AP1507
150KHz, 3A PWM BUCK DC/DC CONVERTER
Features
• • • • • • • • • • • • • Output Voltage: 3.3V, 5V, 12V and Adjustable Output Version Adjustable Version Output Voltage Range, 1.23V to 18V+4% 150KHz +15% Fixed Switching Frequency Voltage Mode Non-Synchronous PWM Control Thermal-Shutdown and Current-Limit Protection
General Description
The AP1507 is a monolithic IC designed for a step-down DC/DC converter and is capable of driving a 3A load without an external transistor. Due to reducing the number of external components, the board space can be saved easily. The external shutdown function can be controlled by logic level and then come into standby mode. The internal compensation makes the feedback control have good line and load regulation without an external design. Regarding the protected function, the thermal shutdown is to prevent over temperature operating from damaging the device, and current limit is against over current operating of the output switch. If the current limit function occurred and VFB is down to 0.5V below, the switching frequency will be reduced. The AP1507 series operates at a switching frequency of 150KHz thus allowing smaller sized filter components than what would be needed with lower frequency switching regulators. Other features include a guaranteed +4% tolerance on output voltage under specified input voltage and output load conditions, and +15% on the oscillator frequency. The output version included a fixed 3.3V, 5V, 12V, and an adjustable type. AP1507 is available in a 5-lead TO-252 lead-free package.
ON /OFF Shutdown Control Input Operating Voltage can be up to 22V Output Load Current: 3A Lead Free Package: TO252-5L Low Power Standby Mode Built-in Switching Transistor On Chip Lead Free Package: TO252-5L Lead Free Finish/RoHS Compliant (Note 1)
Applications
• • • Simple High-Efficiency Step-Down Regulator On-Card Switching Regulators Positive to Negative Converter
Ordering Information
AP1507 - XX X X X Output Version Blank : Adjustable 33 : 3.3V 50 : 5.0V 12 : 12V
Note: 1.
Package D5: TO252-5L
Lead Free L : Lead Free
Packing -U : Tube -13 : Taping
RoHS revision 13.2.2003. Glass and High Temperature Solder Exemptions Applied, see EU Directive Annex Notes 5 and 7.
Device
Lead-free
Package Code
D5
Packaging (Note 2)
TO252-5L
Tube/Bulk Part Number Quantity Suffix
80 -U
13” Tape and Reel Part Number Quantity Suffix
2500/Tape & Reel -13
AP1507-XXD5
Note: 2. Pad layout as shown on Diodes Inc. suggested pad layout document AP02001, which can be found on our website at http://www.diodes.com/datasheets/ap02001.pdf.
AP1507 Rev. 1
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AP1507
150KHz, 3A PWM BUCK DC/DC CONVERTER
Pin Assignments
Pin Descriptions
(Top View) 5 SD 4 FB 3 GND 2 Output 1 VIN
Metal Tab GND
Name VIN Output GND FB SD
Description Operating Voltage Input Switching Output Ground Output Voltage Feedback Control
ON /OFF Shutdown
TO252-5L
Block Diagram
SD
VIN
200mV Current Source Bias 1.235V Reference 2.5V Regulator Start Up 220mV
+ Comp _
Comp +
FB
Comp +
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_
+ Amp _
Frequency Compensation
PreDriver
150kHz OSC.
Thermal Shutdown
_
3A Switch
Output GND
FEBRUARY 2007
© Diodes Incorporated
AP1507
150KHz, 3A PWM BUCK DC/DC CONVERTER
Absolute Maximum Ratings
Symbol VCC VSD VFB VOUT PD TST TOP VOP Parameter Supply Voltage
ON /OFF Pin Input Voltage Feedback Pin Voltage Output Voltage to Ground Power Dissipation Storage Temperature Operating Temperature Operating Voltage
Rating +24 -0.3 to +18 -0.3 to +18 -1 Internally Limited -65 to +150 -40 to +125 +4.5 to +22
Unit V V V V W o C o C V
Electrical Characteristics
(All Output Voltage Versions)
Unless otherwise specified, VIN = 12V for 3.3V, 5V, adjustable version and VIN = 18V for the 12V version. ILOAD = 0.5A Specifications with boldface type are for full operating temperature range, the other type are for TJ = 25ºC.
