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Typical operating characteristics – Rainbow Electronics MAX7407 User Manual

Page 5

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8th-Order, Lowpass, Elliptic,

Switched-Capacitor Filters

_______________________________________________________________________________________

5

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.

ELLIPTIC (r = 1.2) FILTER CHARACTERISTICS—MAX7403/MAX7407

(V

DD

= +5V for MAX7403, V

DD

= +3V for MAX7407; filter output measured at OUT; 10k

||

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.)

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.)

-120

-80

-100

-40

-60

0

-20

20

0

1

2

3

4

5

MAX7400/MAX7404 (r = 1.5)

FREQUENCY RESPONSE

MAX7400/03-01

INPUT FREQUENCY (kHz)

GAIN (dB)

f

C

= 1kHz

-0.08

0

-0.04

0.12

0.08

0.04

0.20

0.16

0.24

0

202

404

606

808

1010

MAX7400/MAX7404 (r = 1.5)

PASSBAND FREQUENCY RESPONSE

MAX7400/03-02

INPUT FREQUENCY (Hz)

GAIN (dB)

f

C

= 1kHz

-640

-480

-560

-240

-320

-400

-80

-160

0

0

300

600

900

1200

1500

MAX7400/MAX7404 (r = 1.5)

PHASE RESPONSE

MAX7400/03-03

INPUT FREQUENCY (Hz)

PHASE SHIFT (DEGREES)

f

C

= 1kHz

PARAMETER

MIN

TYP

MAX

UNITS

-58

-50

-60

-54

Insertion Gain Relative to DC Gain
(Note 5)

-60

-54

f

IN

= 1.533f

C

dB

f

IN

= 2.875f

C

-59

-54

f

IN

= 1.200f

C

f

IN

= 1.261f

C

-0.20

0.10

0.20

-0.20

0.14

0.30

CONDITIONS

-0.20

0.09

0.30

f

IN

= 0.992f

C

f

IN

= 1.000f

C

-0.20

0.02

0.20

f

IN

= 0.902f

C

f

IN

= 0.956f

C

-0.20

0.02

0.20

-0.20

-0.06

0.20

f

IN

= 0.640f

C

f

IN

= 0.784f

C

-0.20

-0.11

0.20

f

IN

= 0.408f

C

MAX7400/MAX7403/MAX7404/MAX7407