IS31BL3231-DLS2-TR ISSI, IS31BL3231-DLS2-TR Datasheet - Page 9

• Manufacturer Part Number: IS31BL3231-DLS2-TR
• Description: LED Lighting Drivers Camera Flsh LED Drvr
• Manufacturer: ISSI

Specifications of IS31BL3231-DLS2-TR

• Output Current: 750 mA
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: DFN-10
• Factory Pack Quantity: 2500

IS31BL3231
APPLICATION INFORMATION
GENERAL DESCRIPTION
The IS31BL3231 is a current-regulated charge pump
and ideal for powering high brightness LEDs for
camera flash and torch applications.
CHARGE PUMP
The charge pump converter boosts input supply
voltage (V
drive LED.
The charge pump converter only requires three
external components: supply decoupling capacitor,
output bypass capacitor and flying capacitor.
Choose low ESR capacitors to ensure the best
operating performance and place the capacitors as
close as possible to the IS31BL3231.
The charge pump will start up automatically to offer a
higher output voltage when V
setting value.
CURRENT SETTING
The LED current is set by the external resister, R
following the Equation (1) below.
V
IS31BL3231 operates in the Flash Mode. V
the Table 1 when IS31BL3231 operates in the Torch
Mode.
OPERATING MODE
FLASH MODE
By pulling the FLASH pin to high, IS31BL3231
operates in the Flash Mode. V
For example, in Figure 1,
R
So,
The maximum V
actual current will be large difference from then
calculated current.
Integrated Silicon Solution, Inc. – www.issi.com
Rev. B, 11/28/2012
FB
FB
is calculated by the Equation (2) when
= 0.22Ω, R
V
I
FB
LED
V
FB

CC



. 1
158
) up to a higher output voltage (V

25
. 1
I
SET
LED
V
25
mV
FB
/
V
= 88.7kΩ,
shouldn’t be over 550mV or the
88

/
/
V
. 0
7 .
R
FB
22
SET
k

/

R




FB
FB

11
11
FB
718
is lower than the
2 .
is set by the R
2 .
k
k
mA


(1)

158
FB
mV
(2)
OUT
is set in
SET
) to
FB
.
,
TORCH MODE
By pulling the FLASH pin to low, IS31BL3231 operates
in the Torch Mode. The V
Count Control (PCC wire) serial interface. The
interface records rising edges of the EN pin and
decodes them into 8 different states. The 8 voltage
level settings available are indicated in Table 1.
Table 1 V
TIMING CONTROL
The EN pin should be configured as the Figure 11. t
is the latch time. High level should be at last t
active the pulse signal. t
pin is pulled low at last t
THERMAL PROTECTION
The IS31BL3231 has a thermal protection circuit that
will shut down the chip if the die temperature rises
above the thermal limit until the temperature falls
down.
Pulse
≥ 8
1
2
3
4
5
6
7
FB
V
100mV
120mV
140mV
170mV
FB
Control
50mV
60mV
70mV
85mV
(Typ.)
Figure 11 EN pin timing
OFF
OFF
FB
R
the IC will be shutdown.
is controlled by Pulse
is the shutdown time. EN
FB
227mA
273mA
318mA
386mA
455mA
545mA
636mA
773mA
= 0.22Ω
I
LED
(Typ.)
R
100mA
120mA
140mA
170mA
LAT
FB
50mA
60mA
70mA
85mA
= 1Ω
to
LAT
9