1000pF (Note 4) kHz29 38 48f

OSC

Internal Oscillator Frequency

V

CLK

= 0 or 5V µA±15 ±30I

CLK

Clock Input Current

VDD- 0.5V

IH

V

0.5V

IL

Clock Input High

fIN= 200Hz, VIN= 4Vp-p,
measurement bandwidth = 22kHz

dB

-80

THD+N

Total Harmonic Distortion
plus Noise

MAX7400
MAX7403

V/V1A

OS

OS Voltage Gain to OUT

Clock Input Low V

FILTER CHARACTERISTICS

CLOCK

MAX7400/MAX7403/MAX7404/MAX7407

8th-Order, Lowpass, Elliptic,

Switched-Capacitor Filters

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS—MAX7400/MAX7403 (continued)

(VDD= +5V, filter output measured at OUT, 10kΩ || 50pF load to GND at OUT, SHDN = VDD, OS = COM, 0.1µF from COM to GND,
f

CLK

= 100kHz, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.)

ELECTRICAL CHARACTERISTICS—MAX7404/MAX7407

(VDD= +3V, filter output measured at OUT, 10kΩ || 50pF load to GND at OUT, SHDN = VDD, OS = COM, 0.1µF from COM to GND,
f

CLK

= 100kHz, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.)

SHUTDOWN

POWER REQUIREMENTS

SHDN Input Leakage Current

±0.1 ±10 µAV

SHDN

= 0 to V

DD

SHDN Input High

V

SDL

0.5

VV

SDH

VDD- 0.5

PARAMETER SYMBOL MIN TYP MAX UNITS

Power-Supply Rejection Ratio PSRR 60 dB

Shutdown Current I

SHDN

0.2 1 µA

Supply Voltage V

DD

4.5 5.5 V

Supply Current I

DD

2 3.5 mA

CONDITIONS

Measured at DC

SHDN = GND, CLK driven from 0 to V

DD

Operating mode, no load, IN = OS = COM

FILTER CHARACTERISTICS

Total Harmonic Distortion
plus Noise

PARAMETER SYMBOL MIN TYP MAX UNITS

DC Insertion Gain with Output
Offset Removed

-0.1 0.1 0.3 dB

Output Offset Voltage V

OFFSET

±5 ±25 mV

Output Voltage Range 0.25 VDD- 0.25 V

Clock-to-Corner Tempco 10 ppm/°C

THD+N

-77

dB

MAX7407

MAX7404 -79

OS Voltage Gain to OUT A

OS

1 V/V

Input Voltage Range at OS V

OS

V

COM

±0.1 V

Corner Frequency f

C

0.001 to 10 kHz

Clock-to-Corner Ratio f

CLK/fC

100:1

VDD/ 2

V

DD

/ 2

V

DD

/ 2

- 0.1 + 0.1

VCOM Voltage Range V

COM

Input Resistance at COM R

COM

75 125 kΩ
Clock Feedthrough 10 mVp-p
Resistive Output Load Drive R

L

10 1 kΩ
Maximum Capacitive Load

at OUT

C

L

50 500 pF
Input Leakage Current at COM ±0.1 ±10 µA

Input Leakage Current at OS ±0.1 ±10 µA

CONDITIONS

COM internally biased or externally driven

V

COM

= VDD/ 2 (Note 2)

VIN= V

COM

= VDD/ 2

fIN= 200Hz, VIN= 2.5Vp-p,
measurement bandwidth = 22kHz

SHDN = GND, V

COM

= 0 to V

DD

(Note 1)

VOS= 0 to (VDD- 1V) (Note 3)

SHDN Input Low

V

MAX7400/MAX7403/MAX7404/MAX7407

8th-Order, Lowpass, Elliptic,
Switched-Capacitor Filters

4 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS—MAX7404/MAX7407 (continued)

(VDD= +3V, filter output measured at OUT, 10kΩ || 50pF load to GND at OUT, SHDN = VDD, OS = COM, 0.1µF from COM to GND,
f

CLK

= 100kHz, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.)

ELLIPTIC (r = 1.5) FILTER CHARACTERISTICS—MAX7400/MAX7404

(VDD= +5V for MAX7400, VDD= +3V for MAX7404; filter output measured at OUT; 10kΩ || 50pF load to GND at OUT; SHDN = VDD;
V

COM

= VOS= V

DD

/ 2; f

CLK

= 100kHz; TA= T

MIN

to T

MAX

; unless otherwise noted. Typical values are at TA= +25°C.)

V

CLK

= 0 or 3V

C

OSC

= 1000pF (Note 4)

V

CONDITIONS

VDD- 0.5V

IH

µA±15 ±30I

CLK

Clock Input Current

kHz26 34 43f

OSC

Internal Oscillator Frequency

0.5V

IL

Clock Input High

UNITSMIN TYP MAXSYMBOLPARAMETER

SHDN = GND, CLK driven from 0 to V

DD

Operating mode, no load, IN = OS = COM

Measured at DC

µA0.2 1I

SHDN

mA2 3.5I

DD

Supply Current

V2.7 3.6V

DD

Supply Voltage

60PSRR

Shutdown Current
Power-Supply Rejection Ratio dB

VDD- 0.5V

SDH

SHDN Input High

V

V

SHDN

= 0 to V

DD

±0.1 ±10

SHDN Input Leakage Current

µA

V

SDL

0.5

Clock Input Low

SHDN Input Low

V

V

CLOCK

POWER REQUIREMENTS

SHUTDOWN

dB

CONDITIONS UNITSMIN TYP MAXPARAMETER

fIN= 0.371f

C

-0.20 -0.10 0.20

fIN= 0.737f

C

fIN= 0.587f

C

-0.20 -0.08 0.20

-0.20 0.02 0.20

fIN= 0.940f

C

fIN= 0.868f

C

-0.20 -0.03 0.20

fIN= 1.000f

C

fIN= 0.988f

C

-0.20 0.02 0.25

-0.20 0.09 0.25

-0.20 0.06 0.20

fIN= 1.601f

C

fIN= 1.500f

C

-84 -78

fIN= 4.020f

C

fIN= 2.020f

C

-85 -78

Insertion Gain Relative to DC Gain
(Note 5)

-83 -78

-82 -75