Datasheet
2
Atmel MSL3086/MSL3088 Datasheet
8-String 60mA LED Drivers with Integrated Boost Controller and Phase Shifted Dimming
Table of Contents
1.0 Packages and Pin Connections ................................................................. 3
2.0 Pin Descriptions .......................................................................................... 4
3.0 Absolute Maximum Ratings ....................................................................... 5
4.0 Electrical Characteristics ........................................................................... 6
5.0 Typical Operating Characteristics ............................................................. 7
6.0 Block Diagram ........................................................................................... 10
7.0 Typical Application Circuit ....................................................................... 11
8.0 Detailed Description ................................................................................. 12
8.1 Differences between the MSL3086 and MSL3088 ........................................................12
8.2 Operating the MSL3086/88 ...........................................................................................12
8.3 Boost Regulator Overview ............................................................................................. 13
8.4 Error Amplier ................................................................................................................ 13
8.5 Gate Driver ....................................................................................................................14
8.6 Soft-Start .......................................................................................................................14
8.7 Boost Fault Monitoring and Protection ..........................................................................14
8.8 LED Current Regulators and PWM Dimming Modes ....................................................14
8.9 Efciency Optimizer (EO) ..............................................................................................14
8.10 Fault Monitoring and Auto-Handling ..............................................................................14
8.11 Internal Supervisory and LDO .......................................................................................15
8.12 Internal Oscillator ........................................................................................................... 15
8.13 Over Temperature Shutdown ......................................................................................... 15
8.14 Power Saving Modes ..................................................................................................... 15
8.15 I
2
C Serial Interface and Driver Control...........................................................................15
9.0 Application Information ............................................................................ 16
9.1 Bypassing VIN and PVIN ...............................................................................................16
9.2 Setting the LED Current ................................................................................................16
9.3 Fault Monitoring and Automatic Fault Handling ............................................................. 16
9.4 Setting the LED Short-Circuit Threshold on the MSL3086 ............................................16
9.5 Boost Regulator ............................................................................................................. 17
9.6 The Efciency Optimizer (EO) .......................................................................................18
9.7 Setting the Boost Regulator Output Voltage .................................................................. 19
9.8 Choosing the Input and output Capacitors ....................................................................19
9.9 Choosing the Inductor ...................................................................................................19
9.10 Setting the External MOSFET Current Limit .................................................................. 20
9.11 Choosing the Switching MOSFET .................................................................................20
9.12 Choosing the Output Rectier .......................................................................................20
9.13 Loop Compensation ......................................................................................................20
10.0 LED Dimming Control ............................................................................... 22
10.1 External I
2
C Control of LED Brightness .........................................................................22
10.2 Phase Shifted LED Dimming Signals ............................................................................22
11.0 Ordering Information ................................................................................ 23