LM2576

TIGER ELECTRONIC CO.,LTD LM2576 Series Description The LM2576 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 LM2576 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 LM2576 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 LM2576HV is not produced yet. Features • • • • • • • • • • • Applications • • • • 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 shutdo wn capability, low power standby mode High efficiency Uses readil y available standard inductors Thermal shutdo wn and current limit protection 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 LM2576/ LM2576HV5.0 3 + GND CIN FEEDBACK 4 L1 OUTPUT 2 100 H 5 ON/OFF D1 1N5822 + COUT 1000 F +5V REGULATED OUTPUT 3A LOAD TIGER ELECTRONICS CO.,LTD 1 LM2576 Series Block Diagram VIN UNREGULATED DC INPUT CIN FEEDBACK 1 + INTERNAL REGULATOR ON/OFF 5 ON/OFF 4 R2 FIXED GAIN ERROR AMP R1 1.0k + - COMPARATOR DRIVER 3 AMP SWITCH OUTPUT 2 3 + - L1 VO UT + D1 CO UT 1.23V 52kHZ BAND-GAP REFERENCE OSCILLATOR 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°C ≤ TA ≤ 125°C Output Voltage, V 3.3 5.0 12 15 ADJ TO-263 Package Type LM2576SX-3.3 LM2576T-3.3 MIK2576T-3.3 LM2576SX-5.0 LM2576T-5.0 MIK2576T-5.0 LM2576SX-12 LM2576T-12 MIK2576T-12 LM2576SX-15 LM2576T-15 MIK2576T-15 LM2576SX-ADJ LM2576T-ADJ MIK2576T-ADJ TO-220 2 TIGER ELECTRONICS CO.,LTD LM2576 Series Absolute Maximum Ratings (Note 1) Parameter Maximum Suppl y Voltage LM2576 LM2576HV 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 LM2576/LM2576HV Supply Voltage Value -40 ≤ TJ ≤ +125 40 60 Units °C V LM2576 LM2576HV Electrical Characteristics LM2576 -3.3,LM2576HV-3.3 Specifications with standard type face are for T J = 25°C, and those with boldface type apply over full Operating Temperature Range. 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 3.168/3.135 3.432/3.465 3.168/3.135 3.450/3.482 V V(Min) V(Max) V V(Min) V(Max) V V(Min) V(Max) % LM2576-3.3 LM2576HV-3.3 Limit (Note 2) Units (Limits) VOUT Output Voltage LM2576 Output Voltage LM2576HV Efficiency 3.3 VOUT 3.3 η 75 Electrical Characteristics LM2576 -5.0, LM2576HV-5.0 Specifications with standard type face are for T J = 25°C, and those with boldface type apply over full Operating Temperature Range. 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 4.800/4.750 5.200/5.250 4.800/4.750 5.225/5.275 V V(Min) V(Max) V V(Min) V(Max) V V(Min) V(Max) % LM2576-5.0 LM2576HV-5.0 Limit (Note 2) Units (Limits) VOUT Output Voltage LM2576 Output Voltage LM2576HV Efficiency 5.0 VOUT 5.0 η 77 3 TIGER ELECTRONICS CO.,LTD LM2576 Series Electrical Characteristics LM2576 -12, LM2576HV-12 Specifications with standard type face are for T J = 25°C, and those with boldface type apply over full Operating Temperature Range. Symbol Parameter Conditions LM2576-12 LM2576HV-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 11.52/11.40 12.48/12.60 11.52/11.40 12.54/12.66 V V(Min) V(Max) V V(Min) V(Max) V V(Min) V(Max) % Limit(Note 2) Units (Limits) VOUT Output Voltage LM2576 Output Voltage LM2576HV Efficiency 12 VOUT 12 η 88 Electrical Characteristics LM2576 -15, LM2576HV-15 Specifications with standard type face are for T J = 25°C, and those with boldface type apply over full Operating Temperature Range. Symbol Parameter Conditions LM2576-15 LM2576HV-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 14.40/14.25 15.60/15.75 14.40/14.25 15.68/15.83 V V(Min) V(Max) V V(Min) V(Max) V V(Min) V(Max) % Limit (Note 2) Units (Limits) VOUT Output Voltage LM2576 Output Voltage LM2576HV Efficiency 15 VOUT 15 η 88 Electrical Characteristics LM2576-ADJ, LM2576HV-ADJ Specifications with standard type face are for T J = 25°C, and those with boldface type apply over full Operating Temperature Range. Symbol Parameter Conditions LM2576-ADJ LM2576HV-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 1.193/1.180 1.267/1.280 1.193/1.180 1.273/1.286 V V(Min) V(Max) V V(Min) V(Max) V V(Min) V(Max) % Limit(Note 2) Units (Limits) VOUT Feedback Voltage LM2576 Feedback Voltage LM2576HV Efficiency 1.230 VOUT 1.230 η 77 TIGER ELECTRONICS CO.,LTD 4 LM2576 Series All Output Voltage Versions Electrical Characteristics Specifications with standard type face are for T J = 25°C, and those with boldface type apply over full Operating Temperature Range. 