AP1501-ADJ

Part: AP1501 from Diodes Incorporated

Type: PWM Buck DC/DC Converter

Key Specs:

• Output Load Current: 3A
• Switching Frequency: 150kHz
• Operating Voltage: up to 40V
• Adjustable Output Voltage Range: 1.23V to 37V
• Fixed Output Voltages: 3.3V, 5.0V, 12V
• Output Voltage Tolerance: +/- 4%
• Oscillator Frequency Tolerance: +/- 15%

Features:

• Output Voltage: 3.3V, 5V, 12V and Adjustable Output Version
• Adjustable Version Output Voltage Range, 1.23V to 37V+4%
• 150kHz +15% Fixed Switching Frequency
• Voltage Mode Non-Synchronous PWM Control
• Thermal-Shutdown and Current-Limit Protection
• ON/OFF Shutdown Control Input
• Operating Voltage can be up to 40V
• Output Load Current: 3A
• Low Power Standby Mode
• Built-In Switching Transistor on Chip
• TO263-5 and TO220-5 Packages
• Totally Lead-Free & Fully RoHS Compliant
• Halogen- and Antimony-Free. "Green" Device

Applications:

• Simple High-Efficiency Step-Down Regulator
• On-Card Switching Regulators
• Positive to Negative Converter

Package:

• TO263-5: dimensions not specified
• TO220-5: dimensions not specified

• Output Voltage: 3.3V, 5V, 12V and Adjustable Output Version
• Adjustable Version Output Voltage Range, 1.23V to 37V+4%
• 150kHz +15% Fixed Switching Frequency
• Voltage Mode Non-Synchronous PWM Control
• Thermal-Shutdown and Current-Limit Protection
• ON/OFF Shutdown Control Input
• Operating Voltage can be up to 40V
• Output Load Current: 3A
• Low Power Standby Mode
• Built-In Switching Transistor on Chip
• TO263-5 and TO220-5 Packages
• Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)
• Halogen- and Antimony-Free. "Green" Device (Note 3)
• For automotive applications requiring specific change control (i.e. parts qualified to AEC-Q100/101/200, PPAP capable, and manufactured in IATF 16949 certified facilities), please contact us or your local Diodes representative.

https://www.diodes.com/quality/product-definitions/

• Simple High-Efficiency Step-Down Regulator

• On-Card Switching Regulators

• Positive to Negative Converter

• Notes: 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS), 2011/65/EU (RoHS 2) & 2015/863/EU (RoHS 3) compliant.

  • 2. See https://www.diodes.com/quality/lead-free/ for more information about Diodes Incorporated's definitions of Halogen- and Antimony-free, "Green" and Lead-free.
  • 1. Halogen- and Antimony-free "Green" products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and <1000ppm antimony compounds.

( Top View )

TO220-5L/TO220-5L(R) TO220-5L

Unless otherwise specified, VIN = 12V for 3.3V, 5V, adjustable version and VIN = 24V for the 12V version. ILOAD = 0.5A Specifications with boldface type are for full operating temperature range, the other type are for TJ = +25°C.

Symbol	Parameter		Conditions	Min	Typ.	Max	Unit
			VFB = 1.3V			60
IFB	Feedback Bias Current		— (Adjustable Version Only) (Note 4)	127	40 150	100 173	nA
FOSC	Oscillator Frequency		— IOUT = 3A	110	—	173 1.4	kHz
VSAT	Saturation Voltage		No Outside Circuit VFB = 0V Force Driver On	—	1.3	1.5	V
	Max. Duty Cycle (ON)		VFB = 0V Force Driver On	—	100	—
DC	Min. Duty Cycle (OFF)		VFB = 12V Force Driver Off	—	0	—	%
			Peak Current		4.0	5.5	A
ICL	Current Limit		No Outside Circuit VFB = 0V Force Driver On	3.6		6.5
IL	Output = 0	Output Leakage	—	—	200	200	μA
	Output = -1	Current	—	2	60	60	mA
IQ	Quiescent Current		VFB = 12V Force Driver Off	—	5	10	mA
	Standby Quiescent		ON/OFF Pin = 5V	—		250	μA
ISTBY	Current		VIN = 40V		150	350
VIL			Low (Regulator ON)	—		0.6
VIH	ON/OFF Pin Logic Input Threshold Voltage		High (Regulator OFF)	2.0	1.3	—	V
IH	ON/OFF Pin Logic Input Current		VLOGIC = 2.5V (OFF)	—	15	25	μA
IL	ON/OFF Pin Input Current		VLOGIC = 0.5V (ON)	—	0.02	5
	Thermal Resistance		TO263-5 (Note 5)	—	37	—	°C/W
θJA	Junction to Ambient		TO220-5 (Note 5)	—	31	—
	Thermal Resistance Junction		TO263-5 (Note 5)	—	6	—
θJC	to Case		TO220-5 (Note 5)	—	5	—	°C/W

1. Test condition: Device mounted with copper area of approximately 3 in2 ,1oz, no air flow.

Symbol	Parameter	Rating	Unit
ESD MM	Machine Model ESD Protection	400	V
VCC	Supply Voltage	+45	V
VSD	ON/OFF Pin Input Voltage	-0.3 to +40	V
VFB	Feedback Pin Voltage	-0.3 to +40	V
VOUT	Output Voltage to Ground	-1	V
PD	Power Dissipation	Internally Limited	W
TST	Storage Temperature	-65 to +150	°C
TJ	Operating Junction Temperature	-20 to +125	°C
TMJ	Maximum Junction Temperature	+150	°C

Electrical Characteristics (@ TA = +25°C, unless otherwise specified.)

