LP5526TLEV National Semiconductor, LP5526TLEV Datasheet - Page 2

• Manufacturer Part Number: LP5526TLEV
• Description: BOARD EVAL LP5526 LMU LED DRIVER
• Manufacturer: National Semiconductor
• Series: PowerWise®r

Specifications of LP5526TLEV

• Current - Output / Channel: 150mA
• Outputs And Type: 2 (25mA), 1 (150mA)
• Voltage - Output: 20 V
• Features: Camera Flash, Dimmable, RGB Controller
• Voltage - Input: 3 ~ 5.5V
• Utilized Ic / Part: LP5526
• Lead Free Status / RoHS Status: Not applicable / Not applicable

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Evaluation Software
LP5526 evaluation software and some support files are sup-
plied on the delivery CD together with all available documen-
tation regarding the circuit. You can copy the software and the
files to your PC’s hard disk. The program and the support files
must be in the same folder. The software is started by double-
clicking its icon. The software does not require any installa-
tion.
The evaluation software is organized in tabs according to the
main functions of the chip. On the left side of the tabs is shown
COMMON TAB
Only one bit of the Enables register is controlled in the Com-
mon Tab. The NSTBY bit controls the chip on/off state.
The Common Tab contains also evaluation board control
functions. Automatic writing (Update registers immediately) is
enabled by default. It means that a write operation is done
after every mouse click. If you want to change several settings
in one or more tabs and write the register(s) after making all
the changes, you can disable automatic writing. Then after
the changes you have to initiate the register write by clicking
the right mouse key with the cursor in the Register Map area.
From the pop-up menu you can choose to write all registers
or just a selected register. The same pop-up lets you write
default values to one or all registers and read one or all reg-
isters.
After clicking the “Hardware reset” button, all register values
will be reset to default value, and a pop-up window appears
where user can accept reading all the registers (this is rec-
ommended). Another way to reset the chip is to disconnect
the USB cable (or external power if it is used) for a few sec-
onds, plug it in again and read all registers to see that they
have the default values after the power-on-reset. USB setup
button will restore default setting for USB interface board.
Figure 2. LP5526 Evaluation Software User Interface
2
the whole register map of LP5526. Below the tabs are shown
the registers, which are affected by the selected tab. Both
register displays reflect immediately the changes you make
by clicking the selection boxes or sliders in the tabs. The con-
tents of the tabs should be mostly self-explanatory. Some
example register settings are included in the delivery CD and
they can be loaded from the File/Open menu. You can simi-
larly save your own settings.
USB board can measure voltages from the evaluation board.
On the LP5526 board the circuit V
put voltage V
abled, when the Polling interval in the Common tab is set.
Measurement results are shown on top of the window.
The software can demonstrate external PWM brightness con-
trol using the GPIO[0]/PWM input. PWM signal is generated
by the software. External PWM can only reduce the bright-
ness set by internal controls. All the LEDs have enable bits
(en_ext_X_pwm, en_main_pwm, en_sub_pwm) for allowing
external PWM control. These bits are controlled in corre-
sponding LED control Tabs (Color LEDs and Backlight). Ex-
ternal PWM control has no effect to the outputs that do not
have enable bit set. You must also set ‘en_pwm_pin’ bit in
GPIO tab to set GPIO[0]/PWM pin act as an external PWM
input pin.
Note that when Flash button (in Color LEDs Tab) is used and
released, it resets the PWM pulse ratio. In the Common Tab
the External PWM slider controls the duty cycle of the GPIO
[0]/PWM input pin. Measurement polling disturbs the External
PWM control and it should be turned off when External PWM
is used.
BOOST
are measured. Measurements are en-
DDIO
and the converter out-
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