MAX8830EWET(2007) View Datasheet(PDF) - Maxim Integrated
Part Name
Description
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MAX8830EWET Datasheet PDF : 15 Pages
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LED Light Management IC in
2.5mm x 2.5mm UCSP
VIN
2.7V TO 5.5V
L1*
10μH
LX
IN
CIN
10μF
GND
CCOMP
RCOMP
PGND
COMP
CHIP POWER
AND
REFERENCE
1MHz
MOVIE ON /OFF
FLASH ON /OFF
SERIAL
INTERFACE
VLOGIC
CVDD
0.1μF
MVON
FLEN
FLASH
MAX TIMER
(0.5/1.0/1.5/2.0s)
SCL
SDA
I2C
PORT
VDD
nFET
pFET
PWM
BOOST
CONVERTER
MAX8830
-
+ VREF
OUT
COUT
10μF
4
4
5
2
5
REGISTERS
AND
LOGIC
5
8
5
200mA
FLASH
FLED
LED
LED1
LED2
LED3
LED4
IOUT
280mA
*L1 = TOKO 1098AS-100M
Figure 1. Block Diagram and Typical Application Circuit
Detailed Description
The MAX8830 light management IC integrates a 280mA
PWM step-up DC-DC converter, a 200mA white LED
camera flash current sink, and four programmable LED
current sinks. An I2C interface controls individual on/off
of all outputs, step-up output voltage setting, movie/
flash current and flash timer-duration settings, and indi-
vidual current sink settings. Figure 1 shows the block
diagram and typical application circuit.
Step-Up Converter (LX, OUT, COMP, PGND)
The MAX8830 includes a fixed-frequency, PWM step-up
converter that supplies power to the LEDs and additional
loads, such as audio amplifiers. The output voltage is
programmable from 3.8V to 5.2V (in 100mV steps)
through the I2C port. If the output voltage is not pro-
grammed, the step-up converter remains off; however, if
any of the current regulators are programmed, the boost
converter p-channel synchronous rectifier is turned on.
The step-up converter switches an internal power
MOSFET and synchronous rectifier at a constant 1MHz
frequency with varying duty cycle up to 75% to maintain
constant output voltage as VIN and load vary. Internal
circuitry prevents any unwanted subharmonic switching
by forcing a minimum 4% duty cycle.
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