Unless otherwise specified, VIN = 12V for 3.3V, 5V, adjustable version and VIN = 24V for the 12V version. ILOAD = 0.5A Specifications with boldface type are for full operating temperature range, the other type are for TJ = +25°C.

Symbol	Parameter		Conditions	Min	Typ.	Max	Unit
			VFB = 1.3V			60
IFB	Feedback Bias Current		— (Adjustable Version Only) (Note 4)	127	40 150	100 173	nA
FOSC	Oscillator Frequency		— IOUT = 3A	110	—	173 1.4	kHz
VSAT	Saturation Voltage		No Outside Circuit VFB = 0V Force Driver On	—	1.3	1.5	V
	Max. Duty Cycle (ON)		VFB = 0V Force Driver On	—	100	—
DC	Min. Duty Cycle (OFF)		VFB = 12V Force Driver Off	—	0	—	%
			Peak Current		4.0	5.5	A
ICL	Current Limit		No Outside Circuit VFB = 0V Force Driver On	3.6		6.5
IL	Output = 0	Output Leakage	—	—	200	200	μA
	Output = -1	Current	—	2	60	60	mA
IQ	Quiescent Current		VFB = 12V Force Driver Off	—	5	10	mA
	Standby Quiescent		ON/OFF Pin = 5V	—		250	μA
ISTBY	Current		VIN = 40V		150	350
VIL			Low (Regulator ON)	—		0.6
VIH	ON/OFF Pin Logic Input Threshold Voltage		High (Regulator OFF)	2.0	1.3	—	V
IH	ON/OFF Pin Logic Input Current		VLOGIC = 2.5V (OFF)	—	15	25	μA
IL	ON/OFF Pin Input Current		VLOGIC = 0.5V (ON)	—	0.02	5
	Thermal Resistance		TO263-5 (Note 5)	—	37	—	°C/W
θJA	Junction to Ambient		TO220-5 (Note 5)	—	31	—
	Thermal Resistance Junction		TO263-5 (Note 5)	—	6	—
θJC	to Case		TO220-5 (Note 5)	—	5	—	°C/W

1. Test condition: Device mounted with copper area of approximately 3 in2 ,1oz, no air flow.

Electrical Characteristics (continued) (@ TA = +25°C, unless otherwise specified.)

Specifications with boldface type are for full operating temperature range, the other type are for TJ = +25°C.

—	Symbol	Parameter	Conditions	VMin	Typ.	VMax	Unit
AP1501-ADJ	VFB	Output Feedback	4.5V < VIN < 40V 0.2A < ILOAD < 3A VOUT programmed for 3V	1.193 1.18	1.23	1.267 1.28	V
	η	Efficiency	VIN = 12V, ILOAD = 3A	—	73	—	%
AP1501-3.3V	VOUT	Output Voltage	4.75V < VIN < 40V 0.2A < ILOAD < 3A	3.168 3.135	3.3	3.432 3.465	V
	η	Efficiency	VIN = 12V, ILOAD = 3A	—	73	—	%
AP1501-5V	VOUT	Output Voltage	7V < VIN < 40V 0.2A < ILOAD < 3A	4.8 4.75	5	5.2 5.25	V
	η	Efficiency	VIN = 12V, ILOAD = 3A	—	80	—	%
AP1501-12V	VOUT	Output Voltage	15V < VIN < 40V 0.2A < ILOAD < 3A	11.52 11.4	12	12.48 12.6	V
	η	Efficiency	VIN = 15V, ILOAD = 3A	—	90	—	%

The AP1501 is available in the 5-pin surface mount TO-263 and TO-220.

Under most conditions, the TO-220 package requires a heat sink. The size of the heat sink depends on the input voltage, the output voltage, the load current, and the ambient temperature. The AP1501 junction temperature rises above ambient temperature for a 3A load and different input and output voltages. The data for these curves was taken with the AP1501 (TO-220 package) operating as a buck switching regulator in an ambient temperature of 25°C (still air). These temperature rise numbers are all approximate and there are many factors that can affect these temperatures. Higher ambient temperatures require more heat sinking.

The TO-263 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 to should be at least 0.4 in2 , and ideally should have 2 or more square inches of 2 oz. Additional copper area improves the thermal characteristics, but with copper areas greater than approximately 6 in² , only small improvements in heat dissipation are realized. If further thermal improvements are needed, double-sided multilayer PC boards with large copper areas and/or airflow are recommended.

The AP1501 (TO-263 package) junction temperature rises above ambient temperature with a 2A 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 be aware that there are many factors that can affect the junction temperature. When load currents higher than 2A are used, doublesided or multilayer 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, the board being single or double-sided, the board being multilayered, 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 add heat to the board or act as a heat sink taking heat away from the board.