NXP Semiconductors AN10907, Application Note

Page: 82 / 82

NXP Semiconductors
AN10907
TEA1613T resonant power supply control IC
© NXP B.V. 2010. All rights reserved.
For more information, please visit: http://www.nxp.com
For sales office addresses, please send an email to: salesaddresses@nxp.com
Date of release: 28 December 2010
Document identifier: AN10907
Please be aware that important notices concerning this document and the product(s)
described herein, have been included in section ‘Legal information’.
8.7.1 HBC overcurrent regulation . . . . . . . . . . . . . . 44
8.7.2 HBC overcurrent protection . . . . . . . . . . . . . . 45
8.7.3 SNSCURHBC boost voltage compensation . . 45
8.7.4 Current measurement circuits. . . . . . . . . . . . . 46
8.7.5 SNSCURHBC layout . . . . . . . . . . . . . . . . . . . 46
9 Burst mode operation . . . . . . . . . . . . . . . . . . . 47
9.1 Burst mode implementation . . . . . . . . . . . . . . 47
9.2 PFC burst mode operation control by
SNSOUT/PFCON . . . . . . . . . . . . . . . . . . . . . . 48
9.3 Advantages of burst mode in HBC . . . . . . . . . 49
9.4 Advantages of burst mode for HBC and PFC
simultaneously . . . . . . . . . . . . . . . . . . . . . . . . 50
9.5 Choice of burst level and divider impedance . 51
9.5.1 Basic design of an SNSBURST circuit . . . . . . 51
9.5.2 Advanced design of SNSBURST circuit . . . . . 52
9.5.3 Advanced design of SNSBURST circuit
using a series resistor. . . . . . . . . . . . . . . . . . . 53
9.5.4 Other aspects regarding SNSBURST. . . . . . . 54
9.6 Output power - operating frequency
characteristics. . . . . . . . . . . . . . . . . . . . . . . . . 55
9.7 Lower SUPHS in burst . . . . . . . . . . . . . . . . . . 56
9.8 Audible noise . . . . . . . . . . . . . . . . . . . . . . . . . 56
9.8.1 Measurements in the resonant transformer
construction . . . . . . . . . . . . . . . . . . . . . . . . . . 56
9.8.2 Burst power dependent noise level . . . . . . . . 57
9.9 PFC converter and resonant converter
simultaneous bursting. . . . . . . . . . . . . . . . . . . 57
9.9.1 PFC start delay . . . . . . . . . . . . . . . . . . . . . . . . 57
9.9.2 PFC output voltage variations. . . . . . . . . . . . . 57
9.9.3 Switching between burst and normal
operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
9.9.4 Audible noise during mode transition . . . . . . . 58
9.10 Design guidelines for burst mode operation . . 58
9.11 Enable/disable burst mode . . . . . . . . . . . . . . . 58
9.12 Hold HBC and PFC . . . . . . . . . . . . . . . . . . . . 58
9.13 Unused burst mode . . . . . . . . . . . . . . . . . . . . 58
10 Protection functions . . . . . . . . . . . . . . . . . . . . 59
10.1 Protection overview . . . . . . . . . . . . . . . . . . . . 59
10.2 IC protection . . . . . . . . . . . . . . . . . . . . . . . . . . 59
10.2.1 OverTemperature Protection (OTP) . . . . . . . . 59
10.2.2 Latched protection . . . . . . . . . . . . . . . . . . . . . 59
10.3 SNSOUT/PFCON protection . . . . . . . . . . . . . 60
10.3.1 OverVoltage Protection (OVP) output. . . . . . . 60
10.3.1.1 Auxiliary winding . . . . . . . . . . . . . . . . . . . . . . . 60
10.3.1.2 Principle of operation . . . . . . . . . . . . . . . . . . . 60
10.3.1.3 Connecting external measurement circuits. . . 60
10.3.2
UnderVoltage Protection (UVP) output . . . . . . 61
10.3.2.1 Auxiliary winding . . . . . . . . . . . . . . . . . . . . . . . 61
10.3.2.2 Principle of operation . . . . . . . . . . . . . . . . . . . 61
10.3.2.3 Connecting external measurement circuits. . . 61
10.3.3 OVP and UVP combinations . . . . . . . . . . . . . 61
10.3.3.1 Circuit configurations . . . . . . . . . . . . . . . . . . . 61
10.3.3.2 OVP
functionality and UVP disabled . . . . . . . 62
10.3.3.3 UVP functionality and OVP disabled . . . . . . . 62
10.3.3.4 Both OVP and UVP disabled . . . . . . . . . . . . . 63
10.3.3.5 UVP during burst mode operation . . . . . . . . . 63
10.4
Protection timer . . . . . . . . . . . . . . . . . . . . . . . 64
10.4.1 Block diagram of the RCPROT function . . . . 64
10.4.1.1 RCPROT working as protection timer . . . . . . 64
10.4.2
RCPROT working as a restart timer. . . . . . . . 65
10.4.3 Dimensioning the timer function. . . . . . . . . . . 66
11 Miscellaneous advice and tips. . . . . . . . . . . . 67
11.1 PCB layout . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
11.1.1 Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
11.1.2 Large current loops . . . . . . . . . . . . . . . . . . . . 67
11.1.3 Ground layout example . . . . . . . . . . . . . . . . . 68
11.1.4 Miscellaneous . . . . . . . . . . . . . . . . . . . . . . . . 68
11.2 Starting/debugging partial circuits . . . . . . . . . 69
11.2.1 HBC only . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
12 Application examples and topologies. . . . . . 73
12.1 Example of IC evaluation and test setup . . . . 73
12.2 Example of a 250 W LCD-TV application . . . 74
13 Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . 78
14 Legal information . . . . . . . . . . . . . . . . . . . . . . 79
14.1 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
14.2 Disclaimers . . . . . . . . . . . . . . . . . . . . . . . . . . 79
14.3 Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . 79
15 Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
16 Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
17 Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82