SNVS657E
September 2010 – September 2014
LP8550
PRODUCTION DATA.
1
Features
2
Applications
3
Description
4
Revision History
5
Device Default Values
6
Pin Configuration and Functions
7
Specifications
7.1
Absolute Maximum Ratings
7.2
Handling Ratings
7.3
Recommended Operating Conditions
7.4
Thermal Information
7.5
Electrical Characteristics
7.6
Boost Converter Electrical Characteristics
7.7
LED Driver Electrical Characteristics
7.8
PWM Interface Characteristics
7.9
Undervoltage Protection
7.10
Logic Interface Characteristics
7.11
I2C Serial Bus Timing Parameters (SDA, SCLK)
7.12
Typical Characteristics
8
Detailed Description
8.1
Overview
8.2
Functional Block Diagram
8.3
Feature Description
8.3.1
Clock Generation
8.3.2
Brightness Control Methods
8.3.2.1
PWM Input Duty Cycle
8.3.2.2
Brightness Register Control
8.3.2.3
PWM Direct Control
8.3.2.4
PWM Calculation Data Flow
8.3.2.5
PWM Detector
8.3.2.6
Brightness Control
8.3.2.7
Resolution Selector
8.3.2.8
Sloper
8.3.2.9
PWM & Current Control
8.3.2.10
Dither
8.3.2.11
PWM Comparator
8.3.2.12
Current Setting
8.3.2.13
PWM Frequency Setting
8.3.2.14
Phase Shift PWM (PSPWM) Scheme
8.3.2.15
Slope and Dithering
8.3.2.16
Driver Headroom Control
8.3.3
Boost Converter
8.3.3.1
Operation
8.3.3.2
Protection
8.3.3.3
Manual Output Voltage Control
8.3.3.4
Adaptive Boost Control
8.3.4
Fault Detection
8.3.4.1
LED Fault Detection
8.3.4.2
Undervoltage Detection
8.3.4.3
Overcurrent Protection
8.3.4.4
Device Thermal Regulation
8.3.4.5
Thermal Shutdown
8.4
Device Functional Modes
8.5
Programming
8.5.1
I2C-Compatible Serial Bus Interface
8.5.1.1
Interface Bus Overview
8.5.1.2
Data Transactions
8.5.1.3
Acknowledge Cycle
8.5.1.4
“Acknowledge After Every Byte” Rule
8.5.1.5
Addressing Transfer Formats
8.5.1.6
Control Register Write Cycle
8.5.1.7
Control Register Read Cycle
8.5.2
EEPROM
8.6
Register Maps
8.6.1
Register Bit Explanations
8.6.1.1
Brightness Control
8.6.1.2
Device Control
8.6.1.3
Fault
8.6.1.4
Identification
8.6.1.5
Direct Control
8.6.1.6
Temp MSB
8.6.1.7
Temp LSB
8.6.1.8
EEPROM Control
8.6.2
EEPROM Bit Explanations
8.6.2.1
EEPROM Register Map
8.6.2.2
EEPROM Address 0
8.6.2.3
EEPROM Address 1
8.6.2.4
EEPROM Address 2
8.6.2.5
EEPROM Address 3
8.6.2.6
EEPROM Address 4
8.6.2.7
EEPROM Address 5
8.6.2.8
EEPROM Address 6
8.6.2.9
EEPROM Address 7
9
Application and Implementation
9.1
Application Information
9.2
Typical Applications
9.2.1
Typical Application Using Internal LDO
9.2.1.1
Design Requirements
9.2.1.2
Detailed Design Procedure
9.2.1.2.1
Inductor Selection
9.2.1.2.2
Output Capacitor
9.2.1.2.3
LDO Capacitor
9.2.1.2.4
Output Diode
9.2.1.2.5
Resistors for Setting the LED Current and PWM Frequency
9.2.1.2.6
Filter Component Values
9.2.1.3
Application Curves
9.2.2
Typical Application for Low Input Voltage
9.2.2.1
Design Requirements
9.2.2.2
Detailed Design Procedure
9.2.2.3
Application Curves
10
Power Supply Recommendations
11
Layout
11.1
Layout Guidelines
11.2
Layout Examples
12
Device and Documentation Support
12.1
Trademarks
12.2
Electrostatic Discharge Caution
12.3
Glossary
13
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
YZR|25
MXBG279
Thermal pad, mechanical data (Package|Pins)
Orderable Information
snvs657e_oa
snvs657e_pm
5 Device Default Values
ADDR
EEPROM DEFAULT VALUE
A0h
1010 0001
A1h
0110 0000
A2h
1001 1111
A3h
0011 1111
A4h
0000 1000
A5h
1000 1010
A6h
0110 0100
A7h
0010 1001