SLUS157Q
December 1999 – October 2019
UCC1895
,
UCC2895
,
UCC3895
PRODUCTION DATA.
1
Features
2
Applications
3
Description
Device Images
Simplified Application Diagram
4
Revision History
5
Pin Configuration and Functions
Pin 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
Typical Characteristics
7
Detailed Description
7.1
Overview
7.2
Functional Block Diagrams
7.3
Feature Description
7.3.1
ADS (Adaptive Delay Set)
7.3.2
CS (Current Sense)
7.3.3
CT (Oscillator Timing Capacitor)
7.3.4
DELAB and DELCD (Delay Programming Between Complementary Outputs)
7.3.5
EAOUT, EAP, and EAN (Error Amplifier)
7.3.6
OUTA, OUTB, OUTC, and OUTD (Output MOSFET Drivers)
7.3.7
PGND (Power Ground)
7.3.8
RAMP (Inverting Input of the PWM Comparator)
7.3.9
REF (Voltage Reference)
7.3.10
RT (Oscillator Timing Resistor)
7.3.11
GND (Analog Ground)
7.3.12
SS/DISB (Soft Start/Disable)
7.3.13
SYNC (Oscillator Synchronization)
7.3.14
VDD (Chip Supply)
7.4
Device Functional Modes
7.5
Programming
7.5.1
Programming DELAB, DELCD and the Adaptive Delay Set
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
Power Loss Budget
8.2.2.2
Preliminary Transformer Calculations (T1)
8.2.2.3
QA, QB, QC, QD FET Selection
8.2.2.4
Selecting LS
8.2.2.5
Selecting Diodes DB and DC
8.2.2.6
Output Inductor Selection (LOUT)
8.2.2.7
Output Capacitance (COUT)
8.2.2.8
Select Rectifier Diodes
8.2.2.9
Input Capacitance (CIN)
8.2.2.10
Current Sense Network (CT, RCS, RR, DA)
8.2.2.10.1
Output Voltage Setpoint
8.2.2.10.2
Voltage Loop Compensation
8.2.2.10.3
Setting the Switching Frequency
8.2.2.10.4
Soft Start
8.2.2.10.5
Setting the Switching Delays
8.2.2.10.6
Setting the Slope Compensation
8.2.3
Application Curves
9
Power Supply Recommendations
10
Layout
10.1
Layout Guidelines
10.2
Layout Example
11
Device and Documentation Support
11.1
Documentation Support
11.1.1
Related Documentation
11.1.2
Related Links
11.2
Receiving Notification of Documentation Updates
11.3
Community Resource
11.4
Trademarks
11.5
Electrostatic Discharge Caution
11.6
Glossary
12
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
J|20
MGDI005
FK|20
MCQC028
Thermal pad, mechanical data (Package|Pins)
Orderable Information
slus157q_oa
slus157q_pm
7.3
Feature Description