IC-Mart Your Trusted Source for Active Filter IC Chips

(from leading manufacturers)

International Manufacturers of active filter ICs and classical models

• Analog Devices (ADI): LTC1563-2, LTC1563-3, LTC1564, ADA4432-1, LTC1064, LTC1067, LTC1060
• Maxim Integrated (ADI): MAX7400, MAX7403, MAX7411, MAX7401, MAX7410, MAX9502, MAX263, MAX268, MAX7490
• Texas Instruments (TI): UAF42, TPSF12C1, TPSF12C3, MF10  

Model	Manufacturer	Key Characteristics & Features
LTC1563-2	Analog Devices (ADI)	High-order low-pass filter with Butterworth response; provides the flattest response with no ripples in the passband.
LTC1563-3	Analog Devices (ADI)	Bessel response filter; features linear phase and constant group delay to prevent square wave distortion.
MAX7400	Maxim (ADI)	8th-order Elliptic switched-capacitor filter; provides extreme steepness and the narrowest transition band.
MAX7403	Maxim (ADI)	Switched-capacitor filter where cutoff frequency is proportional to an external clock frequency.
MAX7411	Maxim (ADI)	Butterworth response filter; maintains constant gain in the passband without ripples.
MAX7401	Maxim (ADI)	Bessel response filter; ensures signal shape integrity for pulse-type signals.
MAX7410	Maxim (ADI)	Chebyshev response filter; offers a fast, steep cut-off but introduces “ripple” (noise) in the passband.
UAF42	Texas Instruments (TI)	Universal active filter; can simultaneously output low-pass, high-pass, band-pass, and band-stop signals.
LTC1564	Analog Devices (ADI)	Digitally programmable 8th-order filter; features a 4-bit parallel interface to adjust gain and cutoff frequency on the fly.
ADA4432-1	Analog Devices (ADI)	Video reconstruction filter; designed for high bandwidth and DC restoration to ensure clear, ripple-free images.
MAX9502	Maxim (ADI)	Video reconstruction filter; removes high-frequency artifacts after DAC conversion.
TPSF12C1	Texas Instruments (TI)	Active EMI filter (Single-phase); senses common-mode noise and injects “anti-noise” current to reduce inductor size.
TPSF12C3	Texas Instruments (TI)	Active EMI filter (Three-phase); used for offensive filtering in power supplies to reduce EMC component footprint.
LTC1064	Analog Devices (ADI)	Typical Low Pass Filter (LPF) used for signal conditioning and anti-aliasing.
LTC1067	Analog Devices (ADI)	Configurable High Pass Filter (HPF); effectively removes 50/60Hz power line noise or low-frequency drift.
MAX263	Maxim (ADI)	Configurable High Pass Filter (HPF) used in audio processing and instrumentation.
MF10	Texas Instruments (TI)	Band Pass Filter (BPF); capable of extracting weak, narrow-band signals with a high Q-factor.
MAX268	Maxim (ADI)	Band Pass Filter (BPF) commonly used in sensor signal conditioning and communication receivers.
MAX7490	Maxim (ADI)	Band Rejection / Notch filter; ideal for eliminating specific interference like electrical grid humming.

China’s Manufacturers of active filter ICs and classical models

• SGMICRO: SGM9133, SGM9117
• 3PEAK: TPF110/110U/110L, TPF111, TPF131, TPF144

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Key Applications of Active Filter IC

1. Telecommunications: In smartphones and Wi-Fi modules, IC filters isolate the specific frequency bands used for LTE, 5G, or Bluetooth.
2. Data Conversion: Before an analog signal is turned into digital data (via an ADC), a “low-pass anti-aliasing filter” is used to ensure the signal is clean enough for the computer to read.
3. Audio Equipment: Used for equalization, noise reduction, and signal processing in everything from headphones to professional mixers.
4. Medical Devices: Filtering out muscle noise or electrical interference when measuring sensitive signals like an EKG or EEG.

Why use “Active” for naming these chips?

Active Filter IC has the ability to provide gain and impedance matching, in an “active” way. These ICs effectively isolate different stages of a circuit, by extracting or suppressing specific frequency bands while maintaining high input impedance and low output impedance. This has been done by using closed-loop feedback principles.

Why Active Filter IC important?

In analog circuit design, noise poses great troubles. How to get precise signal is the ultimate goal. Active Filter IC acts as a critical “gatekeeper” and “sculptor” of signals. When you are designing a high-fidelity audio system, a medical imaging device, or a next-generation industrial sensor, it is always know the importance of these ICs.

Two Core Technical Architectures Philosophies for Active Filter IC

There are generally two categorized Architectures Methods for Active Filter IC: Continuous-Time Filters and Switched-Capacitor Filters.