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 LM2576-XX LM2576HV-XX Typ DEVICE P ARAMETERS Ib fO Feedback Bias Current Oscillator Frequency VOUT =5V (Adjustable Version Onl y) (Note 8) 50 52 100/500 47/42 58/63 1.8/2.0 93 4.2/3.5 6.9/7.5 2 30 10 200 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) VSAT DC ICL Saturation Voltage Max Duty Cycle (ON) Current Limit IOUT =3A (Note 4) (Note 5) (Notes 4, 8) 1.4 98 5.8 IL Output Leakage Current Output = 0V IQ ISTBY Quiescent Current Standby Quiescent Current (Notes 6, 7): Output = -1V Output = -1V 7.5 5 50 (Note 6) ___ ON/OFF Pin = 5V (OFF) ___ 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 0 2.2/2.4 1.0/0.8 30 10 V(Min) V(Max) µA µA(Max) µA µA(Max) 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 LM2576/LM2576HV is used as shown in the Figure 2 test circuit, system performance will be a 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 po wer dissipation of the IC b y lowering the minimum dut y cycle from 5% do wn to approximatel y 2%. TIGER 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 VON/ OFF = 5V VIN =12 V ILOAD = 200mA VOUT = 5V Measured at Ground Pin TJ =25°C ILOAD = 3A 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 VIN = 12V JUNCTION TEMPERATURE (°C) SWITCH CURRENT (A) INPUT VOLTAGE (V) 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 = 7V VIN = 40V I LOAD = 500mA DUTY CYCLE ( %) DUTY CYC LE ( %) JUNCTION TEMPERATURE (°C) TIGER ELECTRONICS CO.,LTD 6 LM2576 Series All Output Voltage Versions Electrical Characteristics Specifications with standard type face are for T J = 25°C, and those with boldface type apply over full Operating Temperature Range. 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 LM2576-XX LM2576HV-XX Typ DEVICE P ARAMETERS Ib fO Feedback Bias Current Oscillator Frequency VOUT =5V (Adjustable Version Onl y) (Note 8) 50 52 100/500 47/42 58/63 1.8/2.0 93 4.2/3.5 6.9/7.5 2 30 10 200 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) VSAT DC ICL Saturation Voltage Max Duty Cycle (ON) Current Limit IOUT =3A (Note 4) (Note 5) (Notes 4, 8) 1.4 98 5.8 IL Output Leakage Current Output = 0V IQ ISTBY Quiescent Current Standby Quiescent Current (Notes 6, 7): Output = -1V Output = -1V 7.5 5 50 (Note 6) ___ ON/OFF Pin = 5V (OFF) ___ 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 0 2.2/2.4 1.0/0.8 30 10 V(Min) V(Max) µA µA(Max) µA µA(Max) 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 LM2576/ LM2576HV is used as shown in the Figure 2 test circuit, system performance will be a 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 po wer dissipation of the IC b y lowering the minimum dut y cycle from 5% do wn to approximatel y 2%. TIGER ELECTRONICS CO.,LTD 5 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 Output Voltage Versions +VIN 1 VIN UNREGULATED DC INPUT (Figure 2a) LM2576HVFIXED OUTPUT D 3 5 FEEDBACK 4 O UTPUT 2 L1 100 H D1 MBR360 VOUT + G 100 N F O N/OFF + COUT 1000 F L O A D 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 R2 L O A D LM2576HVADJ 3 5 FEEDBACK 4 L1 OUTPUT 2 100 H MBR360 COUT + 100 CIN F GND ON/OFF + 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 REV No:01-060813 TIGER ELECTRONICS CO.,LTD 8