NXP Semiconductors UM10525 User manual

UM10525
120 V 20 W CFL demo board using the UBA2212
Rev. 1 — 19 April 2012 User manual
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Keywords UBA2212, demo board, CFL, boost, 120 V (AC), 20 W
Abstract This document is a user manual for the UBA2212 120 V, 20 W demo
board

UM10525 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2012. All rights reserved.
User manual Rev. 1 — 19 April 2012 2 of 21
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For more information, please visit: http://www.nxp.com
For sales office addresses, please send an email to: [email protected]
NXP Semiconductors UM10525
120 V 20 W CFL demo board using the UBA2212
Revision history
Rev Date Description
v.1 20120419 first issue

UM10525 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2012. All rights reserved.
User manual Rev. 1 — 19 April 2012 3 of 21
NXP Semiconductors UM10525
120 V 20 W CFL demo board using the UBA2212
1. Introduction
The UBA2212 series is a family of high voltage monolithic integrated circuits for driving
Compact Fluorescent Lamps (CFL) in half-bridge configurations. It is derived from the
UBA2211 IC and modified to drive a 120 V (AC) application. The UBA2212 contains a
boost feature, which boosts the lamp current for a certain time after ignition. This feature
results in faster CFL warm-up and more light after ignition.
Run-up time is one of the key requirements for CFL. Normally, it is measured from the
time lamp was powered until 80 % of light output is reached. Run-up time is long if a high
temperature amalgam burner is used or a lamp is ignited in cold environment. The
UBA2212 is designed to meet the needs of these situations in both indoor and outdoor
applications.
In addition to the boost feature, the UBA2212 has the following features:
•Fixed frequency preheat with an adjustable preheat time
•RMS current control
•Saturation Current Protection (SCP)
•OverTemperature Protection (OTP)
•Capacitive Mode Protection (CMP)
This user manual is intended to describe a 120 V, 20 W application demo board using the
UBA2212CT. See the UBA2212 data sheet for the functional description of this IC.

UM10525 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2012. All rights reserved.
User manual Rev. 1 — 19 April 2012 4 of 21
NXP Semiconductors UM10525
120 V 20 W CFL demo board using the UBA2212
2. Safety Warning
The demo board is powered by AC mains voltage. Avoid touching the board when power
is applied. An isolated housing is obligatory when used in uncontrolled, non-laboratory
environments. Always provide galvanic isolation of the mains phase using a variable
transformer. The following symbols identify isolated and non-isolated devices.
WARNING
Lethal voltage and fire ignition hazard
The non-insulated high voltages that are present when operating this product, constitute a
risk of electric shock, personal injury, death and/or ignition of fire.
This product is intended for evaluation purposes only. It shall be operated in a designated test
area by personnel qualified according to local requirements and labor laws to work with
non-insulated mains voltages and high-voltage circuits. This product shall never be operated
unattended.
a. Isolated b. Non-isolated
Fig 1. Isolated and non-isolated symbols
019aab173
019aab174

UM10525 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2012. All rights reserved.
User manual Rev. 1 — 19 April 2012 5 of 21
NXP Semiconductors UM10525
120 V 20 W CFL demo board using the UBA2212
3. Specifications
Table 1. Demo board specification
Parameter State Value Comment
AC line input voltage - 96 V (AC) to 144 V (AC) board optimized for 120 V (AC), 60 Hz.
Lamp voltage (Vlamp) steady 100 V measured at 120 V (AC) mains; GE T3 Spiral 20 W
burner used; Table 2 on page 10
Lamp current (Ilamp)170mA
Operating frequency
(fosc)45 kHz
Power Factor >0.58
Preheat current (Iph) preheat 150 mA constant preheat current at 96 V (AC) to 144 V (AC);
Table 2 on page 10
Preheat time (tph)0.8s
Lamp current (Ilamp) boost 255 mA measured at 120 V (AC) mains; see Figure 5 on page 8
and Table 2 on page 10
boost time (tbst)40s
transition time from boost
to burn (tt(bst-burn))2s
Fig 2. Photographs of a 20 W CFL Application with a UBA2212

