LX1995

Microsemi

Integrated Products

11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570

Page 6

Copyright

© 2004

Rev. 1.0, 2004-08-13

The LX1995 Evaluation Board has 9 test lead

attachment point for applying power and dimming

inputs or for monitoring voltages.

Function

Board Label

Connection

Input Power

VIN

Power supply (3.55V+/- 1.95V).

Power Ground

GND

Common power supply ground.

Enable

/SHDN

Connect to GND to disable LX1995. A <1KHz logic PWM signal

can also be applied.

DC dimming

DC_ADJ

Apply a 0 to 3V DC dimming input

PWM dimming

PWM_ADJ

Apply a >5KHz 3.3V logic PWM signal.

Output Voltage

VOUT

Test point to monitor voltage across all LEDs.

Signal Ground

GND#

Multiple common grounds for probes. etc

Table 3 – Connection Points

Hints: For best results, use only one of the three possible LED dimming methods at a time. LED current can be monitored

by measuring the voltage from LED4 cathode to GND and dividing by 15 (the value of R4).

NOTE: Jumper JU1 must be connected for the LX1995 to function. This jumper can be replaced with a wire loop so the

inductor current waveform can be observed using a current probe.