MP1528DK MPS [Monolithic Power Systems], MP1528DK Datasheet - Page 5

• Manufacturer Part Number: MP1528DK
• Description: 9 Lamp, 36V Precision White LED Driver
• Manufacturer: MPS [Monolithic Power Systems]

PIN FUNCTIONS
MP1528 Rev. 1.7
2/21/2006
QFN6 MSOP8
1
2
3
4
5
6
Pin #
1, 8
2
3
4
5
6
7
TM
Name Description
GND
BIAS
BRT
SW
EN
NC
FB
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
Feedback Input. The MP1528 regulates the voltage across the current sense resistor
between FB and GND. Connect a current sense resistor from the bottom of the LED
string to GND and connect the bottom of the LED string to FB. The regulation
threshold is set at 0.4V for V
Ground.
Power Switch Output. SW is the drain of the internal MOSFET switch. Connect the
power inductor and output rectifier to SW, which can swing between GND and 42V.
Internal Power Input. BIAS powers the internal circuitry and measures the output
voltage for open circuit protection. Connect BIAS to the output at the top of the LED
string. If open circuit protection is not required, BIAS may be connected to the input
source to reduce power consumption of the MP1528.
Regulator On/Off Control Input. A high voltage applied to EN turns on the converter;
a low voltage turns it off. When not used, connect EN to the input source for
automatic startup. If EN is driven over 6V, place a 100kΩ resistor in series with EN.
Never leave EN floating.
Analog or PWM Input for Controlling LED Brightness. When used in analog mode,
apply a DC voltage of 0.27V to 1.2V. This input voltage is attenuated by 1/3 to set
the voltage across the sense resistor at FB. Maximum brightness (20mA) occurs with
an application of 1.2V. To control the brightness in PWM mode, apply a PWM signal
with a minimum voltage less than 0.18V and a maximum voltage greater than 1.2V
(when a voltage less than 0.18V is applied to this pin, the output switch is turned off).
The regulator operates at maximum brightness when more than 1.2V is applied. The
frequency of the PWM signal must be between 100Hz to 400Hz.
No Connect
© 2006 MPS. All Rights Reserved.
www.MonolithicPower.com
MP1528 – 9 LAMP, 36V PRECISION WHITE LED DRIVER
BRT
≥ 1.2V.
5