TL2575HV-05QKTTRQ1

TL2575HV-33-Q1 TL2575HV-05-Q1 www.ti.com SLVSAH9 – SEPTEMBER 2010 1-A SIMPLE STEP-DOWN SWITCHING VOLTAGE REGULATORS Check for Samples: TL2575HV-33-Q1, TL2575HV-05-Q1 FEATURES 1 • Fixed 3.3-V and 5-V Options With ±5% Regulation (Max) Over Line, Load, and Temperature Conditions Specified 1-A Output Current Wide Input Voltage Range…4.75 V to 60 V Require Only Four External Components (Fixed Versions) and Use Readily Available Standard Inductors 52-kHz (Typ) Fixed-Frequency Internal Oscillator TTL Shutdown Capability With 50-mA (Typ) Standby Current High Efficiency…as High as 88% (Typ) Thermal Shutdown and Current-Limit Protection With Cycle-by-Cycle Current Limiting • • • • • • • APPLICATIONS • • • • Simple High-Efficiency Step-Down (Buck) Regulators Pre-Regulators for Linear Regulators On-Card Switching Regulators Positive-to-Negative Converters (Buck-Boost) DESCRIPTION/ORDERING INFORMATION The TL2575HV-33 and TL2575HV-05 greatly simplify the design of switching power supplies by conveniently providing all the active functions needed for a step-down (buck) switching regulator in an integrated circuit. Accepting a wide input voltage range of up to 60 V and available in fixed output voltages of 3.3 V or 5 V, the TL2575HV-33 and TL2575HV-05 have an integrated switch capable of delivering 1 A of load current, with excellent line and load regulation. The device also offers internal frequency compensation, a fixed-frequency oscillator, cycle-by-cycle current limiting, and thermal shutdown. In addition, a manual shutdown is available via an external ON/OFF pin. The TL2575HV-33 and TL2575HV-05 represent superior alternatives to popular three-terminal linear regulators. Due to their high efficiency, the devices significantly reduce the size of the heat sink and, in many cases, no heat sink is required. Optimized for use with standard series of inductors available from several different manufacturers, the TL2575HV-33 and TL2575HV-05 greatly simplify the design of switch-mode power supplies by requiring a minimal addition of only four to six external components for operation. The TL2575HV-33 and TL2575HV-05 are characterized for operation over the virtual junction temperature range of –40°C to 125°C. ORDERING INFORMATION (1) TJ –40°C to 125°C (1) (2) VO (NOM) PACKAGE (2) ORDERABLE PART NUMBER TOP-SIDE MARKING 3.3 V TO-263 – KTT Reel of 500 TL2575HV-33QKTTRQ1 2BHV-33Q 5V TO-263 – KTT Reel of 500 TL2575HV-05QKTTRQ1 2BHV-05Q For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI web site at www.ti.com. Package drawings, standard packing quantities, thermal data, symbolization, and PCB design guidelines are available at www.ti.com/sc/package. 1 Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2010, Texas Instruments Incorporated TL2575HV-33-Q1 TL2575HV-05-Q1 SLVSAH9 – SEPTEMBER 2010 www.ti.com FUNCTIONAL BLOCK DIAGRAM 2 Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated Product Folder Link(s): TL2575HV-33-Q1 TL2575HV-05-Q1 TL2575HV-33-Q1 TL2575HV-05-Q1 www.ti.com SLVSAH9 – SEPTEMBER 2010 ABSOLUTE MAXIMUM RATINGS (1) over operating free-air temperature range (unless otherwise noted) MIN VIN Supply voltage MAX TL2575HV 60 TL2575 42 ON/OFF input voltage range –0.3 Maximum junction temperature Tstg Storage temperature range (1) V VIN Output voltage to GND (steady state) TJ UNIT –65 V –1 V 150 °C 150 °C Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under recommended operating conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. PACKAGE THERMAL DATA (1) (1) (2) PACKAGE BOARD qJA qJC TO-263 (KTT) High K, JESD 51-5 26.5°C/W 31.8°C/W qJP (2) 0.38°C/W Maximum power dissipation is a function of TJ(max), qJA, and TA. The maximum allowable power dissipation at any allowable ambient temperature is PD = (TJ(max) – TA)/qJA. Operating at the absolute maximum TJ of 150°C can affect reliability. For packages with exposed thermal pads, such as QFN, PowerPAD™, or PowerFLEX™, qJP is defined as the thermal resistance between the die junction and the bottom of the exposed pad. RECOMMENDED OPERATING CONDITIONS MIN MAX VIN Supply voltage 4.75 60 V TJ Operating virtual junction temperature –40 125 °C Copyright © 2010, Texas Instruments Incorporated UNIT Submit Documentation Feedback Product Folder Link(s): TL2575HV-33-Q1 TL2575HV-05-Q1 3 TL2575HV-33-Q1 TL2575HV-05-Q1 SLVSAH9 – SEPTEMBER 2010 