AP1512/A
50KHz, 2A/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 37V+4% - 50KHz +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 60V - Output load current: 2A (for AP1512) 3A (for AP1512A) - Low power standby mode - Built-in switching transistor on chip - TO220-5L, TO220-5L(R) and TO263-5L Pb-free packages
General Description
The AP1512/A is a monolithic IC that design for a step-down DC/DC converter, and own the ability of driving a 2A (3A for AP1512A) load without additional transistor component. Due to reducing the number of external component, 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 feedback control have good line and load regulation without external design. Regarding protected function, thermal shutdown is to prevent over temperature operating from damage, and current limit is against over current operating of the output switch. The AP1512/A operates at a switching frequency of 50KHz 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 fixed 3.3V, 5V, 12V, and an adjustable type. The packages are available in a standard 5-lead TO-220 package and a 5-lead TO-263.
Applications
- Simple High-efficiency step-down regulator - On-card switching regulators - Positive to negative converter
Pin Assignments
( Top View ) 5 SD 4 FB 3 Gnd 2 Output 1 VIN
Pin Descriptions
Name VIN Output Gnd FB SD Description Operating voltage input Switching output Ground Output voltage feedback control ON/OFF Shutdown
Metal Tab GND
TO263-5L ( Top View ) 5 SD 4 FB 3 Gnd 2 Output 1 VIN TO220-5L
This datasheet contains new product information. Anachip Corp. reserves the rights to modify the product specification without notice. No liability is assumed as a result of the use of this product. No rights under any patent accompany the sale of the product.
Rev.1.1 Oct. 14, 2005 1/12
AP1512/A
50KHz, 2A/3A PWM Buck DC/DC Converter Ordering Information
AP1512 X XX X X Part Number Blank: 2A A : 3A Output Version Blank : Adjustable -33 : 3.3V -50 : 5.0V -12 : 12V Package T5: TO220-5L T5R: TO220-5L(R) K5: TO263-5L Packing Blank : Tube A : Taping
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 _
Frequecy compensation
Pre-driver
50KHz OSC.
Thermal Limit
_
2A Switch (3A for AP1512A)
Output Gnd
Rev.1.1 Oct. 14, 2005
AP1512/A
50KHz, 2A/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 +63 -0.3 to +40 -0.3 to +40 -1 Internally limited -65 to +150 -40 to +125 +4.5 to +60 Unit V V V V W o C o C V
Electrical Characteristics (All Output Voltage Versions)
Unless otherwise specified, VIN=30V for all version. ILOAD = 0.5A
Symbol IB FOSC VSAT DC ICL ICL IL IQ ISTBY VIL VIH IH IL θJC θJA
Parameter Feedback bias current oscillator frequency
Conditions VFB=1.3V (Adjustable version only)
Min.
Typ. 5
42.5 40
50 1.3 100 0
IOUT=2A 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 for AP1512 no outside circuit VFB=0V force driver on peak current current limit for AP1512A no outside circuit VFB=0V force driver on Output no outside circuit Output = 0 leakage VFB=12V force driver off VIN=60V Output = -1 current Quiescent Current VFB=12V force driver off Standby Quiescent ON/OFF pin=5V Current VIN=60V Low (regulator ON) ON/OFF pin logic input threshold voltage High (regulator OFF) ON/OFF pin logic VLOGIC=2.5V (OFF) input current ON/OFF pin input current VLOGIC=0.5V (ON) Junction to TO220-5L Thermal Resistance case TO263-5L TO220-5L Thermal Resistance Junction to With copper area of ambient TO263-5L 2 approximately 3 in saturation voltage
