General description

The UBA20271/2 are high-voltage power ICs intended to drive and control higher powered self ballasted Compact Fluorescent Lamp (CFL) lighting applications. The UBA20271/2 operate from 120 V and 230 V. The module includes a half-bridge power circuit of two NMOST power FETs. In addition, a controller circuit is included that has advanced features for dimming and a lamp current controlled boost feature. The boost feature is used for boosting cold (amalgam) CFL.

The controller contains a half-bridge drive function for CFL, a high-voltage level-shift circuit with integrated bootstrap diode. In addition, the controller contains an oscillator function, a current control function both for preheat and burn, a timer function and protection circuits. The UBA20271/2 are supplied via a dV/dt current charge supply circuit from the half-bridge circuit.

Remark: Mains voltages noted are AC.

Features and benefits

2.1Half-bridge features

?UBA20271: Two internal 350 V, 1.0 ?? max 5.0 A NMOST half-bridge power FETs

?UBA20272: Two internal 600 V, 3.0 ?, max 2.7 A NMOST half-bridge power FETs

?Integrated high-voltage level-shift function with integrated bootstrap diode

2.2Preheat and ignition features

?Coil saturation protection during ignition

?Adjustable saturation protection level

?Adjustable preheat time

?Adjustable preheat current

?Ignition lamp current detection

2.3Lamp boost features

?Adjustable boost timing

?Fixed boost current ratio of 1.5

?Gradually boost to burn transition timing

2.4Dim features

?Continuously variable dimming function for standard phase cut dimmers

?Natural dimming curve by logarithmic correction

?Adjustable Minimum Dimming Level (MDL)

?Controlled lamp ON/OFF

2.5Protection

?OverCurrent Protection (OCP) in boost and burn state

?Capacitive Mode Protection (CMP)

?OverPower Protection (OPP)

?Power-down function

?OverTemperature Protection (OTP)

2.6Other features

?Current controlled operating in boost and burn state

?External power-down function

?Lamp flicker suppression

Applications

?Dimmable compact fluorescent lamps for power levels from 5 W to 20 W directly operating from 230 V (UBA20272) and 120 V (UBA20271) mains voltage.