Symbol IFB FOSC FSCP VSAT DC ICL ILEAK IQ ISTBY VIL VIH IH IL ΘJC ΘJA
Parameter Feedback Bias Current Oscillator Frequency
Conditions VFB = 1.3V ( Adjustable Version Only )
Min.
Typ. -10
127 110 10
150 30 1.4 100 0
Max. -50 -100 173 173 50 1.6 1.7
Unit nA KHz KHz V %
When current limit Occurred and VFB < 0.5V, Ta = 25 oC IOUT = 3A Saturation Voltage No Outside Circuit VFB = 0V Force Driver On Max. Duty Cycle (ON) VFB = 0V Force Driver On Min. Duty Cycle (OFF) VFB = 12V Force Driver Off Peak Current Current Limit No Outside Circuit VFB = 0V Force Driver On Output No Outside Circuit Output = 0V leakage VFB =12V Force Driver Off current VIN = 22V Output = -1V Quiescent Current VFB = 12V Force Driver Off Standby Quiescent ON /OFF Pin = 5V Current VIN = 22V ON /OFF Pin Logic Input Low (Regulator ON) High (Regulator OFF) Threshold Voltage Oscillator Frequency of Short Circuit Protect
ON /OFF Pin Logic Input Current
3.6
4.5
5.5 6.5 -200
A uA mA mA uA V
-5 5 70 2.0 1.3
10 150 200 0.6 -0.01
VLOGIC = 2.5V (OFF) -0.1 10 50
uA
o
ON /OFF Pin Input Current VLOGIC = 0.5V (ON) Junction to Thermal Resistance TO252-5L Case Thermal Resistance Junction to TO252-5L with copper area of Ambient approximately 2cm ×2cm
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-1 C/W C/W
o
AP1507 Rev. 1
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AP1507
150KHz, 3A PWM BUCK DC/DC CONVERTER
Electrical Characteristics (Continued)
Specifications with boldface type are for full operating temperature range, the other type are for TJ = 25ºC.
Symbol
VFB
Parameter Output Feedback Efficiency Output Voltage Efficiency Output Voltage Efficiency Output Voltage Efficiency
Conditions 5V < VIN < 22V 0.2A < ILOAD < 3A VOUT Programmed for 3V VIN = 12V, ILOAD = 3A 5.5V < VIN < 22V 0.2A < ILOAD < 3A VIN = 12V, ILOAD = 3A 8V < VIN < 22V 0.2A < ILOAD < 3A VIN = 12V, ILOAD = 3A 15V < VIN < 22V 0.2A < ILOAD < 3A VIN = 16V, ILOAD = 3A
VMin 1.193 1.18
Typ 1.23 74
VMax 1.267 1.28
Unit V %
AP1507-ADJ
η
AP1507-3.3V
VOUT η VOUT η VOUT η
3.168 3.135 4.8 4.75 11.52 11.4
3.3 75 5 80 12 89
3.432 3.465 5.2 5.25 12.48 12.6
V % V % V %
AP1507-5V
AP1507-12V
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AP1507
150KHz, 3A PWM BUCK DC/DC CONVERTER
Typical Performance Characteristics
AP1507 Efficiency vs. Temperature (Vin = 12V, Vout = 5V, Io = 3A)
83 82 81 80 79 78 77 76 75 74 73 72 -50 -30 -10 10 30 50 70 90 110 130 150
AP1507 Efficiency vs. Temperature (Vin = 12V, Vout = 3.3V, Io = 3A)
78 77 76
Efficiency (%)
Efficiency (%)
75 74 73 72 71 70 -50 -30 -10 10 30 50 70 90 110 130 150
Temperature (TA) (°C)
Temperature (TA) (°C)
AP1507 Saturation Voltage vs. Temperature (Vcc = 12V, Vfb = 0V, VSD = 0)
1.6 1.5
AP1507 Switch Current Limit vs. Temperature (Vcc = 12V, Vfb = 0V)
5.5
Saturation Voltage (V)
1.4 1.3 1.2 1.1 1 0.9 0.8 0.7 -50 -25 0 25 1A 0.5A
3A 2A
Switch Current Limit (A)
