IS31BL3228AB Datasheet, PDF (1/11 Pages) Integrated Silicon Solution, Inc – Built-in thermal protection

IS31BL3228A/B
WHITE LED DRIVER
GENERAL DESCRIPTION
The IS31BL3228A (IS31BL3228B) is a low noise,
constant frequency charge pump DC/DC converter
for white LED applications. The IS31BL3228A
(IS31BL3228B) is capable of driving up to four (six)
channels of LEDs at preset 20mA per channel from a
2.8V to 5.5V input. The current sinks may be operated
individually or in parallel for driving higher current
LEDs. Only one 1μF small capacitor (at C+ thru C-)
and two small 2.2μF capacitors (at V_CC and V_OUT) are
needed, it makes this part ideally suited for small,
battery-powered applications.
The serial digital input is used to enable, disable, and
set current for each LED with 14 settings down to
1.8mA. Each output of the
IS31BL3228A/IS31BL3228B is equipped with built-in
soft-start circuitry prevents excessive inrush current
during start-up. A low-current shutdown feature
disconnects the load from the input and reduces
quiescent current to less than 3μA.
The IS31BL3228A and IS31BL3228B are available in
a Pb-free, space-saving 2mm × 2mm UTQFN-12
package.
TYPICAL APPLICATION CIRCUIT
January 2014
FEATURES
 V_CC range: 2.8V to 5.5V
 Fully programmable current with single wire
 14 current levels
 Drives up to four (IS31BL3228A)/six
(IS31BL3228B) channels of LEDs
 No inductors, low noise operation
 Built-in thermal protection
 Automatic soft start
 Low shutdown current: I_SD <3μA
 UTQFN-12 (2mm × 2mm ) package
APPLICATIONS
 Cell phone, smart phone, PDA
 MP3, MP4, PMP
 White LED backlighting
Figure 1 Typical Application Circuit (IS31BL3228A)
Note: C_OUT can’t be less than 2.2μF, and when less than six channels are used, keep the unused pin to GND or floating. But channel D0 (Pin 1)
has to be used.
Integrated Silicon Solution, Inc. – www.issi.com
1
Rev. B, 12/31/2013