LM2575GT-ADJ

1A, 52kHz, Step-Down Switching Regulator LM2575 FEATURES 3.3V, 5.0V, 12V, 15V, and Adjustable Output Versions TO-220 PKG Adjustable Version Output Voltage Range, 1.23 to 37V +/- 4% AG10 Maximum Over Line and Load Conditions Guaranteed 1A Output Current Wide Input Voltage Range Requires Only 4 External Components 1 52kHz Fixed Frequency Internal Oscillator 5 TTL Shutdown Capability, Low Power Standby Mode TO-220V PKG High Efficiency Uses Readily Available Standard Inductors 1 Thermal Shutdown and Current Limit Protection Moisture Sensitivity Level 3 5 Applications Simple High-Efficiency Step-Down(Buck) Regulator TO-263 PKG Efficient Pre-Regulator for Linear Regulators On-Card Switching Regulators Positive to Negative Converter(Buck-Boost) 1 Negative Step-Up Converters 5 Power Supply for Battery Chargers 1. Vin 2. Output 3. Ground 4. Feedback 5. On/Off DESCRIPTION ORDERING INFORMATION The LM2575 series of regulators are monolithic integrated Device Marking Package circuits ideally suited for easy and convenient design of a LM2575T-X.X LM2575T-X.X TO-220 step-down switching regualtor(buck converter). LM2575TV-X.X LM2575T-X.X TO-220V All circuits of this series are capable of driving a 1A load LM2575R LM2575R-X.X TO-263 with excellent line and load regulation. These devices are available in fixed output voltages of 3.3V, 5.0V,12V, 15V, and an adjustable output version. These regulatiors were designed to minimize the number of externalcomponents to simplify the power supply design. Standard series of inductors optimized for use with the LM2575 are offered by several different inductor manufacturers. Since the LM2575 converter is a switch-mode power supply, its efficiency is significantly higher in comparison with popular three-terminal limear reguators, especially with higher input voltages. In many cases, the power dissipated is so low that no heatsink is required or its size could be reduced dramatically. A standard series of inductors optimized for use with the LM2575 are available from several different manufacturers. This feature greatly simplifies the design of switch-mode power supplies. The LM2575 features include a guaranteed +/- 4% tolerance on output voltage within specified input voltages and output load conditions, and +/-10% on the oscillator frequency (+/- 2% over 0℃ to 125 ℃). External shutdown is included, featuring 80 ㎂(typical) standby current. The output switch includes cycle-bycycle current limiting, as well as thermal shutdown for full protection under fault conditions. HTC 2008 - Ver. 1.0 −1− 1A, 52kHz, Step-Down Switching Regulator LM2575 Typical Application (Fixed Output Voltage Versions) LM2575 1A Load Figure 1. Block Diagram and Typical Application ABSOLUTE MAXIMUM RATINGS (Absolute Maximum Ratings indicate limits beyond which damage to the device may occur) Rating Maximum Supply Voltage On/Off Pin Input Voltage Output Voltage to Ground (Steady-State) Power Dissipation TO-220 5Lead Thermal Resistance, Juntion to Ambient Thermal Resistance, Juntion to Case TO-263 5Lead Thermal Resistance, Juntion to Ambient Thermal Resistance, Juntion to Case Storage Temperature Range Minimum ESD Rating(Human Body Model : C=100 pF, R=1.5㏀) Lead Temperature (Soldering,10seconds) Maximum Junction Temperature Symbol Vin - Value 45 -0.3V ≤ V ≤ +Vin - 1.0 Unit V V V PD PθJA PθJC PD PθJA PθJC Tstg Internally Limited 