Diodes AP3407A User Manual
1.2A, 1.4MHz High Efficiency Synchronous DC-DC Buck Converter AP3407/A
Data Sheet
General Description
The AP3407/A is a 1.4MHz fixed frequency, current
mode, PWM synchronous buck (step-down) DC-DC
converter, capable of driving a 1.2A load with high
efficiency, excellent line and load regulation. The
device integrates synchronous P-channel and
N-channel power MOSFET switches with low
on-resistance. It is ideal for powering portable
equipment that runs from a single Li-ion battery.
A standard series of inductors are available from
several different manufacturers optimized for use
with the AP3407/A. This feature greatly simplifies
the design of switch-mode power supplies.
The AP3407/A is available in SOT-23-5.
Features
Input Voltage Range: 2.5V to 5.5V
•
• Output Voltage: 0.6V to V
• ADJ Output
• Fixed 1.4MHz Frequency
• High Efficiency up to 95%
• Output Current: 1.2A
• Current Mode Control
• 100% Duty Cycle in Dropout
• Built-in Over Current Protection
• Built-in Short Circuit Protection
• Built-in Thermal Shutdown Protection
• Built-in UVLO Function
• Built-in Soft-start
IN
Applications
• Datacom
• Portable Device
• Smart Phone
SOT-23-5
Figure 1. Package Type of AP3407/A
Dec. 2011 Rev. 1. 3 BCD Semiconductor Manufacturing Limited
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Data Sheet
1.2A, 1.4MHz High Efficiency Synchronous DC-DC Buck Converter AP3407/A
Pin Configuration
K Package
(SOT-23-5)
1
EN
GND
2
SW
34
(For AP3407) (For AP3407A)
Pin Description
Pin Number
AP3407 AP3407A
1 3 EN
2 2 GND Ground pin
3 5 SW
5
FB
VIN
1
VIN
GND
2
EN
34
Figure 2. Pin Configuration of AP3407/A (Top View)
Pin Name Function
Control input pin. Forcing this pin above 1.5V enables
the IC. Forcing this pin below 0.4V shuts down the IC.
When the IC is in shutdown mode, all functions are
disabled to decrease the supply current below 1.2A
Power switch output pin. Inductor connection to drain
of the internal PFET and NFET switches
5
SW
FB
4 1 VIN
5 4 FB
Supply input pin. Bypass to GND with a 4.7µF or
greater ceramic capacitor
This is the feedback pin of the device. Connect this pin
directly to the output if the fixed output voltage version
is used. For the adjustable version an external resistor
divider is connected to this pin.
Dec. 2011 Rev. 1. 3 BCD Semiconductor Manufacturing Limited
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Data Sheet
1.2A, 1.4MHz High Efficiency Synchronous DC-DC Buck Converter AP3407/A
Functional Block Diagram
Figure 3. Functional Block Diagram of AP3407/A
Dec. 2011 Rev. 1. 3 BCD Semiconductor Manufacturing Limited
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Data Sheet
1.2A, 1.4MHz High Efficiency Synchronous DC-DC Buck Converter AP3407/A
Ordering Information
AP3407 -
G1: Green
Circuit Type
Blank: AP3407
TR: Tape & Reel
A: AP3407A
K: SOT-23-5
Package
SOT-23-5 -40 to 85 ºC
BCD Semiconductor's Pb-free products, as designated with "G1" suffix in the part number, are RoHS compliant
and green.
Temperature
Range
Part Number Marking ID
Green Green
AP3407KTR-G1 GJA Tape & Reel
AP3407AKTR-G1 GJB Tape & Reel
Packing Type
Absolute Maximum Ratings (Note 1)
Parameter Symbol Value Unit
Input Voltage VIN -0.3 to 6.0 V
Feedback Voltage VFB -0.3 to VIN +0.3 V
EN Pin Voltage VEN -0.3 to VIN+0.3 V
SW Pin Voltage VSW -0.3 to VIN+0.3 V
Thermal Resistance
Thermal Resistance
θ
JA
θ
JC
265 ºC/W
60 ºC/W
Power Dissipation PD 0.377 W
Operating Junction Temperature TJ 150 ºC
Storage Temperature T
Lead Temperature (Soldering, 10sec) T
Note 1: Stresses greater than those listed under “Absolute Maximum Ratings” may cause permanent damage to
the device. These are stress ratings only, and functional operation of the device at these or any other conditions
beyond those indicated under “Recommended Operating Conditions” is not implied. Exposure to “Absolute
Maximum Ratings” for extended periods may affect device reliability.
Note 2: The junction temperature rise is given by T
θ
is the thermal resistance from junction of the die to the ambient temperature; The junction temperature, TJ is
JA
given by T
J=TA+TR
, where TA is the ambient temperature.
RISING=PD
-65 to 150 ºC
STG
260 ºC
LEAD
*θJA, where PD is the power dissipated by regulator,
Dec. 2011 Rev. 1. 3 BCD Semiconductor Manufacturing Limited
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