Datasheet Analog Devices ADP1621 — 数据表

Constant-Frequency, Current-Mode
Step-Up DC-to-DC Controller
ADP1621 Data Sheet
FEATURES TYPICAL APPLICATION CIRCUIT APD bias
Portable electronic equipment
Isolated dc-to-dc converter
Step-up/step-down dc-to-dc converter
LED driver for laptop computer and navigation system
LCD backlighting GENERAL DESCRIPTION
The ADP1621 is a fixed-frequency, pulse-width modulation
(PWM), current-mode, step-up converter controller. It drives an
external n-channel MOSFET to convert the input voltage to a
higher output voltage. The ADP1621 can also be used to drive
flyback, SEPIC, and forward converter topologies, either isolated
or nonisolated.
The ADP1621 eliminates the use of a current-sense power
resistor by measuring the voltage drop across the on resistance of
the n-channel MOSFET. This technique, allowed up to a
maximum voltage of 30 V at the switch node, maximizes
efficiency and reduces cost. For switch-node voltages higher than
30 V or for more accurate current limiting, the CS pin can be
connected to a current-sense resistor in the source of the MOSFET.
The slope compensation is implemented by an external resistor, …