LM2576

LM2576 Series Description The MIK2576 series of regulators are monolithic integrated circuits that provide all the active functions for a step-down (buck) switching regulator, capable of driving 3A load with excellent line and load regulation. These devices are available in fixed output voltages of 3.3V, 5V, 12V, 15V, and an adjustable output versions. Requiring a minimum number of external components, these regulators are simple to use and include internal frequency compensation and a fixed-frequency oscillator. The MIK2576 series offers a high-efficiency replacement for popular three-terminal linear regulators. It substantially reduces the size of the heat sink, and in some cases no heat sink is required. A standard series of inductors optimized for use with the MIK2576 are available from several different manufacturers. This feature greatly simplifies the design of switch-mode power supplies. Other features include a guaranteed ± 4% tolerance on output voltage within specified input voltages and output load conditions, and ±10% on the oscillator frequency. External shutdown is included, featuring 50µA (typical) standby current. The output switch includes cycle-by-cycle current limiting, as well as thermal shutdown for full protection under fault conditions. Note: The MIK2576HV is not produced yet. Features • • • • • • • • • • • 3.3V, 5V, 12V, 15V, and adjustable output versions Adjustable version output voltage range 1.23V to 37V (57V for HV version) ±4% max over line and load conditions Guaranteed 3A output current Wide input voltage range, 40V up to 60V for HV version Requires onl y 4 external components 52 kHz fixed frequency oscillator TTL shutdown capability, low power standby mode High efficiency Uses readily available standard inductors Thermal shutdo wn and current limit protection Applications • • • • Simple high-efficiency step-down (buck) regulator Efficient pre-regulator for linear regulators On-card switching regulators Positive to negative converter (Buck -Boost) Typical application Figure 1.(Fixed Output Voltage Versions) 7V - 40V (60V for HV) UNREGULATED DC INPUT +VIN 1 MIK2576/ FEEDBACK MIK2576HV- 4 L1 OUTPUT 5.0 2 3 5 ON/OFF 100 H D1 + GND CIN + 1N5822 COUT 1000 F +5V REGULATED OUTPUT 3A LOAD BEIJING ESTEK ELECTRONICS CO.,LTD 1 LM2576 Series Block Diagram VIN UNREGULATED DC INPUT CIN FEEDBACK 1 INTERNAL REGULATOR ON/OFF ON/OFF 5 + 4 R2 FIXED GAIN ERROR AMP R1 1.0k + - COMPARATOR DRIVER 3 AMP SWITCH + 2 OUTPUT L1 VO UT + 3 1.23V 52kHZ BAND-GAP REFERENCE OSCILLATOR D1 CO UT RESET THERMAL SHUTDOWN CURRENT LIMIT GND L O A D 3.3V, R2 =1.7K 5V, R2 = 3.1K 12V, R2 = 8.84K 15V, R2 =11.3K For ADJ, Version R1 = Open, R2 =0Ω Ordering information Temperature Range -40° ≤ TA C ≤ 125° C Output Voltage, V 3.3 5.0 12 15 ADJ TO-263 Package Type MIK2576HVS-3.3 MIK2576HVS-5.0 MIK2576HVS-12 MIK2576HVS-15 MIK2576HVS-ADJ MIK2576S-3.3 MIK2576S-5.0 MIK2576S-12 MIK2576S-15 MIK2576S-ADJ MIK2576HVT-3.3 MIK2576HVT-5.0 MIK2576HVT-12 MIK2576HVT-15 MIK2576HVTADJ MIK2576T-3.3 MIK2576T-5.0 MIK2576T-12 MIK2576T-15 MIK2576T-ADJ TO-220 BEIJING ESTEK ELECTRONICS CO.,LTD 2 LM2576 Series Absolute Maximum Ratings (Note 1) Parameter Maximum Suppl y Voltage MIK2576 MIK2576HV ON/OFF Pin Input Voltage Output Voltage to Ground (Stead y State) Power Dissipation Storage Temperature