NXP Semiconductors introduced the GreenChip TEA1708 an automatic discharge IC for X capacitors with an extremely low power consumption of 1 mW at 230 V (AC). Power supplies have traditionally relied on resistive discharge for X capacitors, which are used to reduce EMI (electromagnetic interference). By automatically discharging the X capacitor when the power supply is disconnected from the mains, the TEA1708 reduces power consumption by 20 – 30 mW, compared to using resistive discharge.
In addition to the automatic discharge functionality, the TEA1708 integrates a 500 V clamping circuit, protecting the IC during mains surges and making the device very rugged. To protect the TEA1708, no additional metal-oxide varistor (MOV) is required. In a typical application with only two 200 kΩ resistors, the maximum differential mode mains surge voltage allowed exceeds 6 kV. The breakthrough reduction in power consumption achieved by the TEA1708 – combined with its extreme ruggedness in withstanding power surges – make it a compelling solution for power supply manufacturers aiming to comply with new regulatory requirements such as Version 5 of the Code of Conduct (CoC) for External Power Supplies (EPS) and the amended ErP Lot 6, both introduced by the European Commission earlier this year.
Key Features of the TEA1708
- Nemko certified for compliance with IEC 60950-1
- Ultra-low 1 mW power consumption at 230 V (AC)
- Integrated 500 V clamp; no metal oxide varistor required to protect the IC
- Self supplied, no external bias requiredDischarge current internally limited to 2.3 mA, supporting use of large-value X capacitors
- Adjustable discharge delay timer using an external low-voltage capacitor
- Very high differential surge: 6 kV with two 200 kΩ resistors
- Easier application design, resolving EMI issues while retaining the efficiency level
