AP65450EV1-EVM

AP65450EV1
650kHz, 18V, 4A, COT Synchronous DC/DC Buck Converter
in SO-8EP
Description
The AP65450 is an adaptive on-time mode
synchronous buck converter providing high
efficiency, excellent transient response and
high DC output accuracy for low-voltage
regulation in digital TV and monitor.
The constant-on-time control scheme
handles wide input/output voltage ratios and
provides low external component count. The
internal proprietary circuit enables the
device to adopt both low equivalent series
resistance (ESR) output capacitors, such as
SP-CAP or POSCAP and ultra-low ESR
ceramic capacitors.
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Gaming Consoles
Flat Screen TV Sets and Monitors
Set Top Boxes
Distributed Power Systems
Green Electronics
The adaptive on-time control supports
seamless transition between continuous
conduction mode (CCM) at higher load
conditions and discontinuous conduction
mode (DCM) at lighter load conditions.
DCM allows AP65450 maintain high
efficiency at light load conditions. The
AP65450 also features programmable softstart, UVLO, OTP and OCP to protect the
circuit.
This IC is available in SO-8EP package.
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Home Audio
Consumer Electronics
Network Systems
FPGA, DSP and ASIC Supplies
Performance Spec of AP65450EV1 (Rev2)
Parameter
Conditions
Input voltage
Range 4.5V to 18V
Output Current
Output Voltage
Output Voltage Ripple
Peak-to-peak Deviation
Transient Response
Load step from 0A to 4A
Switching Frequency
Efficiency
AP65450EV1
Document number: Rev. 2.0
Performance Value
12V
4A
1.05V
20mVP-P
30mVP-P
650kHz
90%
@VOUT=5V
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© Diodes Incorporated
AP65450EV1
650kHz, 18V, 4A, COT Synchronous DC/DC Buck Converter
in SO-8EP
Figure 1. Evaluation Board (Rev2)
Figure 2. Load Transient 0 to 4A
Figure 3. Efficiency
Figure 4. Light Load Efficiency
VO=2.5V
VO=1.8V
VO=1.5V
VO=1.2V
VO=3.3V
VO=5V
VO=1.05V
PCB Layouts
Top Layer
AP65450EV1
Document number: Rev. 2.0
Bottom Layer
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September 2014
© Diodes Incorporated
AP65450EV1
650kHz, 18V, 4A, COT Synchronous DC/DC Buck Converter
in SO-8EP
Quick Start Guide
The AP65450EV1 has a simple layout and allows access to the appropriate signals through test
points. To evaluate the performance of the AP65450, follow the procedure below:
1. Connect a power supply to the input terminals VIN and GND. Set VIN to 12V.
2. Connect the positive terminal of the electronic load to VOUT and negative terminal to GND.
3. EN has a positive voltage through a 100K pull-up to VIN. No supply input is required for EN.
Note: To use the EN function drive EN above 1.9V to start the converter and below 0.6V
to stop the converter.
4. The evaluation board should now power up with a 1.05V output voltage.
5. Check for the proper output voltage of 1.05V (±1%) at the output terminals VOUT and GND.
Measurement can also be done with a multimeter with the positive and negative leads
between VOUT and GND.
6. Set the load to 4A through the electronic load. Check for the stable operation of the SW
signal on the oscilloscope. Measure the switching frequency. A test point is conveniently
located at the head of the inductor.
Measurement/Performance Guidelines:
1) When measuring the output voltage ripple, maintain the shortest possible ground lengths
on the oscilloscope probe. Long ground leads can erroneously inject high frequency
noise into the measured ripple.
2) For efficiency measurements, connect an ammeter in series with the input supply to
measure the input current. Connect an electronic load to the output for output current.
AP65450EV1
Document number: Rev. 2.0
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September 2014
© Diodes Incorporated
AP65450EV1
650kHz, 18V, 4A, COT Synchronous DC/DC Buck Converter
in SO-8EP
EVALUATION BOARD SCHEMATIC
BILL OF MATERIALS
REF
VALUE
DESCRIPTION
PACKAGE
MANUFACTURER
MANUFACTURER P/N
C1,
C2
C4
10µF
Ceramic Cap, 25V, X5R
1210
Murata
GRM32DR61E106KA12L
8.2nF
0805
AVX
0805YC822KAT2A
C5
1µF
Ceramic Capacitor,
16V, X7R
Ceramic Cap, 16V, X7R
0805
Kemet
C0805C105K4RACTU
C6
0.1µF
0805
Samsung
CL21B104KACNNNC
C8,
C9
L1
22µF
Ceramic Capacitor, 25V,
X7R
Ceramic Cap, 25V, X5R
1210
AVX
12103D226KAT2A
SMD
Wurth
744311150
R1
8.25kΩ
Inductor, SMD
6.9mmWx6.9mmLx4mmH
Resistor, 1%
0805
Panasonic
ERJ-6ENF8251V
R2
22.1kΩ
Resistor, 1%
0805
Panasonic
ERJ-6ENF2212V
R3
100kΩ
Resistor, 1%
0805
Panasonic
ERJ-6ENF1003V
DC/DC Converter
SO-8EP
Diodes Inc
AP65450SP
1.5µH
U1
AP65450EV1
Document number: Rev. 2.0
4 of 5
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September 2014
© Diodes Incorporated
AP65450EV1
650kHz, 18V, 4A, COT Synchronous DC/DC Buck Converter
in SO-8EP
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Copyright © 2014, Diodes Incorporated
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AP65450EV1
Document number: Rev. 2.0
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