General description
The TEA1708 is an automatic discharge IC for X capacitors with a low power consumption (typically 1 mW at 230 V (AC).
A 500 V clamping circuit is integrated, protecting the IC during mains surges. In a typical application with only two 200 kΩ resistors, the maximum differential mode mains surge voltage allowed exceeds 6 kV. A metal-oxide varistor is not required to protect the IC.
The X-capacitor discharge current is internally limited to 2.3 mA. The discharge delay timer is set externally using a low-voltage capacitor.
To reduce EMI while retaining the low standby power, the very low power consumption with a high discharge current enables the use of a high value X-capacitor.
FEATUREs and benefits
• 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 required
• Discharge current internally limited
• Adjustable discharge delay
• Very high differential surge: 6 kV with two 200 kΩ resistors
• Easier application design, resolving EMI issues while retaining the efficiency level
APPLICATIONs
• All AC-connected power supplies with X-capacitors > 100 nF requiring a low load standby power.