MAX8607 Maxim Integrated Products, MAX8607 Datasheet - Page 6

• Manufacturer Part Number: MAX8607
• Description: 1MHz PWM Boost Converter
• Manufacturer: Maxim Integrated Products

The MAX8607 includes a fixed-frequency, PWM boost
converter that supplies the LED current. The output
voltage is adaptively controlled to provide adequate
headroom with varying LED forward voltage. The boost
converter switches an internal power MOSFET and syn-
chronous rectifier at a constant 1MHz frequency with
varying duty cycle up to 75% to maintain constant LED
current over the 2.7V to 5.5V input range. Internal spe-
cial circuits prevent any unwanted subharmonic switch-
ing in the critical buck/boost region.
1MHz PWM Boost Converter for 1.5A
White LED Camera Flash
Figure 1. Functional Diagram
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COMP
PGND
FLSH
MOV
GND
EN1
EN2
LX
Detailed Description
CLOCK
1MHz
Boost Converter
MAX8607
SHUTDOWN AND
MODE CONTROL
BOOST CONTROL
FORCED-PWM
A low-dropout (LDO) linear current regulator from LED
to LGND sinks current from the external LED’s cathode
terminal. The LED current is regulated to a user-pro-
grammable level. In movie mode, the current into LED
is regulated to 1200 times the current set by the MOV
resistor (R
regulated to 5000 times the current set by the FLSH
resistor (R
regulated to 80mA.
1.25V
REF
REGULATOR
FLSH
MOV
LDO
). In flash mode, the current into LED is
). In disco mode, the current into LED is
FEEDBACK
SELECT
LDO Current Regulator (LED)
LGND
OUT
OUTS
LED