Max. 8 10 57.5 60 1.4 1.5
Unit µA KHz V %
2.5 3.2
3 4
4.5 5.5 5 6 -250
A A uA mA mA uA V uA
o
-2 5 350 2.0 1.3 0 -0.8 2.5 3.5 28 23
-60 10 450 500 0.6 -5 -10
C/W C/W
o
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Rev.1.1 Oct. 14, 2005
AP1512/A
50KHz, 2A/3A PWM Buck DC/DC Converter Electrical Characteristics (Continued)
AP1512 Symbol AP1512-ADJ AP1512-3.3V AP1512-5V
VFB VOUT VOUT VOUT η
Parameter Output Feedback Output voltage Output voltage Output voltage Efficiency Parameter Output Feedback Output voltage Output voltage
Conditions 10V < VIN < 60V 0.2A < ILOAD < 2A VOUT programmed for 3V 10V < VIN < 60V 0.2A < ILOAD < 2A 10V < VIN < 60V 0.2A < ILOAD < 2A 15V < VIN < 60V 0.2A < ILOAD < 2A VIN = 30V, ILOAD = 2A Conditions 10V < VIN < 60V 0.2A < ILOAD VOUT programmed for 3V 10V < VIN < 60V 0.2A < ILOAD 10V < VIN < 60V 0.2A < ILOAD
Typ. 1.23 3.3 5 12 83 Typ. 1.23 3.3 5
Limit 1.193/1.18 1.267/1.28 3.168/3.135 3.432/3.465 4.8/4.75 5.2/5.25 11.52/11.4 12.48/12.6
Unit V VMIN VMAX V VMIN VMAX V VMIN VMAX V VMIN VMAX % Unit V VMIN VMAX V VMIN VMAX V VMIN VMAX V VMIN VMAX %
AP1512-12V
AP1512A Symbol AP1512A-ADJ AP1512A-3.3V AP1512A-5V
VFB VOUT VOUT
Limit 1.193/1.18 1.267/1.28 3.168/3.135 3.432/3.465 4.8/4.75 5.2/5.25
AP1512A-12V
VOUT
η
Output voltage Efficiency
15V < VIN < 60V 0.2A < ILOAD VIN = 30V, ILOAD = 3A
12 80
11.52/11.4 12.48/12.6
Specifications with boldface type are for full operating temperature range, the other type are for TJ=25ºC.
Typical Performance Characteristics
AP1512A Current Limit v.s. Temperature (Vcc=60V, Vout=5V)
4 3.8 Current Limit (A) 3.6 3.4 3.2 3 -50
Efficiency(%)
AP1512A Efficiency v.s. Supply Voltage (Vout=5V, Iout=3A)
100 90 80 70 60 50 40 30 20 10 0 0 12 24 36 Supply Voltage(V) 48 60
0
50
100
150
Temperature (TA) (°C)
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Rev.1.1 Oct. 14, 2005
AP1512/A
50KHz, 2A/3A PWM Buck DC/DC Converter Typical Performance Characteristics (Continued)
AP1512 Efficiency v.s. Temperature (Vin=12V,Vout=5V,Io=2A)
100 90 80 70
AP1512 Efficiency v.s. Temperature (Vin=12V,Vout=3.3V,Io=2A)
100 90 80 70 60 50 40 30 20 10 0 -50 -30 -10 10 30
Efficiency (%)
60 50 40 30 20 10 0 -50 -30 -10 10 30 50 70 90 110 130 150
Efficiency (%)
50 70 90 110 130 150
Temperature (TA) (°C)
Tem perature (TA) (°C)
AP1512 Supply Current v.s. Temperature (Vcc=12V , No Load ,Von/off =0V(Switch ON) ,Von/off =5V(Switch OFF))
8 100 90 Switch ON
Supply Current (mA)
6 5 4 3 2 1 0 -40 -25 -10 5
Supply Current (uA)
7
80 70 60 50 40 30 20 10 0
Switch OFF
20 35
50 65 80 95 110 125
-40 -25 -10
5
20 35 50 65 80 95 110 125
Temperature (TA) (°C)
Temperature (TA) (°C)
AP1512 Output Voltage v.s. Temperature (Vin=12V, Vout=5V, Io=1A)
5.10 5.05
AP1512 Threshold Voltage v.s. Temperature (Vcc=12V, Vout=5V)
1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0 -50 0 50 100 150
Output Voltage (V)
5.00 4.95 4.90 4.85 4.80 4.75 4.70 -50 0 50 100 Temperature (TA) (°C) 150
Threshold Voltage (V)
Temperature (TA) (°C)
