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.