FSP3123 FOSLINK | Alldatasheet
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150KHZ 3A PWM BUCK DC/DC CONVERTER 2007-6-12 1/11 FSP3123 PIN CONFIGURATION ( 1 ) T O 2 2 0 - 5 L ( 2 ) T O 2 6 3 - 5 L ( T o p V i e w ) ( T o p V i e w ) (3) PDIP8L (Top View) Symbol TO220/TO263 PDIP Name Descriptions 1 1 Vin Operating Voltage Input 2 2 Output Switching Output 3 5~8 Gnd Ground 4 3 FB Output Voltage Feedback Control 5 4 SD ON/OFF Shutdown FEATURES z Output voltage: 3.3 V, 5.0V, 12V, and adjustable output version z Adjustable version output voltage range:1.23V to 18V±4% z 150KHz±15% fixed switching frequency z Voltage mode non-synchronous PWM control z Thermal-shutdown and current-limit protection z ON/OFF shutdown control input z Operating voltage can be up to 22V z Output load current: 3A z Low power standby mode z Built-in switching transistor on chip z TO220-5L ，TO263-5L and PDIP8L packages APPLICATIONS z Simple High-efficiency step-down regulator z On-card switching regulators z Positive to negative converter GENERAL DESCRIPTION The FSP3123 series are monolithic IC that design for a step-down DC/DC converter, and own the ability of driving a 3A 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. If current limit function occurred and V FB is down to 0.5V below, the switching frequency will be reduced. The FSP3123 series operates at a switching frequency of 150 KHz 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, a 5-lead TO-263 package or 8-lead PDIP. Metal Tab Gnd
1 VIN
2 OUTPUT
3 GND
150KHZ 3A PWM BUCK DC/DC CONVERTER 2007-6-12 2/11 FSP3123 ABSOLUTE MAXIMUM RATINGS Symbol Paramrter Rating Unit VCC Supply Voltage +24 V VSD ON/OFF Pin input Voltage -0.3 to +18 V VFB Feedback Pin Voltage -0.3 to +18 V VOUT Output Voltage to Ground -1 V PD Power Dissipation Internally Limited W TST Storage Temperature -65 to +150 ℃ TOP Operating Temperature -40 to +125 ℃ VOP Operating Voltage +4.5 to +22 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 Symbol Paramrter Conditions Min. Typ. Max. Unit -50 IB Feedback bias current VFB=1.3V(Adjustable version only) -10 -100 nA 127 150 173 FOSC Oscillator frequency 110 173 KHz FCSP Short Circuit Oscillator Frequency When Current Limit Occur and VFB ＜ 0.5V, T A=25°C 10 30 50 kHz 1.4 VSAT Saturation voltage IOUT=3A no outside circuit VFB=0V force driver on 1.5 V Max.Duty Cycle(ON) V FB=0V force driver on 100 DC Min.Duty Cycle(OFF) V FB=12V force driver off 0 % 3.6 6.9 ICL Current limit Peak current no outside circuit V FB=0V force driver on 3.4 7.5 A Output=0 no outside circuit VFB=12V force driver off -50 µA IL Output=-1 Output leakage current VIN=22V -30 mA IQ Quiescent Current V FB=12V force driver off 5 10 mA
200 ISTBY Standby Quiesient
ON/OFF Pin=5V VIN=22V 70 250 µA VIL Low(regultaor ON) 0.6 VIH ON/OFF pin logic input threshold voltage High(regultaor OFF) 2.0 1.3 V IH ON/OFF pin logic input current VLOGIC=2.5V(OFF) -15 IL ON/OFF pin input current VLOGIC=0.5V(ON) -5 µA TO220-5L 2.5 TO263-5L 3.5 θJC Thermal Resistence PDIP8L Junction to case 12 /W℃ TO220-5L 28 TO263-5L 23 θJA Thermal Resistence with Copper Area of Approximately 3 in2 PDIP8L Junction to ambient /W℃ Specifications with boldface type are for full operating temperature range, the other type are for TJ=25ºC.
