2

USING THE EVALUATION BOARD

1) Powering Up the SP6137LED Circuit

The SP6137LED Evaluation Board can be powered from a 12V power supply or from 8 alkaline

cells. Connect with short leads directly to the “VIN” and “GND” posts. Plug the 1W/3W/5W

Luxeon LumiLED between the “VOUT” and “VFB” posts. Refer to section 2 for Jumper (J1)

setup for different LumiLED applications.

2) Using the J1 Jumper for different LumiLED Applications

The SP6137LED Evaluation Board can be used to drive 1W, 3W or 5W LumiLED respectively,

this can be done by using the J1 Jumper. When no hat was used for the J1, it is setup for 1W

application. When the hat is put on 1 & 2 position, it is used for 5W application. When the hat is

put on 2 & 3 position, it is used for 3W application.

3) Selecting the Bias Resistor

at the soft start pin. (The internal 0.8V reference was overwritten by the programmed 0.2V to

reduce the sense voltage and increase the efficiency). The bias resistor is used to set the

operating current of the LumiLED as equation

F

FB

b

I

V

R

=

POWER SUPPLY DATA

For the standard evaluation board, the following chart shows the efficiency data for different

applications.

78

80

82

84

86

88

90

92

94

96

98

100

Single

Two

Three

1W

3W

5W

Fig. 1 Efficiency data of the SP6137LED evaluation board