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Rev.1.1 Oct. 14, 2005
AP1512/A
50KHz, 2A/3A PWM Buck DC/DC Converter Typical Performance Characteristics (Continued)
AP1512 Frequency v.s. Temperature (Vcc=12V, Io=1A, Vout=5V)
60
AP1512 Current Limit v.s. Temperature (Vcc=60V, Vout=5V)
3.6
Frequency (KHz)
55
50
Current Limit (A)
-50 -30 -10 10 30 50 70 90 110 130 150
3.4
3.2
45
3
40
2.8 -50 0 50 100 150
Temperature (TA) (°C)
Temperature (TA) (°
AP1512 Quiescent Current v.s. Supply Voltage (force driver off)
6.2
Quiescent Current (A)
6 5.8 5.6 5.4 5.2 0 12 24 36 48 60
Supply Voltage(V)
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Rev.1.1 Oct. 14, 2005
AP1512/A
50KHz, 2A/3A PWM Buck DC/DC Converter Typical Application Circuit
(1) Adjustable Type Circuit A. Vin=10V~60V, Vout=5V; Iout=0.3A~2A, Iout below 0.3A DCM
Vin 1 Vin OUTPUT 2 1 L1 47uH 2 Vout
AP1512/A
5 C1 100uF/100V C2 1u ON/OFF SD GND 3 FB 4 D1 SR360 R2 3K C5 1n C7 0.1u C3 470uF/16V
R3 1K
B. Vin=10V~60V, Vout=3.3V, Iout=0.3A~2A, Iout below 0.3A DCM
Vin 1 Vin OUTPUT 2 1 L1 47uH 2 Vout
AP1512/A
5 C1 100uF/100V C2 1u ON/OFF SD GND 3 FB 4 D1 SR360 R2 2K C5 1n C7 0.1u C3 470uF/16V
R3 1.2K
(2) Fixed Type Circuit A. Vin=10V~60V, Vout=5V, Iout=0.7A~2A, Iout below 0.7A DCM
Vin 1 Vin OUTPUT 2 1 L1 47uH 2 Vout
AP1512/A
5 C1 100uF/100V C2 1u ON/OFF SD GND 3 FB 4 D1 SR360
C7 10n
C3 470uF/16V
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Rev.1.1 Oct. 14, 2005
AP1512/A
50KHz, 2A/3A PWM Buck DC/DC Converter Typical Application Circuit (Continued)
B. Vin=10V~60V, Vout=3.3V, Iout=0.7A~2A, Iout below 0.7A DCM
Vin 1 Vin OUTPUT 2 1 L1 33uH 2 Vout
AP1512/A
5 C1 220uF/100V C2 3.3u ON/OFF SD GND 3 FB 4 D1 SR360
C7 3.3u
C3 1500uF/16V
Function Description
+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 a minimum. Feedback Senses the regulated output voltage to complete the feedback loop.
ON /OFF 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 40V) shuts the regulator down. If this shutdown feature is not needed, the SD pin can be wired to the ground pin or it can be left open, in either case the regulator will be in the ON condition.
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Thermal Considerations The AP1512/A is available in two packages, a 5-pin TO-220 and a 5-pin surface mount TO-263.
The TO-220 package needs a heat sink under most conditions. The size of the heatsink depends on the input voltage, the output voltage, the load current and the ambient temperature. The AP1512/A junction temperature rises above ambient temperature for a 2A load and different input and output voltages. The data for these curves was taken with the AP1512/A (TO-220 package) operating as a buck switching regulator in an ambient temperature of 25oC (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 board with large copper areas and/or airflow are recommended.
Rev.1.1 Oct. 14, 2005
AP1512/A
50KHz, 2A/3A PWM Buck DC/DC Converter Function Description (Continued)
The AP1512/A (TO-263 package) junction temperature rise 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, double sided 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. (Once 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, multilayer 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.