Range Maximum Junction Temperature Minimum ESD Rating (C= 100pF, R = 1.5 k Ω ) Lead Temperature (Soldering, 10 Seconds) Maximu m 45 63 -0.3V ≤ V ≤ +VIN -1 Internally Limited -65 to +150 150 2 260 Units V V W ° C ° C kV ° C Operating Ratings Parameter Temperature Range MIK2576/ MIK2576HV Supply Voltage MIK2576 MIK2576HV Value -40 ≤ TJ ≤ +125 40 60 Units ° C V Electrical Characteristics MIK2576 -3.3, MIK2576HV -3.3 Specifications with standard type face are for T J = 25° and those with boldface type apply over full Operating Temperature Range. C, Symbol Parameter Conditions Typ SYSTEM P ARAMETERS (Note 3) Test Circuit Figure 2 VOUT Output Voltage VIN =12V, ILOAD =0.5A Circuit of Figure 2 6V ≤ VIN ≤ 40V, 0.5A ≤ ILOAD ≤ 3A Circuit of Figure 2 6V ≤ VIN ≤ 60V, 0.5A ≤ ILOAD ≤ 3A Circuit of Figure 2 VIN =12V, ILOAD =3A 3.3 3.234 3.366 3.3 3.168/3.135 3.432/3.465 3.3 3.168/3.135 3.450/3.482 75 V V(Min) V(Max) V V(Min) V(Max) V V(Min) V(Max) % MIK2576 -3.3 MIK2576HV -3.3 Limit (Note 2) Units (Limits) VOUT Output Voltage MIK2576 Output Voltage MIK2576HV Efficiency VOUT η Electrical Characteristics MIK2576 -5.0, MIK2576HV -5.0 Specifications with standard type face are for T J = 25° and those with boldface type apply over full Operating Temperature Range. C, Symbol Parameter Conditions Typ SYSTEM P ARAMETERS (Note 3) Test Circuit Figure 2 VOUT Output Voltage VIN =12V, ILOAD =0.5A Circuit of Figure 2 0.5A ≤ ILOAD ≤ 3A, 8V ≤ VIN ≤ 40V Circuit of Figure 2 0.5A ≤ ILOAD ≤ 3A, 8V ≤ VIN ≤ 60V Circuit of Figure 2 VIN =12V, ILOAD =3A 5.0 4.900 5.100 5.0 4.800/4.750 5.200/5.250 5.0 4.800/4.750 5.225/5.275 77 V V(Min) V(Max) V V(Min) V(Max) V V(Min) V(Max) % MIK2576 -5.0 MIK2576HV -5.0 Limit (Note 2) Units (Limits) VOUT Output Voltage MIK2576 Output Voltage MIK2576HV Efficiency VOUT η BEIJING ESTEK ELECTRONICS CO.,LTD 3 LM2576 Series Electrical Characteristics MIK2576 -12, MIK2576HV -12 Specifications with standard type face are for T J = 25° and those with boldface type apply over full Operating Temperature Range. C, Symbol Parameter Conditions MIK2576 -12 MIK2576HV -12 Typ SYSTEM P ARAMETERS (Note 3) Test Circuit Figure 2 VOUT Output Voltage VIN =25V, ILOAD =0.5A Circuit of Figure 2 0.5A ≤ ILOAD ≤ 3A, 15V ≤ VIN ≤ 40V Circuit of Figure 2 0.5A ≤ ILOAD ≤ 3A, 15V ≤ VIN ≤ 60V Circuit of Figure 2 VIN =15V, ILOAD =3A 12 11.76 12.24 12 11.52/11.40 12.48/12.60 12 11.52/11.40 12.54/12.66 88 V V(Min) V(Max) V V(Min) V(Max) V V(Min) V(Max) % Limit(Note 2) Units (Limits) VOUT Output Voltage MIK2576 Output Voltage MIK2576HV Efficiency VOUT η Electrical Characteristics MIK2576 -15, MIK2576HV -15 Specifications with standard type face are for T J = 25° and those with boldface type apply over full Operating Temperature Range. C, Symbol Parameter Conditions MIK2576 -15 MIK2576HV -15 Typ SYSTEM P ARAMETERS (Note 3) Test Circuit Figure 2 VOUT Output Voltage VIN =25, ILOAD =0.5A Circuit of Figure 2 0.5A ≤ ILOAD ≤ 3A, 18≤ VIN ≤ 40V Circuit of Figure 2 0.5A ≤ ILOAD ≤ 3A, 18 ≤ VIN ≤ 60V Circuit of Figure 2 VIN =18V, ILOAD =3A 15 14.70 15.30 15 14.40/14.25 15.60/15.75 15 14.40/14.25 15.68/15.83 88 V V(Min) V(Max) V V(Min) V(Max) V V(Min) V(Max) % Limit (Note 2) Units (Limits) VOUT Output Voltage MIK2576 Output Voltage MIK2576HV Efficiency VOUT η Electrical Characteristics MIK2576 -ADJ, MIK2576HV -ADJ Specifications