150KHZ 3A PWM BUCK DC/DC CONVERTER 2007-6-12 3/11 FSP3123 ELECTRICAL CHARACTERISTICS (CONTINUED) Symbol Parameter Conditions Typ. Limit Unit VFB Output Feedback 5V≤VIN≤22V 0.2A≤ILOAD≤3A VOUT programmed for 1.23 1.193/1.18 1.267/1.28 V VMIN VMAX FSP3123-ADJ η Efficiency V IN =12V, I LOAD =3A 75 % VOUT Output voltage 5.5V≤VIN≤22V 0.2A≤ILOAD≤3A 3.3 3.168/3.135 3.432/3.465 V VMIN VMAX FSP3123-3.3V η Efficiency V IN =12V, I LOAD =3A 75 % VOUT Output voltage 8V≤VIN≤22V 0.2A≤ILOAD≤3A 5 4.8/4.75 5.2/5.25 V VMIN VMAX FSP3123-5.0V η Efficiency V IN =12V, I LOAD =3A 80 % VOUT Output voltage 15V≤VIN≤22V 0.2A≤ILOAD≤3A 12 11.52/11.4 12.48/12.6 V VMIN VMAX FSP3123-12V η Efficiency V IN =15V, I LOAD =3A 90 % Specifications with boldface type are for full operating temperature range, the other type are for TJ=25ºC. BLOCK DIAGRAM
150KHZ 3A PWM BUCK DC/DC CONVERTER 2007-6-12 4/11 FSP3123 FUNCTION DESCRIPTION Pin Function VIN This is the positive input supply for the IC switching regula tor. 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 (V IN – VSAT ) and approximately – 0.5V, with a duty cycle of approximately V OUT / V IN. To minimize coupling to sensitive circ uitry, 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 us ing 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 maxi mum of 18V) shuts the regula tor down. If this shutdown feature is not needed, the ON/OFF pin can be wired to the ground pin. Thermal Considerations The FSP3123 is available in thr ee packages, a 5-pin TO-220, 5-pin TO263 and a 8-pin PDIP Package. The TO-220 package needs a heat sink under most conditions. The size of the heat sink depends on the i nput voltage, the output voltage, the load current and the ambient temperature. The FSP3123 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 FSP3123 (TO-220 package) operating as a buck sw itching regulator in an ambient temperature of 25 oC (still air). These temperature rise numbers are all approx imate and there are many factors that can affect these temperatures. Higher ambient temperat ures require more heat sinking. The TO-263 surface mount package tab is desi gned 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 in 2, and ideally should have 2 or more square inches of 2 oz. Additional c opper area improves the thermal characteristics, but with copper areas greater than approximately 6 in 2, 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. The FSP3123 (TO-263 package) junction temperature ri se above ambient temperature with a 3A load for various input and output voltages. This data was taken wi th 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 fo r the approximate junction temperature for various conditions, but be aware that there are many factors that can affect the juncti on temperature. When load currents higher than 2A are used, double sided or mult ilayer 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 th is 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 ri se 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 ca n 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.
150KHZ 3A PWM BUCK DC/DC CONVERTER 2007-6-12 5/11 FSP3123 TYPICAL APPLICATION CIRCUITS (1) Fixed Output Circuit (2) Adjustable Output Circuit
150KHZ 3A PWM BUCK DC/DC CONVERTER 2007-6-12 6/11 FSP3123 TYPICAL PERFORMANCE CHARACTERISTICS
150KHZ 3A PWM BUCK DC/DC CONVERTER 2007-6-12 7/11 FSP3123 TYPICAL PERFORMANCE CHARACTERISTICS (CONTINUED)
150KHZ 3A PWM BUCK DC/DC CONVERTER 2007-6-12 8/11 FSP3123 ORDERING INFORMATION MARKING IN FORMATION 1) TO220-5L 2) TO263-5L (3) PDIP8L 3123-VV YYWWXX Logo Part Number: 3123-ADJ: ADJ 3123-33: 3.3V 3123-50: 5.0V 3123-12: 12V Internal Code Date Code: YY: Year (01=2001) WW: Nth week (01~52) FSP3123XXXX Package: T: TO220-5L K: TO263-5L N: PDIP8L Output Voltage: Blank: ADJ 33: 3.3V 50: 5.0V 12: 12V Packing: Blank: Tube or Bulk A: Tape & Reel Temperature Grade: E: -40~125℃ 3123-VV YYWWXX Logo Part Number: 3123-ADJ: ADJ 3123-33: 3.3V 3123-50: 5.0V 3123-12: 12V Internal Code Date Code: YY: Year (01=2001) WW: Nth week (01~52) Part number: 3123-ADJ: ADJ 3123-33: 3.3V 3123-50: 5.0V 3123-12: 12V Internal code Date code: YY: Year (01=2001) WW: Nth week (01~52) Logo 3123-VV YYWWXX
150KHZ 3A PWM BUCK DC/DC CONVERTER 2007-6-12 9/11 FSP3123 PACKAGE INFORMATION 1) TO220-5L A F C L D Q E e b P
150KHZ 3A PWM BUCK DC/DC CONVERTER 2007-6-12 10/11 FSP3123 2) TO263-5L L2 2.92 0.115 e B E D L C A 9.10 Land Pattern Recommendation (Unit: mm) 10.90 15.70 2.50 1.701.00
150KHZ 3A PWM BUCK DC/DC CONVERTER 2007-6-12 11/11 FSP3123 (3) PDIP8L A 5.33 0.210 A1 0.38 0.015 e 2.54 0.100 PIN #1INDENT 0.025 DEEP 0.006-0.008 Inch E-PIN 0.018inch D S e B A L 7°(4х) E eB C 15°(4х)