1. Continuous-Time Filters (RC-Based)

These filter chips use traditional resistor-capacitor structures internally.
The Advantage: Since they do not involve a sampling process, they are free from “aliasing” noise.
Typical Model: The LTC1563 series from ADI, for instance, is a high-order low-pass filter that allows engineers to set the cutoff frequency with just a single external resistor.
Best For: Ultra-low-noise applications like medical imaging or high-precision instrumentation.

2. Switched-Capacitor Filters (Clock-Based)

These filter ICs use high-speed switching to simulate resistors using capacitors, a “miracle of modern ICs design”.
The Advantage: The cutoff frequency Fc is proportional to an external clock frequency (often at a 100:1 ratio). It is easy to adjust a filter’s bandwidth from 1Hz to 10kHz simply by changing a PWM signal from a micro-controller.
Typical Model: Maxim’s (ADI) MAX7400 or MAX7403.
Best For: Systems where bandwidth needs to fluctuate or follow a specific frequency, such as in complex communication systems.

Model Types in terms of the Mathematics of Response

When choose a filter, frequency is important. And more importantly, it’s about the “attitude” the filter takes toward the signal. It should always keep in mind to balance frequency response against time-domain performance. 

Model Type	Technical Characteristics	Key Models
Butterworth	Flattest Response: No ripples in the passband; gain remains constant.	LTC1563-2, MAX7411
Bessel	Linear Phase: Constant group delay; ensures square waves don’t distort.	LTC1563-3, MAX7401
Elliptic	Extreme Steepness: The narrowest transition band with rapid stopband attenuation.	MAX7400 (8th order)
Chebyshev	Fast Cut-off: Very steep transition but introduces “ripple” (noise) in the passband.	MAX7410

Active Filter IC Functional Classifications:

Active Filter ICs can be also categorized by their specific utility in a signal chain.

1. Universal Active Filter ICs
   These are the “all-rounders.” A single chip can often output low-pass, high-pass, band-pass, and band-stop (notch) signals simultaneously.
   Industry Icon: The TI UAF42. By calculating a few external resistors, you can configure it for any classic response.
2. Anti-Aliasing & Digitally Programmable Filter ICs
   These filter ICs are used primarily before an Analog-to-Digital Converter (ADC) to prevent signal distortion.
   Key Model: LTC1564. This 8th-order filter features a 4-bit parallel interface, allowing a digital processor to adjust gain and cutoff frequency on the fly.
3. Video Reconstruction Filters
   They are designed for the high bandwidth and DC restoration needs of video signals.
   Key Models: ADA4432-1 (ADI) or MAX9502 (Maxim). They remove high-frequency artifacts after a DAC conversion to ensure clear, ripple-free images.
4. Active EMI Filters
   A revolutionary shift from “defensive” to “offensive” filtering in power supplies.
   Key Models: TI’s TPSF12C1 (Single-phase) or TPSF12C3 (Three-phase).
   The Tech: They sense common-mode noise on power lines and inject an equal but opposite “anti-noise” current, reducing the size of traditional EMC inductors by 50%–80%.

Common Types by Function

IC filters are classified by which part of the frequency spectrum they “let through”:

1. Low Pass Filters (LPF)
   Description: Allows signals below a specific cutoff frequency to pass while attenuating higher frequencies. This is the most common type used in signal conditioning.
   Typical Models: MAX7400 / LTC1064
   Key Manufacturers: Analog Devices (ADI) / Maxim Integrated
   Key Features:
   Anti-aliasing: Essential for pre-conditioning signals before Analog-to-Digital conversion (ADC).
   Steep Roll-off: Integrated LPFs (e.g., 8th-order) provide much sharper transitions than simple passive RC circuits.

2. High Pass Filters (HPF)
   Description: Allows signals above the cutoff frequency to pass, blocking DC offsets or low-frequency interference.
   Typical Models: LTC1067 / MAX263 (Configurable)
   Key Manufacturers: Analog Devices (ADI)
   Key Features:
   Baseline Smoothing: Effectively removes 50/60Hz power line noise or low-frequency drift.
   Precision: Widely used in audio processing and instrumentation to isolate high-frequency pulses.

3. Band Pass Filters (BPF)
   Description: Passes a specific range of frequencies around a center point while rejecting frequencies outside that range.
   Typical Models: MF10 / MAX268
   Key Manufacturers: Texas Instruments (TI) / Maxim Integrated
   Key Features:
   High Q-Factor: Capable of extracting weak, narrow-band signals from complex backgrounds.
   Industrial Use: Common in sensor signal conditioning and communication receivers.

4. Band Rejection / Notch Filters
   Description: Rejects a specific narrow frequency band (or a single frequency) while allowing all other frequencies to pass.
   Typical Models: MAX7490
   Key Manufacturers: Maxim Integrated (ADI)
   Key Features:
   Precise Suppression: Ideal for eliminating specific interference, such as humming from electrical grids.
   Signal Integrity: Maintains the rest of the signal spectrum while cutting out only the problematic frequency.