5 4.5 4 3.5 3 -50 -30 -10 10 30 50 70 90
50
75
100
125
Temperature (TA) (°C)
Temperature (TA) (°C)
AP1507 Supply Current vs. Temperature (Vcc = 12V, No Load, Von/off = 0V (Switch ON), Von/off = 5V (Switch OFF))
15 14 13 12 11 10 9 8 7 6 5
60
Supply Current (mA)
Supply Current (uA)
55 50 45 40 35 30 -50 -30 -10 10 30 50 70 90 110 130 150 Switch OFF
Switch ON
-50 -30 -10 10
30
50
70
90 110 130 150
Temperature (TA) (°C)
Temperature (TA) (°C)
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AP1507
150KHz, 3A PWM BUCK DC/DC CONVERTER
Typical Performance Characteristics (Continued)
AP1507 Threshold Voltage vs. Temperature (Vcc = 12V, Io = 100mA)
1.7 1.6 1.5 1.4 1.3 1.2 1.1 1 0.9 0.8 -50 -30 -10 10 30 50 70 90 110 130 150
AP1507 ON/OFF Current vs. ON/OFF Voltage (Vin= 12V)
10 0 -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 0 3 6 9 12 15 18 21
Threshold Voltage (V)
Temperature (TA) (°C)
ON/OFF Current (nA)
ON/OFF Voltage (V)
AP1507 Frequency vs. Temperature (Vcc = 12V, Io = 500mA, Vout = 5V)
170
AP1507 Feedback Current vs. Temperature (Vcc = 12V, Vout = 5V, Vfb = 1.3V)
10
160 155 150 145 140 -50 -30 -10 10
Feedback Current (nA)
165
0 -10 -20 -30 -40 -50
Frequency (KHz)
Temperature (TA) (°C)
30
50
70
90 110 130 150
-50 -30 -10 10
Temperature (TA) (°C)
30
50
70
90 110 130 150
AP1507 Output Voltage vs. Temperature (Vin = 12V, Io = 3A)
3.5 3.45 3.4 3.35 3.3 3.25 3.2 3.15 3.1 3.05 3 2.95 2.9 -40 -20 0
Vout (V)
Temperature (TA) (°C)
20
40
60
80 100 120 140 160
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AP1507
150KHz, 3A PWM BUCK DC/DC CONVERTER
Typical Application Circuit
(1) Fixed Type Circuit
12V DC Input Vin Cin Capacitor 1 5
FB
4
AP1507 -33 3 SD
2
Output
L1 33uH Inductor D1 Schottky Diode
3.3V/3A Output Load
GND
Co Capacitor
(2) Adjustable Type Circuit
R2 FB 12V DC Input Vin Cin Capacitor 4 1 AP1507 5 SD 3 GND D1 Schottky Diode Co Capacitor 2 Output L1 47uH 5V/ 3A Output Load R1
Vout = VFB × (1 + VFB = 1.23V R2 = 1K ~ 3K (3) Delay Start Circuit
R2 FB 12V DC Input CDELAY 0.1uF Vin 4 1 5 SD RDELAY 10K AP1507 3 2
R1 R2
)
R1
Output
L1 47uH
5V/ 3A Output Load
Cin Capacitor
GND
D1 Schottky Diode
Co Capacitor
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AP1507
150KHz, 3A PWM BUCK DC/DC CONVERTER
Applications Information
Pin Functions +VIN This is the positive input supply for the IC switching regulator. A suitable input bypass capacitor must be present at this pin to minimize voltage transients and to supply the switching currents needed by the regulator. Ground Circuit ground. Output Internal switch. The voltage at this pin switches between (+VIN – VSAT) and approximately – 0.5V, with a duty cycle of approximately VOUT / VIN. To minimize coupling to sensitive circuitry, the PC board copper area connected to this pin should be kept at a minimum. Feedback (FB) Senses the regulated output voltage to complete the feedback loop.
