SLUSES3B
October 2023 – July 2024
UCC25660
PRODUCTION DATA
1
1
Features
2
Applications
3
Description
4
Device Comparison Table
5
Pin Configuration and Functions
6
Specifications
6.1
Absolute Maximum Ratings
6.2
ESD Ratings
6.3
Recommended Operating Conditions
6.4
Thermal Information
6.5
Electrical Characteristics
6.6
Switching Characteristics
6.7
Typical Characteristics
7
Detailed Description
7.1
Overview
7.2
Functional Block Diagram
7.3
Feature Description
7.3.1
Input Power Proportional Control
7.3.1.1
Voltage Feedforward
7.3.2
VCR Synthesizer
7.3.3
Feedback Chain (Control Input)
7.3.4
Adaptive Dead-Time
7.3.5
Input Voltage Sensing
7.3.5.1
Brown in and Brown out Tresholds and Options
7.3.5.2
Output OVP and External OTP
7.3.6
Resonant Tank Current Sensing
7.4
Protections
7.4.1
Zero Current Switching (ZCS) Protection
7.4.2
Minimum Current Turn-off During Soft Start
7.4.3
Cycle by Cycle Current Limit and Short Circuit Protection
7.4.4
Overload (OLP) Protection
7.4.5
VCC OVP Protection
7.5
Device Functional Modes
7.5.1
Startup
7.5.1.1
With HV Startup
7.5.1.2
Without HV Startup
7.5.2
Soft Start Ramp
7.5.2.1
Startup Transition to Regulation
7.5.3
Light Load Management
7.5.3.1
Operating Modes (Burst Pattern)
7.5.3.2
Mode Transition Management
7.5.3.3
Burst Mode Threshold Programming
7.5.3.4
PFC On/Off
7.5.4
X-Capacitor Discharge
7.5.4.1
Detecting Through HV Pin Only
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 Power Stage Requirements
8.2.2.2
LLC Gain Range
8.2.2.3
Select Ln and Qe
8.2.2.4
Determine Equivalent Load Resistance
8.2.2.5
Determine Component Parameters for LLC Resonant Circuit
8.2.2.6
LLC Primary-Side Currents
8.2.2.7
LLC Secondary-Side Currents
8.2.2.8
LLC Transformer
8.2.2.9
LLC Resonant Inductor
8.2.2.10
LLC Resonant Capacitor
8.2.2.11
LLC Primary-Side MOSFETs
8.2.2.12
Design Considerations for Adaptive Dead-Time
8.2.2.13
LLC Rectifier Diodes
8.2.2.14
LLC Output Capacitors
8.2.2.15
HV Pin Series Resistors
8.2.2.16
BLK Pin Voltage Divider
8.2.2.17
ISNS Pin Differentiator
8.2.2.18
TSET Pin
8.2.2.19
OVP/OTP Pin
8.2.2.20
Burst Mode Programming
8.2.2.21
Application Curves
8.3
Power Supply Recommendations
8.3.1
VCCP Pin Capacitor
8.3.2
Boot Capacitor
8.3.3
V5P Pin Capacitor
8.4
Layout
8.4.1
Layout Guidelines
8.4.2
Layout Example
8.4.2.1
Schematics
8.4.2.2
Schematics
9
Revision History
10
Mechanical, Packaging, and Orderable Information
7.5.4.1
Detecting Through HV Pin Only
Figure 7-21
Zero Cross Detection Sequence HV Pin Only
Figure 7-22
AC ZCD and X-Capacitor Discharge Flow Chart
Once every 700ms, the HV pin zero cross detection circuit gets engaged.
At first, HV pin test current is zero and the duration is 12ms. HV pin voltage is checked to see if the voltage is less than 9V threshold
If HV pin voltage does not falls below 9V, apply test current I1, and check again if HV pin voltage is less than 9V threshold
If HV pin voltage still not falls below 9V, continue to increase test current to I2 and then I3, I4
I4 test current's maximum on time is 36ms
If the HV pin voltage does not fall below 9V even after I4, the X-Cap discharge circuit is engaged for 360ms.
The minimal interval between two test current events is 700ms