Krohn-Hite 3323

The Krohn-Hite 3323 is a digitally tuned, dual-channel variable filter delivering precision signal conditioning across 0.01 Hz to 99.9 kHz. Each isolated channel operates independently with selectable low-pass, high-pass, band-pass, and band-reject configurations. Engineers configure cutoff frequencies via three decade switches and a six-position multiplier, achieving 24 dB/octave attenuation per channel or 48 dB/octave when cascaded. The instrument delivers maximum attenuation exceeding 80 dB to 100 kHz, with pass-band gains of 0 dB or 20 dB and output impedance of 50 ohms.

## Technical Specifications

• **Channels:** 2 (isolated, independent power supplies and connectors)
• **Cutoff Frequency Range:** 0.01 Hz to 99.9 kHz (low-pass, high-pass, band-reject)
• **Band-Reject Null Operation:** 0.01 Hz to 10 kHz
• **High-Pass Upper 3 dB Point:** Approximately 1 MHz
• **Attenuation Slope:** 24 dB/octave per channel; 48 dB/octave (cascaded same mode)
• **Maximum Attenuation:** >80 dB (to 100 kHz); 60 dB at 1 MHz
• **Pass-Band Gain:** 0 dB (unity) or 20 dB (gain of 10)
• **Maximum Output Voltage:** ±7 V peak (0 dB gain to 500 kHz); ±0.7 V peak (20 dB gain to 500 kHz); ±3 V peak (20 dB gain at 1 MHz, open circuit)
• **Maximum Output Current:** ±70 mA peak (to 500 kHz); 30 mA peak (at 1 MHz)
• **Output Impedance:** 50 ohms
• **Hum and Noise:** <0.5 mV RMS (100 kHz bandwidth); 2 mV RMS (10 MHz bandwidth); 2–5 mV RMS (X100 band, high-pass mode)
• **Output DC Stability:** ±1 mV/hour; ±1 mV/°C
• **Distortion:** <0.1% (typical across range)
• **Calibration Accuracy:** ±2%
• **Filter Response:** Four-pole Butterworth (maximally flat) or four-pole RC (damped)
• **Maximum AC Input Voltage:** ±1 V peak (0 dB gain); ±0.7 V peak (20 dB gain)
• **Maximum DC Input Voltage:** ±100 V
• **Input Impedance:** 10 ohms

## Key Features

• Dual isolated channels enable parallel or series cascading for band-reject or band-pass operation
• Selectable RC or Butterworth response optimizes for time-domain or frequency-domain performance
• Decade-switch tuning with multiplier provides direct frequency setting without lookup tables
• Low output impedance (50 ohms) drives high-impedance loads and distribution networks

## Typical Applications

• Audio and vibration signal conditioning
• Precision measurement preprocessing
• Multi-channel test signal filtering
• Transient-optimized filtering (RC mode) or flat-passband filtering (Butterworth mode)

## Compatibility & Integration

Dual isolated channels with independent connectors integrate into rack systems and bench setups. ±100 V DC maximum input rating accommodates transducer outputs and signal sources across industrial and laboratory environments.