IS31BL3506A Datasheet, PDF (1/13 Pages) Integrated Silicon Solution, Inc – 1.0MHZ BOOST CONVERTER WITH 35V INTERNAL MOSFET SWITCH

IS31BL3506A
1.0MHZ BOOST CONVERTER WITH 35V INTERNAL MOSFET SWITCH
July 2012
GENERAL DESCRIPTION
IS31BL3506A is a boost converter featuring an
integrated MOSFET switch designed for driving series
strings of LED or other device. Input operating voltage
range is 2.7V~5.5V. The device regulates the LED load
current is set using an external, low value sensing
resistor. The device adjusts the PWM duty cycle of the
switch to maintain the voltage at the FB pin at a value
of 0.3V. The IS31BL3506A operates at a constant
switching frequency of 1.0MHz to allow for small
component size. IS31BL3506A features an over
voltage shutdown pin which prevents the output
voltage from exceeding 35V (typ.) in the case of an
open circuit condition. The device is offered in a tiny
TSOT-23-6 and DFN-8 (2mm×2mm) package and a
temperature rating from -40°C ~ +85°C.
FEATURES
 Supply voltage: 2.7V~5.5V
 Built-in soft start
 Drive series strings of
-9 LEDs (DFN-8)
-8 LEDs (TSOT-23-6)
 PWM or DC voltage dimming
 Frequency of PWM is 500Hz ~ 500kHz
 1.0MHz high speed switching frequency
 300mV feedback voltage
 Integrated high power MOSFET
 Over voltage protection
 -40°C ~ +85°C working temperature range
 TSOT-23-6 and DFN-8 (2mm×2mm) package
APPLICATIONS
 Small LCD Backlights
 Notebook PC
 GPS
TYPICAL APPLICATION CIRCUIT
Figure 1 Constant current white LED driver using PWM at the EN pin to control intensity
Note 1: COUT must be rated for 50V. Smaller values of output capacitance will cause the LED current ripple to increase.
Note 2: The resistor REST should be placed as close as possible to the FB pin to prevent the EMI.
Note 3: Because of the different packages, VOVP is not the same (Page 6). 9 LEDs can be driven by DFN-8 package and 8 LEDs can be driven
by TSOT-23-6 package most.
Note 4: The high level of PWM signal for EN pin should last at least 200ns when power on, or the IC won’t start up.
Integrated Silicon Solution, Inc. – www.issi.com
1
Rev. B, 07/02/2012