UM10525 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2012. All rights reserved.
User manual Rev. 1 — 19 April 2012 6 of 21
NXP Semiconductors UM10525
120 V 20 W CFL demo board using the UBA2212
4. Schematic and functional description
4.1 Functional description
The bridge rectifier (D1 to D4) rectifies the AC input power. The bulk storage capacitor
CBUF filters the rectified DC voltage. Power inductor LFILT and capacitor CBUF form an LC
filter, which attenuates conducted differential mode EMI noise. Fusible resistor Rfuse
provides protection against overcurrent failure.
During start-up, the internal current source connected to HV pin provides power. Once
capacitor CDVDT is charged, it provides the dV/dt supply for normal operation. Capacitor
CFS provides the high-side floating supply output and Capacitor CVDD is used for VDD
bypass.
C5 and inductor L2 primary winding (N1) form an LC tank translating power into the
burner. The L2 secondary windings N2 and N3 preheat the burner filaments. If preheat is
not required in the application, leave off secondary windings and short the filaments. C8 is
DC blocking capacitor. RCSI is used for burner current sensing during boost and RMS
states.
Rosc and Cosc determine the nominal oscillating frequency based on the Built-in 555-timer
function. The input to the SW pin generates the VSW signal which determines the preheat
time. Capacitor CCB sets the boost time.
4.2 Timing
The UBA2212 based 20 W demo board provides all the functions needed for correct CFL
operation. These functions include preheat, ignition, boost and on-state operation.
Several protection features safeguard the correct operation of the CFL and controller IC.
The typical system timing is shown in Figure 4.
Fig 3. Typical UBA2212 Circuit for compact fluorescent lamp application
001aan371
Rfuse
D3
CBUF
C5 C8
C7
C6
L2
RCSI
CDVDT
Cosc CCB
CVDD
Rosc
CSW
CFS
LFILT
D2
D4D1
U1
OUT 114 FS
SGND 213 SGND
HV 312 SENSE
PGND 411 SGND
DVDT 510 CSI
VDD 69
CB
RC 78 SW
CFL
AC input
L_N
L_L
UBA2212

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User manual Rev. 1 — 19 April 2012 7 of 21
NXP Semiconductors UM10525
120 V 20 W CFL demo board using the UBA2212
In preheat, current ISW charges capacitor CSW generate the preheat timing (tph).
Capacitor CCB connected to pin CB is connected to the boost timer input to control the
boost time. After preheat, the CCB voltage sweeps up and down at the boost timing (tbst).
The boost ends after 25 CCB sweeping cycles.
The transition from the boost state to the burn state is triggered when the boost timer
indicates the end of the boost state. During the boost to burn transition, the boost
transition timer is active. The timer defines transition time which is also realized using
capacitor CCB on CB pin.
When the RMS current control circuit leaves the system operating at the normal lamp
current, it enters the burn state. In this state, a feedback loop controls the VSW voltage on
pin SW. This feature makes the lamp current independent mains or lamp voltage
variations.
Fig 4. Timing sequence of the system
001aan302
preheat
V
CB
V
SW
VCO input
burn
time (s)
ignition and boost
transition
V
lamp
f
osc(nom)
... ...

UM10525 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2012. All rights reserved.
User manual Rev. 1 — 19 April 2012 8 of 21
NXP Semiconductors UM10525
120 V 20 W CFL demo board using the UBA2212
5. Measurement results
Using a typical 20 W lamp, the measurements show that the boost effect is visible to the
human eye when the light is powered up. The same situation is not visible when the same
lamp is used without boost feature.
Figure 4 shows the states after power-on. The preheat, ignition, boost, transition and burn
states are clearly visible. The preheat and transition states are also zoomed in greater
detail.
(1) Ilamp signal.
(2) SW signal timing for preheat.
(3) CB signal timing for boost and transition.
(4) Half-bridge voltage.
Fig 5. Time sequence for a boost state lamp

UM10525 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2012. All rights reserved.
User manual Rev. 1 — 19 April 2012 9 of 21
NXP Semiconductors UM10525
120 V 20 W CFL demo board using the UBA2212
(1) Ilamp signal.
(2) SW signal timing for preheat.
(3) CB signal timing for boost and transition.
(4) Half-bridge voltage.
Fig 6. Time sequence for a boost lamp with a zoom function applied to the preheat state
(1) Ilamp signal.
(2) SW signal timing for preheat.
(3) CB signal timing for boost and transition
(4) Half-bridge voltage.
Fig 7. Time sequence for a boost lamp with a zoom function applied to the preheat to
RMS transition

UM10525 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2012. All rights reserved.
User manual Rev. 1 — 19 April 2012 10 of 21
NXP Semiconductors UM10525
120 V 20 W CFL demo board using the UBA2212
The boost feature provides a fast run-up time. However when a hot lamp is powered, the
lamp does not need boost or only a short boost time. The UBA2212 sets a boost
overtemperature (Tj(end)bst) to allow for the reduced boost time. The IC detects its die
temperature and ends the boost state when the temperature trigger point is reached. The
lamp then enters the burn transition.
When a lamp burns for a long time, is switched off and then after a short delay switched
on again. The end of boost is reached after only 6 s of boost. In Figure 5, SW counted
only 5 cycles. Normally SW sweeps through 25 cycles when OTP is not triggered.
Table 2. Electrical parameters 12 W boost lamp (UBA2212BT N1B)
Boost ratio = 1.49; boost time = 38.5 s (25 cycles); transition time = 2 s.
State VIN
(V) Pin (W) PF Vlamp (V) IIamp (mA) Ihb (mA) Plamp (W) fosc (kHz) Tph (s) Iph (mA)
Normal 120 21.3 0.589 107 169 366 18.1 44.3 0.76 150
Boost - 23.1 - 80.5 252 470 20.3 39.7 - -
(1) Ilamp signal.
(2) SW signal timing for preheat.
(3) Half-bridge voltage.
(4) CB signal timing for boost and transition.
Fig 8. Boost with OTP triggered