Datasheet
Table Of Contents
- Features
- Typical Applications
- 1. Introduction
- 2. Ordering Information
- 3. Application Circuit
- 4. Absolute Maximum Ratings
- 5. Electrical Characteristics
- 6. Block Diagram
- 7. Pinout and Pin Description
- 8. Typical Application Circuit
- 9. Detailed Description
- 10. Fault Conditions
- 11. Applications Information
- 12. Control Registers
- 13. Detailed Register Descriptions
- 13.1 RAM (0x00 through 0x1F)
- 13.2 Main String Reference Voltage register (MREF, 0x20)
- 13.3 Color-Adjust String Reference Voltage register (CAREF, 0x21)
- 13.4 Fault Disable register (FAULT, 0x22)
- 13.5 Fault Status register (FAULTSTAT, 0x23), Read Only
- 13.6 Sleep register (SLEEP, 0x24)
- 13.7 Main String Duty Cycle register, High Byte (MDUTYHIGH, 0x34)
- 13.8 Main String Duty Cycle register, Low Byte (MDUTYLOW, 0x35)
- 13.9 Color Adjust String Duty Cycle register, High Byte (CADUTYHIGH, 0x36)
- 13.10 Color Adjust String Duty Cycle register, Low Byte (CADUTYLOW, 0x37)
- 13.11 Efficiency Optimizer Control Register (EOCTRL, 0x40)
- 13.12 Registers 0x60 and 0x61, EEPROM Access
- 14. I²C Serial Interface
- 15. Packaging Information
- 16. Datasheet Revision History
- Table of Contents

30
MSL2023/2024 [DATASHEET]
42063A–LED–02/2013
Table 13-10. Color Adjust String Duty Cycle Low register (CADUTYLOW, 0x37), default highlighted.
13.11 Efficiency Optimizer Control Register (EOCTRL, 0x40)
Configures three functions associated with the Adaptive SourcePower™ Efficiency Optimizer (EO). It is recommended
that all EO controls be configured while SLEEP (bit D0 in the Configuration register 0x24) is 1 to avoid perturbations of
the string power supply. The MSL2023/24 always perform a power supply voltage calibration when power is applied, EN
is taken high, or SLEEP is reset to 0.
DThresh sets the voltage feedback threshold for D, the main string MOSFET drain connection. D Threshold =
(DThresh*150mV) + 250mV. This is how the device monitors V
LED
to control the magnitude of the EO current. The
default value for DThresh is 1V.
Table 13-11. Efficiency Optimizer Control Register (FBOCTRL, 0x40), defaults highlighted.
13.12 Registers 0x60 and 0x61, EEPROM Access
These registers control access to the EEPROM. See “EEPROM and Power-Up Defaults” and “EEPROM Address and
Control/Status Registers” on page 25 for information.
14. I²C Serial Interface
The MSL2023/24 operate as slaves that send and receive data through an I²C/SMBus compatible 2-wire serial interface.
The interface is not needed for operation, but is provided to allow control and monitoring of device functions. These
functions include changing the string current reference feedback voltages, reading and adjusting the fault response
behavior and status, putting the device to sleep without losing the register settings, and programming the EEPROM. The
I²C/SMBus compatible interface is suitable for 100kHz, 400kHz and 1MHz communication. The interface uses data I/O
SDA and clock input SCL to achieve bidirectional communication between master and slaves. Fault output FLTB
optionally alerts the host system to faults detected by the MSL2023/24 (Figure 14-1 on page 31 and “Fault Conditions” on
page 18). During over temperature shutdown the serial interface is disabled.
The master, typically a microcontroller, initiates all data transfers, and generates the clock that synchronizes the
transfers. SDA operates as both an input and an open-drain output. SCL operates only as an input, and does not perform
clock-stretching. Pull-up resistors are required on SDA, SCL and FLTB.
Register name
Address /
Default
Register data
D7 D6 D5 D4 D3 D2 D1 D0
CADUTYLOW 0x37 – – – – CADUTYLOW[3:0]
DEFAULTS = 0x0F 0 0 0 0 1 1 1 1
Register name Address
Register data
D7 D6 D5 D4 D3 D2 D1 D0
FBOCTRL 0x40 Reserved[3:0] DTHRESH[3:0]
DEFAULT = 0xE5 111001 0 1
D Threshold = (0 * 150mV) + 250mV = 0.25V 111000 0 0
D Threshold = (5 * 150mV) + 250mV = 1V 111001 0 1
D Threshold = (15 * 150mV) + 250mV = 2.5V 111011 1 1