Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsLinear ICsMAX7407ESA+

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.

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

CLK

OUT

GND

INPUT

0.1µF

CLOCK

SHDN

OUTPUT

SUPPLY

COM

MAX7400

MAX7403

MAX7404

MAX7407

OUTV

CLK

SHDNIN

GND

COM

SO/DIP

TOP VIEW

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

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 1-800-998-8800.

For small orders, phone 1-800-835-8769.

Summary of content (12 pages)

PAGE 1
9-4764; Rev 2; 6/99 8th-Order, Lowpass, Elliptic, Switched-Capacitor Filters 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.
PAGE 2
MAX7400/MAX7403/MAX7404/MAX7407 8th-Order, Lowpass, Elliptic, Switched-Capacitor Filters ABSOLUTE MAXIMUM RATINGS VDD to GND MAX7400/MAX7403 ..............................................-0.3V to +6V MAX7404/MAX7407 ..............................................-0.3V to +4V IN, OUT, COM, OS, CLK ............................-0.3V to (VDD + 0.3V) SHDN........................................................................-0.3V to +6V OUT Short-Circuit Duration.................................................
PAGE 3
8th-Order, Lowpass, Elliptic, Switched-Capacitor Filters (VDD = +5V, filter output measured at OUT, 10kΩ || 50pF load to GND at OUT, SHDN = VDD, OS = COM, 0.1µF from COM to GND, fCLK = 100kHz, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 5.5 V 2 3.5 mA 1 POWER REQUIREMENTS Supply Voltage VDD Supply Current IDD 4.
PAGE 4
MAX7400/MAX7403/MAX7404/MAX7407 8th-Order, Lowpass, Elliptic, Switched-Capacitor Filters 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, fCLK = 100kHz, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.
PAGE 5
8th-Order, Lowpass, Elliptic, Switched-Capacitor Filters (VDD = +5V for MAX7403, VDD = +3V for MAX7407; filter output measured at OUT; 10kΩ || 50pF load to GND at OUT; SHDN = VDD; VCOM = VOS = VDD / 2; fCLK = 100kHz; TA = TMIN to TMAX; unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER CONDITIONS Insertion Gain Relative to DC Gain (Note 5) MIN TYP MAX fIN = 0.408fC -0.20 -0.11 0.20 fIN = 0.640fC -0.20 0.02 0.20 fIN = 0.784fC -0.20 -0.06 0.20 fIN = 0.902fC -0.20 0.10 0.
PAGE 6
Typical Operating Characteristics (continued) (VDD = +5V for MAX7400/MAX7403, VDD = +3V for MAX7404/MAX7407; VCOM = VOS = VDD / 2; SHDN = VDD; fCLK = 100kHz; TA = +25°C; unless otherwise noted.) MAX7403/MAX7407 (r = 1.2) PASSBAND FREQUENCY RESPONSE 0.24 0.16 -20 0.08 GAIN (dB) 0 -40 -0.08 -80 -0.16 -100 -0.24 -120 fC = 1kHz -80 1 2 3 4 5 202 404 606 808 1010 0 240 480 720 960 SUPPLY CURRENT vs. SUPPLY VOLTAGE SUPPLY CURRENT vs. TEMPERATURE OFFSET VOLTAGE vs. SUPPLY VOLTAGE 1.
PAGE 7
8th-Order, Lowpass, Elliptic, Switched-Capacitor Filters THD PLUS NOISE vs. INPUT SIGNAL AMPLITUDE AND RESISTIVE LOAD (MAX7403) THD PLUS NOISE vs. INPUT SIGNAL AMPLITUDE (MAX7403) -40 -50 B D -70 -20 C -40 -70 -90 3 4 RL = 500Ω A 2800 14 1400 80 RL = 1kΩ B 2000 10 1000 80 RL = 10kΩ C 1000 5 500 80 D 200 1 100 22 -60 -90 2 fIN (Hz) -50 -80 1 0 5 1 2 3 4 5 AMPLITUDE (Vp-p) AMPLITUDE (Vp-p) THD PLUS NOISE vs.
PAGE 8
Typical Operating Characteristics (continued) (VDD = +5V for MAX7400/MAX7403, VDD = +3V for MAX7404/MAX7407; VCOM = VOS = VDD / 2; SHDN = VDD; fCLK = 100kHz; TA = +25°C; unless otherwise noted.) 10 1 0.1 0.01 1.15 1.10 MAX7404 MAX7407 1.05 1.00 0.95 MAX7400 MAX7403 0.90 0.85 10 100 COSC CAPACITANCE (nF) 1000 COSC = 390pF 1.03 MAX7400 MAX7403 1.02 1.01 1.00 0.99 MAX7404 MAX7407 0.98 0.97 0.96 0.80 1 0.1 1.04 NORMALIZED OSCILLATOR FREQUENCY 100 COSC = 390pF MAX7400 toc20 1000 1.
PAGE 9
8th-Order, Lowpass, Elliptic, Switched-Capacitor Filters The MAX7400/MAX7403/MAX7404/MAX7407 family of 8th-order, lowpass filters provides sharp rolloff with good stopband rejection. All parts operate with a 100:1 clock-to-corner frequency ratio and a 10kHz maximum corner frequency. These devices accept a single +5V (MAX7400/MAX7403) or +3V (MAX7404/ MAX7407) supply. Figure 1 shows the functional diagram. Most switched-capacitor filters (SFCs) are designed with biquadratic sections.
PAGE 10
VSUPPLY RIPPLE 0.1µF fC VDD f TRANSITION RATIO = S fC GAIN (dB) MAX7400/MAX7403/MAX7404/MAX7407 8th-Order, Lowpass, Elliptic, Switched-Capacitor Filters INPUT SHDN OUT IN OUTPUT COM 0.1µF fS CLOCK CLK MAX7400 MAX7403 MAX7404 MAX7407 50k OS 0.1µF GND PASSBAND fS FREQUENCY Figure 3. Elliptic Filter Response Figure 4. Offset Adjustment Circuit Clock Signal External Clock The MAX7400/MAX7403/MAX7404/MAX7407 SCFs were designed for use with external clocks that have a 40% to 60% duty cycle.
PAGE 11
8th-Order, Lowpass, Elliptic, Switched-Capacitor Filters Power Supplies The MAX7400/MAX7403 operate from a single +5V supply. The MAX7404/MAX7407 operate from a single +3V supply. Bypass VDD to GND with a 0.1µF capacitor. If dual supplies are required, connect COM to the system ground and GND to the negative supply. Figure 5 shows an example of dual-supply operation. Singlesupply and dual-supply performance are equivalent.
PAGE 12
Ordering Information (continued) PART TEMP.