Diodes AP3433 - Manual

Preliminary Datasheet
3A, 2MHz High Performance Synchronous Buck Converter AP3433
Jul. 2012 Rev. 1. 1 BCD Semiconductor Manufacturing Limited
1
General Description
The AP3433 is a current mode, PWM synchronous
buck (step-down) DC-DC converter, capable of
driving a
3A load with high efficiency, excellent line
and load regulation.
The device integrates two N-channel power
MOSFETs with low on-resistance. Current mode
control provides fast transient response and
cycle-by-cycle current limit.
The switching frequency of AP3433 can be
programmable from 300kHz to 2MHz, which allows
small-sized components, such as capacitors and
inductors. A standard series of inductors from several
different manufacturers are available. This feature
greatly simplifies the design of switch-mode power
supplies.
Under voltage lockout is internally set at 2.6V, but
can be increased by programming the threshold with
a resistor network on the enable pin. The output
voltage startup ramp is controlled by the soft-start pin.
An open drain power good signal indicates the output
is within 93% to 107% of its nominal voltage.
The AP3433 is available in QFN-3×3-16 package.
Features
• Input Voltage Range: 2.95V to 5.5V
• 0.827V Reference Voltage with ±3% Precision
• Two 45m
Ω(typical) MOSFETs for High
Efficiency at 3A Load
• High Efficiency: up to 94%
• Output Current: 3A
• Programmable Frequency:300kHz to 2MHz
• Current Mode Control
• Synchronizes to External Clock
• Adjustable Soft-start
• Soft Start-up into Pre-biased Output
• UV and OV Power Good Output
• Built-in Over Current Protection
• Built-in Thermal Shutdown Function
• Programmable UVLO Function
• Built-in Over Voltage Protection
• Thermally Enhanced 3mm×3mm 16-pin QFN
Applications
• Low-voltage, High-density Power Systems
• Point of Load Regulation for Consumer
Applications such as Set Top Boxes, LCD
Displays, CPE Equipment
Figure 1. Package Type of AP3433
QFN-3Ч3-16