NXP UBA2028 600V荧光灯调光方案

NXP公司的UBA2028是600V高压荧光灯(CFL)调光电路,包括有半桥输出的MOST,调光功能高压电平转移电路,振荡功能,灯电压监视器,电流控制功能和计时功能与保护功能. UBA2028具有两个600V 3欧姆MOST半桥功率电路,稳态电流高达280mA,起弧电流高达1.5A,可调整预热时间和预热电流,并采用电流控制, 主要用于5 W 到25 W 可调光的CFL.本文介绍了UBA2028的主要特性,方框图, PGND和GND的连接图, 120V和240V的应用电路图以及采用UBA2028 的CFL 18W 230V调光参考板主要特性,电路图和材料清单(BOM).

UBA2028: 600 V dimmable power IC for compact fluorescent lamps

The UBA2028 is a high voltage power IC that drives and controls electronically ballasted Compact Fluorescent Lamps (CFLs). The IC includes a Metal-Oxide-Semiconductor Transistor (MOST) half bridge power circuit, a dimming function, a high voltage level shift circuit, an oscillator function, a lamp voltage monitor, a current control function, a timer function and protections.

UBA2028主要特性:

• Two internal 600 V, 3ohm max MOST half bridge powers.

• For steady state currents up to 280 mA.

• For ignition currents up to 1.5 A.

• Adjustable preheat time.

• Adjustable preheat current.

• Current controlled operating.

• Single ignition attempt.

• Adaptive non-overlap time control.

• Integrated high voltage level shift function.

• Power-down function.

• Protection against lamp failures or lamp removal.

• Capacitive mode protection.

UBA2028应用:

• 5Wto 25W dimmable CFLs, provided that the maximum junction temperature is not exceeded.

图1.UBA2028方框图

图2.UBA2028 PGND和GND连接图

图3.UBA2028 120V应用电路图

图4.UBA2028 240V应用电路图

This application note describes how to design a dimmable Compact Fluorescent Lamp (CFL) with the UBA2028 or UBA2014. The difference between these two ICs is that the UBA2028 has integrated Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) (max RDSon = 3 ) and the UBA2014 has no integrated MOSFETs. With the internal MOSFETs, it is possible to drive burners up to 18 W. For larger burners, the UBA2014 with external MOSFETs must be used. The control part of both the UBA2014 and the UBA2028 are identical, so the same calculation tools can be used.

The design of a triac dimmable CFL is a complicated task because the dimming behavior is affected by interaction between the dimmer and CFL, tolerances, aging of components and, last but not least the circuit must not be expensive. Most components serve multiple purposes, so it is not always possible to choose the optimum value for each purpose. It is not known in advance which dimmer type the CFL will be connected to, so the designed circuit cannot be guaranteed to work with all dimmers.

图5.基本的230 V调光电路

图6.基本的CFL调光电路

图7.电荷泵CFL调光电路方框图

图8.带电荷泵功率反馈的CFL 逆变器框图
 
图9.UBA2014 230 V 电路图

图10.UBA2014 120 V 电路图

UBA2028 CFL 18W 230V调光参考板

UBA2028 CFL 18 W, 230 V dimmable reference board

The UBA2028 230 V mains dimmable reference board is a Compact Fluorescent Lamp (CFL) driver for a 18 W CFL burner. The maximum input power is 18 W, and it can be dimmed using a triac dimmer. The dimming range reaches down to 10 % of light output.

IC description

UBA2028 is a monolithic integrated circuit for driving electronically ballasted fluorescent lamps.The circuit is made in a 650 V Bipolar CMOS DMOS (BCD) power-logic process. It provides the drive function for the two discrete power MOSFETs. Besides the drive function, the IC also includes the level-shift circuit, the oscillator function, a lamp voltage monitor, a current control function, a timer function and protections.

The IC includes:

• Adjustable preheat time.

• Adjustable preheat current.

• Current controlled operating.

• Single ignition attempt.

• Adaptive non-overlap time control.

• Integrated high-voltage level-shift function.

• Power-down function.

• Protection against lamp failures or lamp removal.

• Capacitive mode protection.

Board description

Specification

This user manual describes the design of a 230 V mains dimmable CFL ballast solution that may be employed in an already existing triac based incandescent dimmer setup. The disadvantage of normal electronic ballasts is that they cannot be dimmed with a standard phase cut type of dimmer.

This is because in triac dimming, not only does the lamp current vary based on the triac position but also the supply voltage variation. Typically the triac conducts once it has been triggered and exceeds its latching current. and does not conduct when the current is less than the holding current. The dimmer works fine with a resistive load, such as an incandescent lamp. The triac can be triggered at any timing of the sinusoidal voltage (AC line input), and can be kept in conduction state until it reaches zero line voltage.

The dimmer solution is based on the UBA2028, which can be designed into a ballast application such that the load is dimmable with a standard (phase cut) type of dimmer.

The board is designed to drive a 18 W CFL burner for 230 V (AC) mains input. The 230 V (AC) reference board, it consists of AC mains input filter, rectifier, triac dimmer position detector, the lamp current detector, half bridge resonant tank and the charge pump circuit.

 
图11.UBA2028 CFL 18W 230V调光参考板


图12.UBA2028 230 V 电路图

材料清单(BOM):