The AP1507 (TO-252 package) junction temperature rises above ambient temperature with a 3A load for various input and output voltages. This data was taken with the circuit operating as a buck-switching regulator with all components mounted on a PC board to simulate the junction temperature under actual operating conditions. This curve can be used for a quick check for the approximate junction temperature for various conditions, but there are many factors that can affect the junction temperature. When load currents higher than 3A are used, double sided or multi-layer PC boards with large copper areas and/or airflow might be needed, especially for high ambient temperatures and high output voltages. For the best thermal performance, wide copper traces and generous amounts of printed circuit board copper should be used in the board layout. (One exception to this is the output (switch) pin, which should not have large areas of copper.) Large areas of copper provide the best transfer of heat (lower thermal resistance) to the surrounding air, and moving air lowers the thermal resistance even further. Package thermal resistance and junction temperature rise numbers are all approximate, and there are many factors that will affect these numbers. Some of these factors include board size, shape, thickness, position, location, and even board temperature. Other factors are trace width, total printed circuit copper area, copper thickness, single or double-sided, multi-layer board and the amount of solder on the board. The effectiveness of the PC board to dissipate heat also depends on the size, quantity and spacing of other components on the board, as well as whether the surrounding air is still or moving. Furthermore, some of these components such as the catch diode will add heat to the PC board and the heat can vary as the input voltage changes. For the inductor, depending on the physical size, type of core material and the DC resistance, it could either act as a heat sink taking heat away from the board, or it could add heat to the board.
ON /OFF (SD)
Allows the switching regulator circuit to be shutdown using logic level signals thus dropping the total input supply current to approximately 150uA. Pulling this pin below a threshold voltage of approximately 1.3V turns the regulator on, and pulling this pin above 1.3V (up to a maximum of 18V) shuts the regulator down. If this shutdown feature is not needed, the ON /OFF pin can be wired to the ground pin.
Thermal Considerations The TO-252 surface mount package tab is designed to be soldered to the copper on a printed circuit board. The copper and the board are the heat sink for this package and the other heat producing components, such as the catch diode and inductor. The PC board copper area that the package is soldered 2 to should be at least 0.8 in , and ideally should have 2 or more square inches of 2 oz. additional copper area which improves the thermal characteristics. With copper areas greater than 2 approximately 6 in , only small improvements in heat dissipation are realized. If further thermal improvements are needed, double sided, multi-layer PC board with large copper areas and/or airflow will be recommended.
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AP1507
150KHz, 3A PWM BUCK DC/DC CONVERTER
Marking Information
TO252-5L
(Top view) Part Number Output Type: Blank: Adjustable 33: 3.3V 50: 5.0V 12: 12V
1507 - XX X X X X XX
Logo L: Lead Free Package ID Code Xth Week:01~52 Year: "01" = 2001 "02" = 2002
~
Package Information ( in mm )
Package Type: TO252-5L
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AP1507
150KHz, 3A PWM BUCK DC/DC CONVERTER
IMPORTANT NOTICE Diodes Incorporated and its subsidiaries reserve the right to make modifications, enhancements, improvements, corrections or other changes without further notice to any product herein. Diodes Incorporated does not assume any liability arising out of the application or use of any product described herein; neither does it convey any license under its patent rights, nor the rights of others. The user of products in such applications shall assume all risks of such use and will agree to hold Diodes Incorporated and all the companies whose products are represented on our website, harmless against all damages. LIFE SUPPORT Diodes Incorporated products are not authorized for use as critical components in life support devices or systems without the expressed written approval of the President of Diodes Incorporated.
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