SLUSCK4B
September 2016 – December 2021
UCC28951-Q1
PRODUCTION DATA
1
Features
2
Applications
3
Description
4
Revision History
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
Timing Requirements
6.7
Dissipation Ratings
6.8
Typical Characteristics
7
Detailed Description
7.1
Overview
7.2
Functional Block Diagram
7.3
Feature Description
7.3.1
Start-Up Protection Logic
7.3.2
Voltage Reference (VREF)
7.3.3
Error Amplifier (EA+, EA–, COMP)
7.3.4
Soft-Start and Enable (SS/EN)
7.3.5
Light-Load Power Saving Features
7.3.6
Adaptive Delay, (Delay Between OUTA and OUTB, OUTC and OUTD (DELAB, DELCD, ADEL))
7.3.7
Adaptive Delay (Delay Between OUTA and OUTF, OUTB and OUTE (DELEF, ADELEF)
7.3.8
Minimum Pulse (TMIN)
7.3.9
Burst Mode
7.3.10
Switching Frequency Setting
7.3.11
Slope Compensation (RSUM)
7.3.12
Dynamic SR ON/OFF Control (DCM Mode)
7.3.13
Current Sensing (CS)
7.3.14
Cycle-by-Cycle Current Limit Current Protection and Hiccup Mode
7.3.15
Synchronization (SYNC)
7.3.16
Outputs (OUTA, OUTB, OUTC, OUTD, OUTE, OUTF)
7.3.17
Supply Voltage (VDD)
7.3.18
Ground (GND)
7.4
Device Functional Modes
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 FETs QE and QF
8.2.2.9
Input Capacitance (CIN)
8.2.2.10
Current Sense Network (CT, RCS, R7, DA)
8.2.2.10.1
Voltage Loop Compensation Recommendation
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
Device Support
11.1.1
Development Support
11.2
Documentation Support
11.2.1
Related Documentation
11.3
Receiving Notification of Documentation Updates
11.4
Community Resources
11.5
Trademarks
Package Options
Mechanical Data (Package|Pins)
PW|24
MPDS363A
Thermal pad, mechanical data (Package|Pins)
Orderable Information
slusck4b_oa
slusck4b_pm
1
Features
Qualified for automotive applications
AEC-Q100 qualified with the following results:
Device temperature grade 1: –40°C to +125°C ambient operating temperature range
Device HBM ESD classification level H2
Device CDM ESD classification level C3B
Enhanced zero-voltage switching (ZVS) range
Direct synchronous rectifier (SR) control
Light-load efficiency management including:
Burst mode operation
Discontinuous conduction mode (DCM), dynamic SR on/off control with programmable threshold
Programmable adaptive delay
Average- or peak-current mode control with programmable slope compensation and voltage-mode control
Closed-loop soft-start and enable function
Programmable switching frequency up to 1 MHz with bidirectional synchronization
(±3%) cycle-by-cycle current limit protection with hiccup mode support
150-µA start-up current
V
DD
undervoltage lockout
Wide temperature range: –40°C to +125°C