with standard type face are for T J = 25° and those with boldface type apply over full Operating Temperature Range. C, Symbol Parameter Conditions MIK2576 -ADJ MIK2576HV -ADJ Typ SYSTEM P ARAMETERS (Note 3) Test Circuit Figure 2 VOUT Feedback Voltage VIN =12V, ILOAD =0.5A, VOUT =5V Circuit of Figure 2 0.5A ≤ ILOAD ≤ 3A , 8V ≤ VIN ≤ 40V VOUT =5V Circuit of Figure 2 0.5A ≤ ILOAD ≤ 3A, 8V ≤ VIN ≤ 60V, VOUT =5V Circuit of Figure 2 VIN =12V, ILOAD =3A, VOUT =5V 1.230 1.217 1.243 1.230 1.193/1.180 1.267/1.280 1.230 1.193/1.180 1.273/1.286 77 V V(Min) V(Max) V V(Min) V(Max) V V(Min) V(Max) % Limit(Note 2) Units (Limits) VOUT Feedback Voltage MIK2576 Feedback Voltage MIK2576HV Efficiency VOUT η BEIJING ESTEK ELECTRONICS CO.,LTD 4 LM2576 Series All Output Voltage Versions Electrical Characteristics Specifications with standard type face are for T J = 25° and those with boldface type apply over full Operating Temperature Range. C, Unless otherwise specified, V IN =12V for the 3.3V, 5V, and Adjustable version, V IN =25V for the 12V version, and V IN =30V for the 15V version, , ILOAD =500mA. Symbol Parameter Conditions MIK2576 -XX MIK2576HV -XX Typ DEVICE P ARAMETERS Ib fO Feedback Bias Current Oscillator Frequency VOUT =5V (Adjustable Version Onl y) (Note 8) 50 52 47/42 58/63 VSAT DC ICL Saturation Voltage Max Duty Cycle (ON) Current Limit IOUT =3A (Note 4) (Note 5) (Notes 4, 8) 1.4 1.8/2.0 98 93 5.8 4.2/3.5 6.9/7.5 IL Output Leakage Current Output = 0V IQ ISTBY Quiescent Current Standby Quiescent Current (Notes 6, 7): Output = -1V Output = -1V (Note 6) ___ ON/OFF Pin = 5V (OFF) 7.5 30 5 10 50 200 2 100/500 nA kHz kHz(Min) kHz(Max) V V(Max) % %(Min) A A(Min) A(Max) mA(Max) mA mA(Max) mA mA(Max) µA µA(Max) Limit (Note 2) Units (Limits) ___ ON/OFF CONTROL VIH __ ON/OFF Pin VIL Logic Input Level IIH __ ON/OFF Pin Input Current IIL VOUT = 0V VOUT = Nominal Output Voltage __ ON/OFF Pin = 5V (OFF) __ ON/OFF Pin = 0V (ON) 1.4 1.2 12 2.2/2.4 1.0/0.8 30 V(Min) V(Max) µA µA(Max) µA µA(Max) 0 10 Note Note Note Note Note Note Note Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is intended to be functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics. 2: All limits guaranteed at room temperature (standa rd type face) and at temperature extremes (bold type face). 3: External components such as the catch diode, inductor, input and output capacitors can affect switching regulator system performance. When the MIK2576/MIK2576HV is used as shown in the Figure 2 test circuit, system performance will be as shown in system parameters section of Electrical Characteristics. 4: Output pin sourcing current. No diode, inductor or capacitor connected to output. 5: Feedback pin removed from output and connected to 0V. 6: Feedback pin removed from output and connected to +12V for the Adjustable, 3.3V, and 5V, versions, and +25V for the 12V and 15V versions, to force the output transistor OFF. 7: VIN =40V (60V for high voltage version). 