SLUSC18A
September 2014 – March 2015
UCC29950
PRODUCTION DATA.
1
Features
2
Applications
3
Description
4
Revision History
5
Pin Configuration and Functions
5.1
Detailed Pin Descriptions
5.1.1
VCC
5.1.2
MD_SEL/PS_ON
5.1.3
SUFG, SUFS
5.1.4
GD1, GD2
5.1.5
GND
5.1.6
AGND
5.1.7
LLC_CS
5.1.8
FB
5.1.9
PFC_GD
5.1.10
PFC_CS
5.1.11
VBULK
5.1.12
AC1, AC2
5.1.13
AC_DET
6
Specifications
6.1
Absolute Maximum Ratings
6.2
Storage Conditions
6.3
ESD Ratings
6.4
Recommended Operating Conditions
6.5
Thermal Information
6.6
Electrical Characteristics
6.7
Typical Characteristics
7
Detailed Description
7.1
Overview
7.2
Functional Block Diagram
7.3
Feature Description
7.3.1
Sense Networks
7.3.2
Sense Network Fault Detection
7.3.3
PFC Stage Soft-Start
7.3.4
AC Line Voltage Sensing
7.3.5
VBLK Sensing
7.3.6
AC Input UVLO and Brownout Protection
7.3.7
Dither
7.3.8
Active X-Cap Discharge
7.3.9
LLC Stage Soft Start
7.3.10
PFC Stage Current Sensing
7.3.11
Input Power Limit
7.3.12
PFC Stage Soft Start
7.3.13
Hybrid PFC Control Loop
7.3.14
PFC Stage Second Current Limit
7.3.15
PFC Inductor and Bulk Capacitor Recommendations
7.3.16
PFC Stage Over Voltage Protection
7.3.17
LLC Stage Control
7.3.18
Driver Output Stages and Characteristic
7.3.19
LLC Stage Dead Time Profile
7.3.20
LLC Stage Current Sensing
7.3.21
LLC Three Level Over-Current Protection
7.3.22
Over-Temperature Protection
7.3.23
Fault Timer and Control
7.4
Device Functional Modes
7.4.1
Mode Selection
7.4.2
Start-Up in Aux Bias Mode
7.4.3
Start-Up Operation in Self-Bias Mode
7.4.4
Bias Rail UVLO
7.4.5
LLC Stage MOSFET Drive
7.4.6
Gate Drive Transformer
7.4.7
Gate Drive Device
7.4.8
Comparison
8
Application and Implementation
8.1
Application Information
8.2
Typical Application
8.2.1
Design Requirements
8.2.2
Detailed Design Procedure
8.2.2.1
LLC Stage
8.2.2.2
LLC Switching Frequency
8.2.2.3
LLC Transformer Turns Ratio
8.2.2.4
LLC Stage Equivalent Load Resistance
8.2.2.5
LLC Gain Range
8.2.2.6
Select LN and QE
8.2.2.7
LLC No-Load Gain
8.2.2.8
Parameters of the LLC Resonant Circuit
8.2.2.9
Verify the LLC Resonant Circuit Design
8.2.2.10
LLC Primary-Side Currents
8.2.2.11
LLC Secondary-Side Currents
8.2.2.12
LLC Transformer
8.2.2.13
LLC Resonant Inductor
8.2.2.14
Combining the LLC Resonant Inductor and Transformer
8.2.2.15
LLC Resonant Capacitor
8.2.2.16
LLC Stage with Split Resonant Capacitor
8.2.2.17
LLC Primary-Side MOSFETs
8.2.2.18
LLC Output Rectifier Diodes
8.2.2.19
LLC Stage Output Capacitors
8.2.2.20
LLC Stage Over-Current Protection, Current Sense Resistor
8.2.2.21
Detailed Design Procedure for the PFC stage
8.2.2.22
PFC Stage Output Current Calculation
8.2.2.23
Line Current Calculation
8.2.2.24
Bridge Rectifier
8.2.2.25
PFC Boost Inductor
8.2.2.26
PFC Input Capacitor
8.2.2.27
PFC Stage MOSFET
8.2.2.28
PFC Boost Diode
8.2.2.29
Bulk Capacitor
8.2.2.30
PFC Stage Current Sense Resistor
8.2.3
Application Curves
8.3
Do's and Don'ts
9
Power Supply Recommendations
10
Layout
10.1
Layout Guidelines
10.1.1
GND Pin
10.1.2
GD1, GD2 Pins
10.1.3
VCC Pin
10.1.4
SUFG Pin
10.1.5
SUFS Pin
10.1.6
AGND Pin
10.1.7
MD_SEL/PS_ON Pin
10.1.8
VBULK Pin
10.1.9
AC1, AC2 Pins
10.1.10
LLC_CS
10.1.11
FB
10.1.12
PFC_CS
10.1.13
AC_DET
10.1.14
PFC_GD
10.2
Layout Example
11
Device and Documentation Support
11.1
Documentation Support
11.1.1
Related Documentation
11.2
Trademarks
11.3
Electrostatic Discharge Caution
11.4
Glossary
12
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
D|16
MPDS178G
Thermal pad, mechanical data (Package|Pins)
Orderable Information
slusc18a_oa
slusc18a_pm