AN11136_15 Datasheet, PDF (3/22 Pages) NXP Semiconductors – SSL2109T/AT/SSL2129AT controller for SSL applications

NXP Semiconductors
AN11136
SSL2109T/AT/SSL2129AT controller for SSL applications
1. Introduction
This application note discusses the specific external MOSFET design considerations for
the SSL2109T/AT and the SSL2129AT.
The SSL2109T/AT and SSL2129AT platforms are specifically defined to address the
market of retrofit SSL applications. It provides a controller, with an external high-voltage
switch. The devices are optimized to make cost-effective, highly efficient buck converter
solutions for high-voltage LED strings or LED modules. The buck converter is one of the
most used Switch Mode Power Supply (SMPS) topologies.
The application note “Buck converter for SSL applications” (AN10876) provides general
information about buck converter applications. The application note
“SSL21081/SSL21083/SSL2109 non-dimmable buck converter in low ripple configuration”
(AN11041) describes a step-by-step design procedure for non-mains dimmable
applications.
Information and design tools for this IC can be found on the product page on the NXP web
site.
1.1 Functional description
The SSL2109A/AT and the SSL2129AT are Multi-Chip Module (MCM) SO8 packages.
They can handle up to 600 V (DC) at pins HV and DRAIN. The main features for all
variants are as follows (See Figure 1 and Figure 2):
Switch-mode buck controller with power-efficient boundary conduction mode of operation
with:
• No reverse recovery losses in freewheel diode
• Zero Current Switching (ZCS) for switch-on of switch
• Zero voltage or valley switching for switch-on of switch
• Smallest possible inductance value and size
High Power Factor (> 0.9), depending on application
• Mains phase-cut dimmable using external components (SSL2109AT)
Fast transient response through cycle-by-cycle current control thus preventing:
• Overshoots and undershoots of the LED current
Internal protections:
• Undervoltage LockOut (UVLO)
• Leading-Edge Blanking (LEB)
• OverCurrent Protection (OCP)
• Short-Winding Protection (SWP; SSL2109T only)
• Internal overtemperature
• Brownout protection
• Output short protection
AN11136
Application note
All information provided in this document is subject to legal disclaimers.
Rev. 1.2 — 1 September 2014
© NXP Semiconductors N.V. 2014. All rights reserved.
3 of 22