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.