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.