Marking Information
(1) TO263-5L
( Top View ) -Output Type: Blank: ADJ -33: 3.3V -50: 5.0V -12: 1.2V ID code Xth week: 01~52 Year: "01" = 2001 "02" = 2002
Logo Part Number: Blank: AP1512 A: AP1512A
1512X-XX YY WW X
~
(2) TO220-5L
( Top View ) -Output Type: Blank: ADJ -33: 3.3V -50: 5.0V -12: 1.2V ID code Xth week: 01~52 Year: "01" = 2001 "02" = 2002
Logo Part Number: Blank: AP1512 A: AP1512A
1512X-XX YY WW X
~
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Rev.1.1 Oct. 14, 2005
AP1512/A
50KHz, 2A/3A PWM Buck DC/DC Converter Package Information
(1) Package Type: TO220-5L
E ΦP H1 Q
A
F
L
D
e e1
b
C J1
Symbol
A b C D E e e1 F H1 J1 L Øp Q
Dimensions In Millimeters Min. Nom. Max. 4.45 4.07 4.82 0.76 0.89 1.02 0.36 0.50 0.64 14.22 14.86 15.50 9.78 10.16 10.54 1.57 1.71 1.85 6.68 6.81 6.93 1.14 1.27 1.40 5.46 6.16 6.86 2.29 2.74 3.18 13.21 13.97 14.73 3.68 3.81 3.94 2.54 2.73 2.92
Dimensions In Inches Min. Nom. Max.
0.160 0.030 0.014 0.560 0.385 0.062 0.263 0.045 0.215 0.090 0.520 0.145 0.100
0.175 0.035 0.020 0.585 0.400 0.067 0.268 0.050 0.243 0.108 0.550 0.150 0.107
0.190 0.040 0.025 0.610 0.415 0.073 0.273 0.055 0.270 0.125 0.580 0.155 0.115
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Rev.1.1 Oct. 14, 2005
AP1512/A
50KHz, 2A/3A PWM Buck DC/DC Converter Package Information (Continued)
(2) Package Type: TO263-5L
E L2 10.9
9.1
L
1.0 1.7 e B
Land Pattern Recommendation (Unit: mm)
2.5 C L1
Symbol
A B C C2 D E e L L1 L2
Dimensions In Millimeters Min. Nom. Max. 4.07 4.46 4.85 0.66 0.84 1.02 0.36 0.50 0.64 1.14 1.27 1.40 8.65 9.15 9.65 9.78 10.16 10.54 1.57 1.71 1.85 14.61 15.24 15.88 2.29 2.54 2.79 2.92
Dimensions In Inches Min. Nom. Max. 0.160 0.176 0.191 0.026 0.033 0.040 0.014 0.020 0.025 0.045 0.050 0.055 0.341 0.360 0.380 0.385 0.400 0.415 0.062 0.068 0.073 0.575 0.600 0.625 0.090 0.100 0.110 0.115
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C2
Rev.1.1 Oct. 14, 2005
A
15.7
D
AP1512/A
50KHz, 2A/3A PWM Buck DC/DC Converter Package Information (Continued)
(3) Package Type: TO220-5L(R) Mechanical drawing
E Q A F
H1
D d1 H2 H3
d2
J1 b e J2 J3
J3 J2 J1 E A
Symbol
A b D d1 d2 E e F H1 H2 H3 J1 J2 J3 Q
Dimensions In Millimeters Min. Nom. Max. 4.4 4.6 4.7 0.7 0.8 0.9 8.4 8.7 8.9 1.0 6.3 9.91 10.16 10.41 1.6 1.7 1.8 1.2 1.25 1.3 6.4 20.8 21.6 22.4 23.9 24.7 25.5 2.7 3.7 4.5 5.3 8.4 2.5 2.8 3.0
Dimensions In Inches Min. Nom. Max. 0.180 0.175 0.185 0.027 0.032 0.037 0.330 0.340 0.350 0.039 0.248 0.390 0.400 0.410 0.062 0.067 0.072 0.048 0.050 0.052 0.250 0.820 0.850 0.880 0.942 0.972 1.002 0.105 0.147 0.177 0.207 0.331 0.100 0.110 0.120
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Rev.1.1 Oct. 14, 2005