65 5.0 Internally Limited 70 5.0 -60 to +150 W ℃/W ℃/W W ℃/W ℃/W ℃ - 2.0 kV TJ 260 150 ℃ ℃ HTC −2− 1A, 52kHz, Step-Down Switching Regulator LM2575 OPERATING RATINGS(Operating Ratings indicate conditions for which the device is intended to be functional, but do not guarantee specific performance limits. For guaranteed specifications, see the Electrical Characteristics.) Rating Operating Junction Temperature Range Supply Voltage Symbol TJ Value -40 to +125 40 Vin Unit ℃ V ELECTRICAL CHARACTERISTICS / SYSTEM PARAMETERS ([Note 1] Test Circuit Figure 15) (Unless otherwise specified, Vin = 12 V for the 3.3 V, 5.0 V, and Adjustable version, Vin = 25 V for the 12 V version, and Vin = 30 V for the 15 V version. ILoad = 500 mA. For typical values TJ = 25°C, for min/max values TJ is the operating junction temperature range that applies [Note 2], unless otherwise noted.) Characteristics Symbol Min TYP Max Unit Vout 3.234 3.3 3.366 V Vout 3.3 75 3.432 3.465 - V η 3.168 3.135 - % Vout 4.9 5.0 5.1 V Vout 5.0 77 5.2 5.25 - V η 4.8 4.75 - % Vout 11.76 12 12.24 V Vout 12 88 12.48 12.6 - V η 11.52 11.4 - % Vout 1.217 1.23 1.243 V Vout 1.193 1.18 - 1.23 77 1.267 1.28 - V LM2575-3.3V ([Note 1] Test Circuit Figure 2) Output Voltage (Vin = 12V, ILOAD=0.5A, TJ=25℃) Output Voltage (6.0V≤Vin≤40V, 0.5A≤ILOAD≤1A TJ=25℃ TJ= -40℃ ~ +125℃ Efficiency (Vin=12V, ILOAD=1A) LM2575-5.0V ([Note 1] Test Circuit Figure 2) Output Voltage (Vin = 12V, ILOAD=0.5A, TJ=25℃) Output Voltage (8.0V≤Vin≤40V, 0.5A≤ILOAD≤1A TJ=25℃ TJ= -40℃ ~ +125℃ Efficiency (Vin=12V, ILOAD=1A) LM2575-12V ([Note 1] Test Circuit Figure 2) Output Voltage (Vin = 25V, ILOAD=0.5A, TJ=25℃) Output Voltage (15V≤Vin≤40V, 0.5A≤ILOAD≤1A TJ=25℃ TJ= -40℃ ~ +125℃ Efficiency (Vin=12V, ILOAD=1A) LM2575-ADJ ([Note 1] Test Circuit Figure 2) Feedback Voltage (Vin=12V, ILOAD=0.5A, TJ=25℃) Feedback Voltage(8.0V≤Vin≤40V, 0.5A≤ILOAD≤1A, Vout=5.0V) TJ=25℃ TJ= -40℃ ~ +125℃ η Efficiency (Vin=12V, ILOAD=1A, Vout=5.0V) % 1. External components such as the catch diode, inductor, input and output capacitors can affect switching regulator system performance. When the LM2575 is used as shown in the Figure 15 test circuit, system performance will be as shown in system parameters section . 2. Tested junction temperature range for the LM2575: Tlow = –40°C Thigh = +125°C HTC −3− 1A, 52kHz, Step-Down Switching Regulator LM2575 ELECTRICAL CHARACTERISTICS / Device Parameters (Unless otherwise specified, Vin = 12 V for the 3.3 V, 5.0 V, and Adjustable version, Vin = 25 V for the 12 V version, and Vin = 30 V for the 15 V version. ILoad = 500 mA. For typical values TJ = 25°C, for min/max values TJ is the operating junction temperature range that applies [Note 2], unless otherwise noted.) Characteristics All Output Voltage Versions Symbol Min TYP Max Unit Ib - 25 - 100 200 nA 47 42 52 - 58 63 94 1.2 98 1.4 1.7 - ICL 4.2 3.5 5.8 - 6.9 7.5 A IL - 0.8 6 50 30 mA IQ - 5 - 9 11 mA ISTBY - 80 - 200 400 ㎂ 2.2 2.4 1.4 - - VIL - 1.2 - 1 0.8 V IIH IIL - 15 0 30 5.0 ㎂ Feedback Bias Current (Vout=5.0V [Adjustable Version Only]) TJ=25℃ TJ= -40 to +125℃ Oscillator Frequency [Note 3] TJ=25℃ TJ= 0 to +125℃ TJ= -40 to +125℃ Saturation Voltage (Iout=1A [note 4]) TJ=25℃ TJ= -40 to +125℃ Max Duty Cycle ("0") [Note 5] Current Limit (Peak Current [Note 3 and 4]) TJ=25℃ TJ= -40 to +125℃ Output Leakage Current [Note 6 and 7], TJ=25℃ Output = 0V Output = -1.0V