AP3436 Datasheet, PDF (1/15 Pages) BCD Semiconductor Manufacturing Limited – 3A, 1.25MHz High Performance Synchronous Buck Converter

Data Sheet
3A, 1.25MHz High Performance Synchronous Buck Converter AP3436/A
General Description
The AP3436/A is a step-down DC-DC converter
with integrated power stage capable of driving up to
3A continuous output current. It integrates 2
N-channel power MOSFETs with low on-resistance.
Current mode control provides fast transient
response and cycle-by-cycle current limit.
For AP3436, the regulator adopts current-mode in
forced pulse-width modulation (PWM) mode with
1.25MHz switching frequency internally, which
allows small-sized components, such as capacitors
and inductors. This feature greatly simplifies the
design of switch-mode power supplies. Under PWM
mode, the device remains at the fixed PWM
operation (typical at 1.25MHz), regardless of if the
load current is high or low.
For AP3436A, the regulator operates in either fixed
PWM mode or a pulse-skipping modulation (PSM)
mode depending on the different load conditions.
The device can operate at typical 1.25MHz fixed
switching frequency under heavy load condition. At
light load, the regulator enters a PSM mode to
minimize the switching loss by reducing the
switching frequency.
The AP3436/A provides EN function. Pulling this
pin high statically enables the device while pulling
the pin low statically for longer than 10µs will shut it
down.
Under Voltage Lockout is internally set at 2.75V for
V_CC detection. The output voltage startup ramp is
controlled by the soft start. An open drain power
good signal indicates the output is within 75% to
125% of its nominal voltage.
The AP3436/A is available in DFN-3×3-10 package.
Features
• Analog Power Input V_CC Range: 3.0V to 5.5V
• Power Input V_IN Range: 1.3V to 5.5V
• 0.6V Reference Voltage with ±1.5% Precision
• 2 MOSFETs (Typ 50mΩ) for High Efficiency at
3A Loads
• High Efficiency: Up to 95%
• Output Current: 3A
• Current Mode Control
• Built-in Soft Start Function
• UV and OV Power Good Output
• Built-in UV and OV Protection Function
• Built-in Over Current Protection
• Built-in Thermal Shutdown Function
• Thermally Enhanced 3mm×3mm DFN Package
Applications
• Desktop & Notebook
• Low Voltage, High Density Power System
• Consumer Application Such as Set Top Box,
LCD Display and CPE Equipment
Jan. 2013 Rev. 1.2
DFN-3×3-10
Figure 1. Package Type of AP3436/A
BCD Semiconductor Manufacturing Limited
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