LM3528TMEV National Semiconductor, LM3528TMEV Datasheet - Page 6

• Manufacturer Part Number: LM3528TMEV
• Description: BOARD EVAL FOR LM3528 12MCRSMD
• Manufacturer: National Semiconductor

Specifications of LM3528TMEV

• Current - Output / Channel: 20mA
• Outputs And Type: 2, Non-Isolated
• Voltage - Output: 21V
• Features: Dimmable, I²C Interface
• Voltage - Input: 2.5 ~ 5.5V
• Utilized Ic / Part: LM3528
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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LM3528–USB Interface Board and
I
In order to fully evaluate the LM3528, the use of an “I
patible” interface must be used for any functionality to occur.
The detailed description regarding the interface control, the
LM3528 registers, and OLED mode is described in the
LM3528 datasheet.
National has created an I
6) and a USB Interface Board that can help exercise the part
in a simple way. The LM3528 evaluation board has the means
to “plug into” the USB Interface Board. The USB Interface
Board provides all of the control signals for the simple inter-
face and can provide power to the part as well. A jumper on
the LM3528 evaluation board labeled VIN/VUSB allows the
user to connect either an external power supply to the VIN
header on the LM3528 evaluation board, or draw power from
the USB board. Removal of the jumper disables the connec-
tion of the USB power supply. Once removed, an external
supply is required. If the jumper is installed the USB board
supplies power to the LM3528 Evaluation board. No adjust-
ments to the USB board are needed. A standard USB cable
must be connected to the board from a PC in order to com-
municate with the LM3528 Evaluation Kit.
For proper operation, the USB Interface board must be
plugged into the PC before the LM3528.exe interface pro-
gram is opened. Once connected, and the program is exe-
cuted, a basic interface window will open. At the top of the
interface, the user can read or write to any of the data regis-
ters on the LM3528 using the two pull down menus for the
slave I.D. and the desired data address. The data field to the
right of the Address pull-down menu accepts hex data while
the read and write buttons directly below the Address pull-
down menu execute the Read or Write command.
Just below the Read and Write buttons are five enable but-
tons. Two dedicated enable bits (ENM and ENS) will enable
the two LED strings (MAIN and SUB). A dedicated bit (UNI)
enables the Unison Mode of the two LED banks, and another
bit (OLED) puts the part in OLED mode. The Enable All button
simultaneously enables both ENS and ENM.
Below the enable buttons are two sliding bars and data fields
that allow all 128 levels of brightness for the MAIN and SUB
2
C Compatible Interface Program
2
C-compatible program (see Figure
2
C Com-
6
banks. Just below the two brightness level slider bars are six
convenient action buttons: three set buttons and three reset
buttons.
SetM sets the MAIN brightness level to full-scale and enables
the MAIN bank.
ResetM resets the MAIN brightness level to zero and disables
the MAIN bank.
SetS sets the SUB brightness level to full-scale and enables
the SUB bank.
ResetS resets the SUB brightness level to zero and disables
the SUB bank.
Set sets the MAIN and the SUB brightness levels to full scale
and enables the MAIN and SUB banks.
Reset resets the MAIN and SUB brightness levels to zero and
disables the MAIN and SUB banks.
To the right of the 2 brightness level slider bars is a pull-down
menu which controls the ramp rate of the brightness level. To
the left of the 2 brightness level slider bars are convenient
controls for the GPIO1 pin and the HWEN/PGEN/GPIO pin.
The HWEN/PGEN/GPIO pin has three functions: an active
high hardware enable (HWEN), a pattern generator output
(PGEN), and a general purpose I/O (GPIO). At the bottom of
the user interface are button controls for creating the output
pattern when HWEN/PGEN/GPIO is in PGEN mode. (see the
LM3528 datasheet for a detailed explanation of the pattern
generator). The output pattern is determined by the concate-
nation of four 8-bit data registers: x90, x91, x92 and x93. Each
bit for each of these data registers can be set in the user in-
terface (Byte 0 – Byte 3). The hex value of the data register
is displayed to the right of the data bits in a data field. To the
right of the register data fields are convenient buttons to set
all the bits to 1’s or reset all the bits to 0’s.
Once the user has selected the desired pattern, the user loads
the pattern into the LM3528 by clicking the “Load” button.
Once the output pattern has been loaded, the users can then
select the bit period and duty cycle of the pattern using the
pull-down menus. Finally, the output pattern is executed by
clicking the “Run” button.
Note: If the part is enabled to any brightness level and the
program is closed, the LM3528 part will remain in the last
programmed state.