IS31BL3232 FLASH LED DRIVER
Integrated Silicon Solution, Inc. – www.issi.com 1
Rev. A, 07/23/2013
DESCRIPTION
The IS31BL3232 is a charge pump constant
current-regulated LED driver ideal for powering high
brightness LEDs for camera flash and torch
applications. The charge pump can be set to regulate
two current levels for Flash or Torch modes. The
IS31BL3232 automatically switches between linear
and boost modes; the charge pump will start up
automatically to offer a higher output voltage when V
FB
is lower than the setting value. In the Flash Mode the
output will shut down automatically after 1s to save
energy.
IS31BL3232 provides low cost, space saving solution
for driving LED. It also integrates thermal and short
circuit protection function.
FEATURES
Operates from 2.7V to 5.5V
Up to 90% efficiency in Torch Mode
Output current up to 1.2A(1s) in Flash Mode
Adjustable output current in Flash Mode
Time out function with 1s for Flash Mode
Minimum external components, no external
inductor required
Automatic boost mode
Less than 1µA shutdown current
Low ripple and EMI
Over voltage protection on output
ESD HBM 8kV
Short and over temperature protections
Available in DFN-10 (3mm × 3mm) package
QUICK START
Figure 1: Photo of IS31BL3232 Evaluation Board
RECOMMENDED EQUIPMENT
3.0V~5.0V, 2A power supply
ABSOLUTE MAXIMUM RATINGS
≤ 5.5V power supply
Caution: Do not exceed the conditions listed above, otherwise
the board will be damaged.
PROCEDURE
The IS31BL3232 evaluation board is fully assembled
and tested. Follow the steps listed below to verify
board operation.
Caution: Do not turn on the power supply until all connections
are completed.
1) Connect the ground terminal of the power supply
to the GND and the positive terminal to the VCC.
Or connect the DC power to the connector (DC
IN).
2) Turn on the power supply and pay attention to the
supply current. If the current exceeds 1.5A,
please check for circuit fault.
EVALUATION BOARD OPERATION
The evaluation board is controlled by LPC922 (8051
core).
IS31BL3232 evaluation board demonstrates the Flash
and Torch modes by switching between modes when
the corresponding buttons are pressed.
1)
Torch Mode (Default):
The
“
Bright+
”
and
“
Bright-
”
buttons are used to control the WLED
brightness. The LEDs on the left graphically show
the brightness level. The default power on level is
D1, the lowest level. The
“
Torc h
”
button is used to
Enable/Disable this mode.
2)
Flash Mode:
Once pressed the white LEDs will
flash ON for one second.
SOFTWARE SUPPORT
Please refer to the integrated program.
Jumper JP1 is closed (default). Remove the jumper
on JP1 (on board LPC922 MCU disabled) if you want
to use an external MCU control. Connect the external
MCU I/O signals to the TP3 connector to directly
control the IC’s EN and FLASH input pins.
Please refer to the datasheet to get more information about
IS31BL3232.
