Rainbow Electronics MAX7491 - Manual

General Description
The MAX7490/MAX7491 consist of two identical low-
power, low-voltage, wide dynamic range, Rail-to-Rail
® ,
2nd-order switched-capacitor building blocks. Each of
the two filter sections, together with two to four external
resistors, can generate all standard 2nd-order func-
tions: bandpass, lowpass, highpass, and notch (band
reject). Three of these functions are simultaneously
available. Fourth-order filters can be obtained by cas-
cading the two 2nd-order filter sections. Similarly, high-
er order filters can easily be created by cascading
multiple MAX7490/MAX7491s.
Two clocking options are available: self-clocking
(through the use of an external capacitor) or external
clocking for tighter cutoff frequency control. The clock-
to-center frequency ratio is 100:1. Sampling is done at
twice the clock frequency, further separating the cutoff
frequency and Nyquist frequency.
The MAX7490/MAX7491 have an internal rail splitter
that establishes a precise common voltage needed for
single-supply operation. The MAX7490 operates from a
single +5V supply and the MAX7491 operates from a
single +3V supply. Both devices feature a low-power
shutdown mode and come in a 16-pin QSOP package.
________________________Applications
Tunable Active Filters
Multipole Filters
ADC Anti-Aliasing
Post-DAC Filtering
Adaptive Filtering
Phase-Locked Loops (PLLs)
Set-Top Boxes
Features
♦ Dual 2nd-Order Filter in a 16-Pin QSOP Package
♦ High Accuracy
Q Accuracy: ±0.2%
Clock-to-Center Frequency Error: ±0.2%
♦ Rail-to-Rail Input and Output Operation
♦ Single-Supply Operation: +5V (MAX7490)
or +3V (MAX7491)
♦ Internal or External Clock
♦ Highpass, Lowpass, Bandpass, and Notch Filters
♦ Clock-to-Center Frequency Ratio of 100:1
♦ Internal Sampling-to-Center Frequency Ratio
of 200:1
♦ Center Frequency up to 40kHz
♦ Easily Cascaded for Multipole Filters
♦ Low-Power Shutdown: <1µA Supply Current
MAX7490/MAX7491
Dual Universal Switched-Capacitor Filters
________________________________________________________________ Maxim Integrated Products 1
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
LPA LPB
BPB
NB/HPB
INVB
SB
COM
EXTCLK
CLK
TOP VIEW
MAX7490
MAX7491
QSOP
BPA
NA/HPA
SHDN
INVA
SA
GND
V DD
Pin Configuration
19-1768; Rev 0; 7/00
For free samples and the latest literature, visit www.maxim-ic.com or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
Ordering Information
Rail-to-Rail is a registered trademark of Nippon Motorola, Ltd.
PART TEMP. RANGE
PIN-
PACKAGE
SUPPLY
VOLTAGE
(+V)
MAX7490CEE 0 °C to +70°C 16 QSOP 5
MAX7490EEE -40 °C to +85°C 16 QSOP 5
MAX7491CEE 0 °C to +70°C 16 QSOP 3
MAX7491EEE -40 °C to +85°C 16 QSOP 3
Typical Application Circuit appears at end of data sheet.