LM3559EVAL/NOPB

EVAL BOARD FOR LM3559

1 Introduction

The LM3559/LM3560 Evaluation Board is designed to fully evaluate the LM3559 and LM3560 Synchronous Boost Converter with dual 900mA High Side Flash LED Drivers (LM3559) or dual 1000mA High Side Flash Drivers (LM3560) and I2C-Compatible Interface. Detailed descriptions for either parts can be found in their device-specific data sheets.

The board comes equipped with two Lumiled Flash LEDs (LXCL-EYW4). An additional LED (LED3) is a red LED which operates as the message indicator. The on-board flash button demonstrates the hardware flash feature of the LM3559/LM3560 and, when pushed, the Flash LEDs turn on at their programmed Flash current. There are two 4.7kΩ pull-up resistors on board for the I2C clock and data lines and a 4.7kΩ pull-up (R_HWEN) that pulls the active high hardware enable pin (HWEN) high. Each Input and/or output from the LM3559 has its own separate header pin to serve as a test-point.

2 Evaluation Board Bill of Materials

3 Operation

To operate the LM3559/LM3560 evaluation board, connect a jumper from the VI/O pin to the IN pin (3-pin header at bottom left of board). This connects the logic level pull-ups to VIN. Next, connect a jumper across the IN VL header. This will short the IN pin and the input terminal of the inductor. This jumper is designed to remove the input bypass capacitor from the input of the inductor to measure the inductor current ripple. With these jumpers in place, connect a 2.5V to 5V supply between the VL banana jack and GND.

Control of the LM3559/LM3560 can be done via two ways. At the top left corner of the board there are two 2-pin headers (SCL/GND and SDA/GND). To control the LM3559/LM3560 using a data generator or an external I2C device connect the I2C lines directly to the SCL and SDA pins of the respective header. Alternatively you can use the Texas Instruments USB board to supply the I2C data (see Section 3.1).