Low-pass electronic filter QPI™

activeopen-framesurface-mount

Overview
The QPI family of active EMI filters provides conducted common-mode (CM) and differential-mode (DM) attenuation from 150 kHz to 30 MHz (CISPR22 range). The proprietary active-filtering circuit delivers superior low‑frequency attenuation to support EN55022/EN55032 (Class B) limits and PICMG 3.0 for ATCA boards. Active filtering reduces the volume of the common‑mode choke, enabling a low‑profile surface‑mount device that saves PCB area and improves airflow in blade and high‑density systems.

Key product notes
The MQPI-18 variant attenuates conducted CM and DM noise for 28 V input MIL PRMs to meet MIL‑STD‑461F conducted noise requirements. The MQPI-18 operates across the full input range of a 28 V MIL PRM and supports 7 A loads up to 85°C ambient without derating.

Features and benefits

• Conducted CM and DM attenuation from 150 kHz to 30 MHz (CISPR22 range)
• Optimized for applications requiring EN55022/EN55032 Class B limits and PICMG 3.0 for ATCA
• Available nominal input voltages: 12 V, 24 V and 48 V families (model dependent)
• Active filtering significantly reduces common‑mode choke size — low‑profile, surface‑mount form factor
• Saves up to 50% PCB area vs. standard passive filters and improves airflow in blade applications

Available parts (summary table)
Part Number | Input (V) | Current (A) | Test Freq. (kHz) | CM Attenuation (dB) | HIPot (V) | Package
QPI-21LZ-01 | 30 – 80 | 14 | 250 | 45 | 1,500 | Open Frame
QPI-21LZ | 30 – 80 | 14 | 250 | 45 | 1,500 | LGA
QPI-12LZ-01 | 5.0 – 80 | 7 | 1,000 | 40 | 1,500 | Open Frame
QPI-12LZ | 5.0 – 80 | 7 | 1,000 | 40 | 1,500 | LGA
QPI-11LZ-01 | 5.0 – 50 | 7 | 1,000 | 60 | 707 | Open Frame
QPI-11LZ | 5.0 – 50 | 7 | 1,000 | 60 | 707 | LGA
QPI-6LZ-01 | 30 – 80 | 14 | 250 | 40 | 1,500 | Open Frame
QPI-6LZ | 30 – 80 | 14 | 250 | 40 | 1,500 | LGA
QPI-5LZ-01 | 10 – 40 | 14 | 250 | 60 | 707 | Open Frame
QPI-5LZ | 10 – 40 | 14 | 250 | 60 | 707 | LGA
QPI-3LZ-01 | 10 – 40 | 7 | 250 | 65 | 707 | Open Frame
QPI-3LZ | 10 – 40 | 7 | 250 | 65 | 707 | LGA
MQPI-18LP-01 | 5.0 – 50 | 7 | 1,000 | 45 | 1,500 | Open Frame
MQPI-18LP | 5.0 – 50 | 7 | 1,000 | 45 | 1,500 | LGA

Resources and related documentation (examples)

• Datasheets, evaluation board user guides and application notes for QPI, QPO and MQPI variants
• Mechanical STEP models and integration guides for LGA and Open Frame packages
• White paper on active filtering and EMI control (selection and board‑level integration)

Technical specifications

• Conducted CM and DM attenuation: 150 kHz – 30 MHz (CISPR22 range)
• Targeted optimization: EN55022/EN55032 Class B; supports PICMG 3.0 for ATCA
• Typical CM attenuation by part: up to 65 dB (see per‑part table)
• Input ranges: model dependent (examples: 5.0–50 V, 5.0–80 V, 10–40 V, 30–80 V)
• Current ratings: 7 A and 14 A variants
• HIPot ratings: 707 V or 1,500 V depending on model
• Package options: Open Frame and LGA (low‑profile surface‑mount)
• MIL variant (MQPI-18): complies with MIL‑STD‑461F conducted noise requirements for 28 V PRMs; supports 7 A to 85°C TA without derating
• Benefits: reduced choke volume, lower profile, PCB area savings, improved airflow for blade and high‑density systems