LP5522TMEV National Semiconductor, LP5522TMEV Datasheet - Page 5

• Manufacturer Part Number: LP5522TMEV
• Description: BOARD EVAL LP5522 LED DRIVER
• Manufacturer: National Semiconductor
• Series: PowerWise®r

Specifications of LP5522TMEV

• Current - Output / Channel: 20mA
• Outputs And Type: 1, Non-Isolated
• Features: USB Interface
• Voltage - Input: 2.7 ~ 5.5V
• Utilized Ic / Part: LP5522
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Output: -

Getting Started
The following instructions show how to use the LP5522 eval-
uation kit in default conditions with the USB interface board.
Please use ESD protection to prevent any unwanted damag-
ing ESD events
1.
2.
3.
4.
5.
You should disconnect the USB cable from the computer al-
ways when plugging in or removing the evaluation board from
the interface board and also when changing the supply
jumper settings. Otherwise the USB board may stop respond-
ing.
If the USB board is not responding or the software hangs up,
press the reset button on the USB board, or disconnect the
USB cable for 5 seconds.
Check the onboard jumpers. VDD should be connected
to VDD_USB and jumper J19 should be on. Removing
jumper J19 disconnects LED from GND. ISET can be
connected either to VDD or R_ISET.
Plug the evaluation board to the USB board. Connect the
USB cable to the USB Interface board and to the USB
port of your PC. When you plug in the USB board for the
first time, your operating system prompts you about “New
hardware found” and installs the USB driver. With Win95
and Win98 operating systems you have to accept the
installation and click “Next” several times as the
installation proceeds.
Copy the evaluation software and the support files to your
PC’s hard disk. Start the software by double-clicking its
icon. If USB Interface Boards firmware update is required
the software prompts you to allow automatic update.
Turn on the LED by bushing the manual button. If system
is correctly installed the onboard LED should be light.
The Evaluation Kit is now ready to use and the chip can
be controlled through the PC software.
5
If the evaluation software notices that the firmware on the
USB board needs to be updated, the software can propose
automatic firmware updating. The new firmware will be in-
cluded in the evaluation kit software.
PROGRAMMING A SEQUENCE TO THE CHIP
To program a blinking sequence to the chip one to three on-
and off sequences must be selected with the slide bars. On
time can vary between 1 ms to 255 ms with 1 ms steps and
off time can vary between 10 ms to 2550 ms with 10 ms step.
Sequences must be selected in numerical order e.g. you must
first select on- and off time 1 (sequence 1) in order to be able
to use on- and off time 2 (sequence 2). Also both on- and off
times must be selected for each used sequences. The pre-
view window shows the currently selected sequences. To
program this sequence to the chip push the Train button. Dur-
ing the programming the LED will blink as selected. After
programming the Trained window should indicate Yes and the
Run and Run once buttons should be available. Also Manual
button should be unavailable. Figure 5 shows the evaluation
software with two sequences programmed to the chip.
To run the trained sequence push the Run or Run once but-
ton. Pushing the Run once button runs the programmed
sequence once and then puts the chip back to standby mode.
Pushing Run button puts the chip to continuous run mode. To
put the chip back to standby mode push the Run button again.
To reset the chip and to remove the trained sequence from
chip push Reset button. After reset the chip is on its initial
state and the LED follows the Manual button.
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