1 Features
• Functional Safety-Capable
– Documentation available to aid functional safety
system design
• Voltage-sense, current-inject active EMI filter
– Optimized for CISPR 11 and CISPR 32 Class B
conducted EMI requirements
– Low impedance for common-mode emissions
over the applicable EMI frequency range (150
kHz to 3 MHz)
– 50%+ reduction in choke size, weight and cost
– Peak inject current of ±80 mA (typical)
– Amplifier with unity gain bandwidth of 113 MHz
• Wide supply voltage range of 8 V to 16 V
• Junction temperature range of –40°C to 150°C
• Simple external configuration for single-phase AC
power systems
– Integrated sensing filter and summing network
– Low leakage current at line frequency
– Simplified compensation network
• Inherent protection features for robust design
– Withstands surge of 5 kV (IEC 61000-4-5) with
minimal external component count
– Enable pin for remote ON and OFF control
– VDD voltage UVLO protection with hysteresis
– Thermal shutdown protection with hysteresis
• 4.2-mm × 2-mm SOT-23 14-pin (DYY) package

2 Applications
• Power delivery – high-density server PSUs
• HVAC motor control, aerospace and defense
• Welders, inverters and other industrial systems
• Telecom AC/DC rectifiers

3 Description
The TPSF12C1 is an active filter IC designed
to reduce common-mode (CM) electromagnetic
interference (EMI) in single-phase AC power systems.
The active EMI filter (AEF) configured with voltage
sense and current inject (VSCI) uses a capacitive
multiplier circuit to emulate the Y-capacitors in a
conventional passive filter design. The device senses
the high-frequency noise on each power line using a
set of sense capacitors and injects noise-canceling
currents back into the power lines using an injection
capacitor. The effective active capacitance is set by
the circuit gain and the injection capacitance. The
AEF sensing and injection impedances use relatively
low capacitance values with small component
footprints. The device includes integrated filtering,
compensation and protection circuitry, and an enable
input.
The TPSF12C1 provides a very low impedance path
for CM noise in the frequency range of interest for
EMI measurement. Enabling up to 30 dB of CM noise
reduction at the lower end of specified frequency
ranges (for example, 150 kHz to 3 MHz) significantly
reduces the size, weight and cost of the CM filter
implementation.