Diodes AP6507 User Manual
NEW PRODUCT
F
F
C
C
Y
500 kHz 18V 3A SYNCHRONOUS DC/DC BUCK CONVERTER
Description
The AP6507 is a 500kHz switching frequency internal
compensated synchronous DCDC buck converter. It has
integrated compensation, and low R
high and low side
DSON
MOSFETs.
The AP6507 enables continues load current of up to 3A with
efficiency as high as 93%.
The AP6507 features current mode control operation, which
enables fast transient response times and easy loop
stabilization.
The AP6507 simplifies board layout and reduces space
requirements with its high level of integration and minimal
need for external components, making it ideal for distributed
power architectures.
The AP6507 is available in a standard Green SO-8EP
package with exposed PAD for improved thermal
performance and is RoHS compliant.
Features
Pin Assignments
1
IN
SW
BST
2
3
4
Applications
(Top View)
SO-8EP
AP6507
8
GND
V
7
CC
6
FBSW
5
EN
• VIN 4.5V to 18V
• V
adjustable to 0.8V
OUT
• 500kHz switching frequency
• Enable pin
• Protection:
o OCP
o Thermal Shutdown
• Lead Free Finish/ RoHS Compliant (Note 1)
Note: 1. EU Directive 2002/95/EC (RoHS). All applicable RoHS exemptions applied. Please visit our website at
http://www.diodes.com/products/lead_free.html
.
• Gaming Consoles
• TV sets and Monitors
• Set Top Boxes
• Distributed power systems
• Home Audio
• Consumer electronics
Typical Application Circuit
100
90
80
(%)
70
IEN
I
60
E
V = 2.5V
OUT
50
40
0
1
LOAD CURRENT (A)
Efficiency vs. Load Current
AP6507
Document number: DS33435 Rev. 3 - 2
V = 12V
IN
V = 5V
IN
2
3
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Pin Descriptions
Pin # Name Description
1 IN
2, 3 SW Switch Output. Use wide PCB trace to make the connection.
4 BST
5 EN
6 FB
7
8
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Functional Block Diagram
V
CC
GND
Exposed PAD
AP6507
500 kHz 18V 3A SYNCHRONOUS DC/DC BUCK CONVERTER
Supply Voltage. The AP6507 operates from a 4.5V to 18V input rail. C1 is needed to
decouple the input rail. Use wide PCB trace to make the connection.
Bootstrap. A capacitor connected between SW and BS pins is required to form a floating
supply across the high-side switch driver.
EN=1 to enable the chip. For automatic start-up, connect EN pin to VIN by proper EN resistor
divider as Figure 1 shows.
Feedback. An external resistor divider from the output to GND, tapped to the FB pin, sets the
output voltage. To prevent current limit run away during a short circuit fault condition the
frequency fold-back comparator lowers the oscillator frequency when the FB voltage is below
500mV.
BIAS Supply. Decouple with 0.1μF – 0.22μF cap. The capacitance should be no more than
0.22μF
System Ground. This pin is the reference ground for the regulated output voltage. For this
reason care must be taken in its PCB layout. Suggested to be connected to GND with copper
and vias.
AP6507
Document number: DS33435 Rev. 3 - 2
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AP6507
Absolute Maximum Ratings (T
Symbol Parameter Rating Unit
VIN
VSW
VBS
VFB
VEN
V
COMP
TST
TJ
TL
ESD Susceptibility (Note 3)
HBM Human Body Model 3 kV
MM Machine Model 300 V
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Thermal Resistance (Note 4)
Symbol Parameter Rating Unit
θ
JA
θ
JC
Recommended Operating Conditions (Note 5)
Symbol Parameter Min Max Unit
VIN
TA
Notes: 2. Stresses greater than the 'Absolute Maximum Ratings' specified above, may cause permanent damage to the device. These are stress ratings
only; functional operation of the device at these or any other conditions exceeding those indicated in this specification is not implied. Device
reliability may be affected by exposure to absolute maximum rating conditions for extended periods of time.
3. Semiconductor devices are ESD sensitive and may be damaged by exposure to ESD events. Suitable ESD precautions should be taken when
handling and transporting these device.
4. Test condition for SO-8EP: Device mounted on 2"*2" FR-4 substrate PC board, 2oz copper, with minimum recommended pad on top layer and
thermal vias to bottom layer ground plane.
5. The device function is not guaranteed outside of the recommended operating conditions.
Supply Voltage
Switch Node Voltage -0.3 to 20 V
Bootstrap Voltage
Feedback Voltage –0.3 to +6 V
Enable/UVLO Voltage –0.3 to +6 V
Comp Voltage –0.3 to +6 V
Storage Temperature -65 to +150 °C
Junction Temperature +150 °C
Lead Temperature +260 °C
Junction to Ambient 56 °C/W
Junction to Case 16 °C/W
Supply Voltage
Operating Ambient Temperature Range
500 kHz 18V 3A SYNCHRONOUS DC/DC BUCK CONVERTER
= 25°C)
A
19
VSW + 6
4.5
-40
18 V
+85 °C
V
V
AP6507
Document number: DS33435 Rev. 3 - 2
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Electrical Characteristics (V
Symbol Parameter Test Conditions Min Typ. Max Unit
IIN
IIN
R
DS(ON)1
R
DS(ON)2
SW
LKG
I
Limit
FSW
FFB
D
MAX
VFB
IFB
V
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EN_Rising
V
EN_HYS
IEN
EN
TD-Off
INUV
INUV
HYS
VCC
VCC Load Regulation Icc=5mA 5 %
Soft-Start Period 2 ms
TSD
Note: 6. Guaranteed by design
AP6507
Document number: DS33435 Rev. 3 - 2
Shutdown Supply Current
Supply Current (Quiescent)
High-Side Switch On-Resistance
(Note 6)
Low-Side Switch On-Resistance
(Note 6)
Switch Leakage Current
Current Limit 5.8 A
Oscillator Frequency
Fold-back Frequency
Maximum Duty Cycle
Feedback Voltage
Feedback Current
EN Rising Threshold 1.1 1.3 1.5 V
EN Threshold Hysteresis 0.4 V
EN Input Current
EN Turn Off Delay (Note 6) 5 μs
V
Vth
Under Voltage Threshold Rising
IN
V
Under Voltage Threshold
IN
Hysteresis
VCC Regulator 5 V
Thermal Shutdown 140 °C
AP6507
500 kHz 18V 3A SYNCHRONOUS DC/DC BUCK CONVERTER
= 12V, TA = +25°C, unless otherwise noted)
IN
VEN = 0V
VEN = 2.0V, VFB = 1.0V
120 mΩ
20 mΩ
V
= 0V, VSW = 0V
EN
V
= 0.75V
FB
V
= 300mV
FB
VFB = 700mV
TA = -40°C to +85°C
V
= 800mV
FB
V
= 2V
EN
VEN = 0V
4.0 4.2 4.4 V
200 mV
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15 µA
1.2 mA
0 10 µA
350 500 650 kHz
0.3
80 85 %
788 808 828 mV
10 50 nA
2
0
© Diodes Incorporated
fSW
μA
October 2011
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