8: The oscillator frequency reduces to approximately 11 kHz in the event of an output short or an overload which causes the regulated output voltage to drop approximatel y 40% from the nominal output voltage. This self protections feature lowers the average power dissipation of the IC b y lowering the minimum dut y cycle from 5% do wn to approximatel y 2%. BEIJING ESTEK ELECTRONICS CO.,LTD 5 LM2576 Series Typical Performance Characteristics (Circuit of Figure 2) Normalized Output Voltage VIN =20V I L OA D = 500mA Normalized at TJ =25° C Line Regulation I L OA D = 500mA TJ =25° C 3.3V, 5V & ADJ 12V & 15V Dropout Voltage I L OA D = 3A L1 = 150 H I L OA D = 1A I L OA D = 200mA RIND = 0.1Ω JUNCTION TEMPERATURE (° ) C INPUT VOLTAGE (V) JUNCTION TEMPERATURE (° C) Standby Quiescent Current Quiescent Current Current Limit VIN = 25V VIN = 40V VOUT = 5V Measured at Ground Pin TJ =25° C ILOAD = 3A ILOAD = 200mA VON/ OFF = 5V VIN =12 V JUNCTIO N TEMPE RATURE (° C) INP UT VO LTAGE (V) JUNCTION TEMPE RATURE (° C) Switch Saturation Voltage Efficiency Oscilator Frequency Normalized at 25° C I L OA D = 3A -55° C 25° C 150° C 15V OUT 5V IL OA D = 3A TJ =25° C I L OA D = 200mA VIN = 40V IL OA D = 200mA SWITCH CURRENT (A) INPUT VOLTAGE (V) VIN = 12V JUNCTION TEMPERATURE (° C) Minimum Operating Voltage Quiescent Current vs Duty Cycle Adjustable Version Only Feedback Voltage vs Duty Cycle Adjustable Version Only Adjustable Version Only VIN = 7V VIN = 40V VOUT ≈ 1.23V I LOAD = 500mA I LOAD = 500mA VIN = 40V VIN = 7V I LOAD = 500mA JUNCTION TEMPERATURE (° C) DUTY CYCLE ( %) DUTY CYC LE ( %) BEIJING ESTEK ELECTRONICS CO.,LTD 6 LM2576 Series Maximum Power Dissipation (TO-263) Feedback Pin Current Adjus table Version Only θJ A = 32° /W C θA = 37° /W J C θA = 50° /W J C θA = 73° /W J C AM BIENT TEM PERATURE (° ) C JUNCTION TE MPERATURE (° ) C Switching Waveforms Response A Load Transient B Output Voltage Change C Load Current D 5 s/div 100 s/div VOUT =15V A: Output Pin Voltage, 50V/div B: Output Pin Current, 2A/div C: Inductor Current, 2A/div D: Output Ripple Voltage, 50mV/div, AC-Coupled Horizontal Time Base: 5µs/div BEIJING ESTEK ELECTRONICS CO.,LTD 7 LM2576 Series Test Circuit and La yout Guidelines As in any switching regulator, layout is very important. Rapidly switching currents associated with wiring inductance generate voltage transients which can cause problems. For minimal inductance and ground loops, the length of the leads indicated by heavy lines should be kept as short as possible. Single-point grounding (as indicated) or ground plane construction should be used for best results. When using the Adjustable version, physically locate the programming resistors near the regulator, to keep the sensitive feedback wiring short. Fixed Outpu t Voltage Versions FEEDBACK +VIN 1 VIN UNREGULATED DC INPUT (Figure 2a) MIK2576HVFIXED OUTPUT D 3 5 4 O UTPUT 2 L1 100 H D1 MBR360 VOUT L O A D + G 1 00 N F O N/OFF + COUT 1000 F CIN — 100µF, 75V, Aluminum Electrol ytic COUT — 1000µF, 25V, Aluminum Electrol ytic D1 — Schottky, MBR360 L1 — 100µH, Pulse Eng. PE -92108 R1 — 2k, 0.1% R2 — 6.12k, 0.1% Adjustable Output Voltage Version +VIN 1 7V -60V UNREGULATED DC INPUT (Figure 2b) VOUT 5.00V L O A D MIK2576HVADJ 3 5 FEEDBACK 4 L1 OUTPUT 2 100 H MBR360 R2 + 100 CIN F GND ON/OFF COUT + 1000 F R1 VOUT = R2 ) R V R 1 ( OUT− ) VREF 1 VREF 1 + R (2 where VREF = 1.23V, R1 between 1k and 5k Address : Postalcode:100039 Tel: 86-010-58895780 / 81 / 82 / 83 / 84 Http://www.estek.com.cn Email:sales@estek.com.cn 6A06--6A07 Rm 6A07,Changyin Office Building ,No.88,Yong Ding Road,Hai Dian District ,Beijing Fax : 010-58895793 REV No:01-060813 BEIJING ESTEK ELECTRONICS CO.,LTD 8