LX1990-03 EVAL KIT MICROSEMI, LX1990-03 EVAL KIT Datasheet - Page 4

• Manufacturer Part Number: LX1990-03 EVAL KIT
• Manufacturer: MICROSEMI

Specifications of LX1990-03 EVAL KIT

• Lead Free Status / RoHS Status: Supplier Unconfirmed

LX1990 E
The PWM input TP9 engaged by JP8 allows an
external PWM signal to control the output
current
accomplished by switching the I
and off.
frequency is about 20Khz, at frequencies greater
than this internal delays will add errors to the
expected output duty cycle. Q1, R2 and R4
provide an open collector drive for the I
resistor so a standard pulse generator can be
used for evaluation purposes. For greater detail
see the LX1990 datasheet.
Test Points TP7 and TP8 allow you to monitor
the voltage drop across the LX1990 for the I
and I
range from as low as 100mV to 10V when the
Copyright © 2002
Rev. 0.1a, 4/9/02
Jumper
TP2,4,6,10
Point
JB1
JB2
JB3
JB4
JB5
JB6
JB7
JB8
Test
TP1
TP3
TP5
TP7
TP8
TP9
OUTB
by
outputs to ground. This voltage can
The practical limit to this switching
OFF position grounds Enable input; EXT/ON connects enable to TP5 with 100K pull-up
IN position bypasses (shorts) LED1; OUT leaves LED1 connected to output LED string
IN position bypasses (shorts) LED2; OUT leaves LED2 connected to output LED string
IN position bypasses (shorts) LED3; OUT leaves LED3 connected to output LED string
IN position bypasses (shorts) LED4; OUT leaves LED4 connected to output LED string
IN position bypasses (shorts) LED5; OUT leaves LED5 connected to output LED string
IN position bypasses (shorts) LED6; OUT leaves LED6 connected to output LED string
ON position connects PWM (TP9) to RSET resistors; OFF leaves RSET connected to
ground
VALUATION
duty
VLOAD Input, power supply to LED’s
Common Ground Reference
VDD Input to LX1990
ENABLE input can be connected to external enable signal; high or floating is on, low is
off
I
I
PWM Input can be connected to external pulse generator for duty cycle dimming
OUTA
OUTB
(LX1990 pin 6)
(LX1990 pin 4)
cycle
B
dimming.
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: [phone]
OARD
SET
Table 3 – Test Point Descriptions
Table 2 – Jumper Explanation
current on
This
OUTA
SET
Integrated Products
is
Microsemi
Description
Function
outputs are off depending on the VLOAD supply
voltage.
The various jumper positions are summarized in
table 2 and test points in table 3. The factory
installed active and passive components list can
be found in table 4. Following the two tables
you will find the PCB silkscreen figure 1 and the
circuit schematic in figure 2. All necessary PCB
traces and components are on the topside of the
board.
silkscreen on the bottom side that when
populated is used for a special version of the
evaluation board that is used internally by
Microsemi
purposes.
However there are PCB traces and
for
training
and
U
demonstration
SER
G
UIDE
Page 4