Quiescent Current [Note 6] TJ=25℃ TJ= -40 to +125℃ Standby Quiescent Current (ON/OFF Pin = 5.0V ("off")) TJ=25℃ TJ= -40 to +125℃ ON/OFF Pin Logic Input Level (Test circuit Figure 15) Vout=0V TJ=25℃ TJ= -40 to +125℃ Vout=Nominal Output Voltage TJ=25℃ TJ= -40 to +125℃ ON/OFF Pin Input Current (Test Circuit Figure 15) ON/OFF Pin = 5.0V (Regulator OFF), TJ=25℃ ON/OFF Pin = 0V (Regulator ON), TJ=25℃ Fosc Vsat DC VIH kHz V % V 3. The oscillator frequency reduces to approximately 18 kHz in the event of an output short or an overload which causes the regulated output voltage to drop approximately 40% from the nominal output voltage. This self protection feature lowers the average dissipation of the IC by lowering the minimum duty cycle from 5% down to approximately 2%. 4. Output (Pin 2) sourcing current. No diode, inductor or capacitor connected to output pin. 5. Feedback (Pin 4) removed from output and connected to 0 V. 6. Feedback (Pin 4) removed from output and connected to +12 V for the Adjustable, 3.3 V, and 5.0V ersions, and +25 V for the 12 V and15 V versions, to force the output transistor “off”. 7. Vin = 40 V. −4− HTC 1A, 52kHz, Step-Down Switching Regulator LM2575 TYPICAL PERFORMANCE CHARACTERISTICS (Circuit of Figure 15) HTC −5− 1A, 52kHz, Step-Down Switching Regulator LM2575 TYPICAL PERFORMANCE CHARACTERISTICS (Circuit of Figure 15) HTC −6− 1A, 52kHz, Step-Down Switching Regulator LM2575 LM2575 LM2575 HTC −7− 1A, 52kHz, Step-Down Switching Regulator LM2575 PIN FUNCTION DESCRIPTION Symbol 1 2 3 4 5 Vin Description This pin is the positive input supply for the LM2575 step–down switching regulator.In order to minimize voltage transients and to supply the switching currents needed by the regulator, a suitable input bypass capacitor must be present .(Cin in Figure 1). Output This is the emitter of the internal switch. The saturation voltage Vsat of this output switch is typically 1.5 V. It should be kept in mind that the PCB area connected to this pin should be kept to a minimum in order to minimize coupling to sensitive circuitry. Circuit ground pin. See the information about the printed circuit board layout. Gnd Feedback This pin senses regulated output voltage to complete the feedback loop. The signal is divided by the internal resistor divider network R2, R1 and applied to the non–inverting input of the internal error amplifier. In the Adjustable version of the LM2575 switching regulator this pin is the direct input of the error amplifier and the resistor network R2, R1 is connected externally to allow programming of the output voltage. ON/OFF It allows the switching regulator circuit to be shut down using logic level signals, thus dropping the total input supply current to approximately 80 mA. The threshold voltage is typically 1.4 V. Applying a voltage above this value (up to +Vin) shuts the regulator off. If the voltage applied to this pin is lower than 1.4V or if this pin is left open, the regulator will be in the "on" condition HTC −8− 1A, 52kHz, Step-Down Switching Regulator LM2575 LM2575-5.0 HTC −9− 1A, 52kHz, Step-Down Switching Regulator LM2575 LM2575 LM2575-ADJ HTC − 10 − 1A, 52kHz, Step-Down Switching Regulator LM2575 LM2575-ADJ HTC − 11 − LM2575 1A, 52kHz, Step-Down Switching Regulator LM2575-3.3V LM2575-5.0V LM2575-12V LM2575-15V LM2575-ADJ HTC − 12 − 1A, 52kHz, Step-Down Switching Regulator LM2575 HTC − 13 −