Microprocessor Programmable Universal Active Filters

 

Part Number	Replacement	Explanation

Description

Create a design and simulate using EE-Sim^® tools:

The MAX260/MAX261/MAX262 CMOS dual second-order universal switched-capacitor active filters allow microprocessor control of precise filter functions. No external components are required for a variety of bandpass, lowpass, highpass, notch, and allpass configurations. Each device contains two second-order filter sections that place center frequency, Q, and filter operating mode under programmed control.

An input clock, along with a 6-bit f₀ program input, determine the filter's center or corner frequency without affecting other filter parameters. The filter Q is also programmed independently. Separate clock inputs for each filter section operate with either a crystal, RC network, or external clock generator.

The MAX260 has offset and DC specifications superior to the MAX261 and MAX262 and a center frequency (f₀) range of 7.5kHz. The MAX261 handles center frequencies to 57kHz, while the MAX262 extends the center frequency range to 140kHz by employing lower clock-to-f₀ ratios. All devices are available in 24-pin DIP and small outline packages in commercial, extended, and military temperature ranges.

MAX260, MAX261, MAX262: Functional Diagram Enlarge+

Key Features

• Filter Design Software Available
• Microprocessor Interface
• 64-Step Center Frequency Control
• 128-Step Q Control
• Independent Q and f₀ Programming
• Guaranteed Clock to f₀ Ratio-1% (A grade)
• 75kHz f₀ Range (MAX262)
• Single +5V and ±5V Operation

Applications/Uses

• µP-Tuned Filters
• Adaptive Filters
• Anti-Aliasing Filters
• Digital Signal Processing (DSP)
• Phase-Locked Loops (PLLs)
• Signal Analysis