www.ti.com ELECTRICAL CHARACTERISTICS ILOAD = 200 mA, VIN = 12 V for 3.3-V, 5-V (unless otherwise noted) (see Figure 1) PARAMETER TEST CONDITIONS TL2575HV-33 VOUT Output voltage 3.234 3.3 3.366 25°C 3.168 3.3 3.450 Full range 3.135 8 V ≤ VIN ≤ 60 V, 0.2 A ≤ ILOAD ≤ 1 A TL2575HV-05 VIN = 12 V, ILOAD = 1 A fo Oscillator frequency (1) VSAT Saturation voltage IOUT = 1 A (2) Maximum duty cycle (3) ICL Switch peak current (1) IL Output leakage current IQ Quiescent current (4) ISTBY Standby quiescent current (2) VIN = 60 (4), Output = 0 V VIN = 60 (4), Output = –1 V OFF (ON/OFF = 5 V) VIH ON/OFF high-level logic input voltage VIL ON/OFF low-level logic input voltage ON (VOUT = nominal voltage) IIH ON/OFF high-level input current OFF (ON/OFF = 5 V) IIL ON/OFF low-level input current ON (ON/OFF = 0 V) (1) (2) (3) (4) 4 MAX 25°C VIN = 12 V, ILOAD = 1 A Efficiency TYP 4.75 V ≤ VIN ≤ 60 V, 0.2 A ≤ ILOAD ≤ 1 A TL2575HV-33 h MIN VIN = 12 V, ILOAD = 0.2 A VIN = 12 V, ILOAD = 0.2 A TL2575HV-05 TL2575HV TJ OFF (VOUT = 0 V) 25°C UNIT 3.482 4.9 5 5.1 25°C 4.8 5 5.225 Full range 4.75 V 5.275 75 25°C % 77 25°C 47 Full range 42 25°C 52 58 63 0.9 Full range kHz 1.2 V 1.4 25°C 93 98 25°C 1.7 2.8 Full range 1.3 % 3.6 2 25°C A 4 7.5 30 mA 25°C 5 10 mA 25°C 50 200 mA 25°C 2.2 Full range 2.4 25°C 1.4 1.2 Full range V 1 V 0.8 25°C 12 30 mA 0 10 mA In the event of an output short or an overload condition, self-protection features lower the oscillator frequency to ∼18 kHz and the minimum duty cycle from 5% to ∼2%. The resulting output voltage drops to ∼40% of its nominal value, causing the average power dissipated by the IC to lower. Output is not connected to diode, inductor, or capacitor. Output is sourcing current. FEEDBACK is disconnected from output and connected to 0 V. To force the output transistor off, FEEDBACK is disconnected from output and connected to 3.3 V and 5 V. Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated Product Folder Link(s): TL2575HV-33-Q1 TL2575HV-05-Q1 TL2575HV-33-Q1 TL2575HV-05-Q1 www.ti.com SLVSAH9 – SEPTEMBER 2010 TEST CIRCUITS Figure 1. Test Circuits and Layout Guidelines Copyright © 2010, Texas Instruments Incorporated Submit Documentation Feedback Product Folder Link(s): TL2575HV-33-Q1 TL2575HV-05-Q1 5 TL2575HV-33-Q1 TL2575HV-05-Q1 SLVSAH9 – SEPTEMBER 2010 www.ti.com TYPICAL CHARACTERISTICS 1 Output Voltage Change – % 0.6 TJ = 25°C 1 TJ = 25°C 0.4 0.2 0 -0.2 -0.4 -0.6 0.8 0.6 0.4 0.2 0 -0.2 -0.4 -0.8 -1 -50 ILOAD = 200 mA 1.2 ILOAD = 200 mA Output Voltage Change – % 0.8 1.4 VIN = 20 V -0.6 -25 0 25 50 75 100 125 0 150 10 20 Figure 2. Normalized Output Voltage 50 60 Figure 3. Line Regulation 2 3 DVOUT = 5% RIND = 0.2 W 2.5 1.5 ILOAD = 1 A 1.25 1 0.75 ILOAD = 200 mA 0.5 0.25 IO – Output Current – A Input-Output Differential – V 40 VIN – Input Voltage – V TA – Temperature – °C 1.75 30 2 1.5 1 0.5 0 -40 -25 -10 5 20 35 50 65 80 95 110 125 TJ – Junction Temperature – °C 0 -50 -25 0 25 50 75 100 125 150 TJ – Junction Temperature – °C Figure 4. Dropout Voltage 6 Submit Documentation Feedback Figure 5. Current Limit Copyright © 2010, Texas Instruments Incorporated Product Folder Link(s): TL2575HV-33-Q1 TL2575HV-05-Q1 TL2575HV-33-Q1 TL2575HV-05-Q1 www.ti.com SLVSAH9 – SEPTEMBER 2010 TYPICAL CHARACTERISTICS (continued) 500 VON/OFF = 5 V 18 VOUT = 5 V 16 TJ = 25°C Measured at GND pin ISTBY – Standby Quiescent Current – µA IQ – Quiescent Current – mA 20 14 12 10 ILOAD = 1 A 8 6 ILOAD = 0.2 A 4 2 0 0 10 20 30 40 50 450 VIN = 40 V 400 350 300 250 200 150 100 VIN = 12 V 50 0 -50 60 VIN – Input Voltage – V -25 0 25 50 75 100 125 150 TJ – Junction Temperature – °C Figure 6. Quiescent Current Figure 7. Standby Quiescent Current 1.2 10 Normalized at TJ = 25°C 1.1 6 VIN = 12 V VSAT – Saturation Voltage – V f NORM – Normalized Frequency – % 8 4 2 0 VIN = 40 V -2 -4 -6 -8 -10 -50 1 TJ = –40°C 0.9 0.8 TJ = 25°C 0.7 0.6 TJ = 125°C 0.5 -25 0 25 50 75 100 TJ – Junction Temperature – °C Figure 8. Oscillator Frequency Copyright © 2010, Texas Instruments Incorporated 125 150 0.4 0 0.2 0.4 0.6 0.8 1 ISW – Switch Current – A Figure 9. Switch Saturation Voltage Submit Documentation Feedback Product Folder Link(s): TL2575HV-33-Q1 TL2575HV-05-Q1 7 TL2575HV-33-Q1 TL2575HV-05-Q1 SLVSAH9 – SEPTEMBER 2010 www.ti.com TYPICAL CHARACTERISTICS (continued) VOUT = 5 V A B C { 0V { 0A { 0A { D 4 µs/Div D. Output ripple voltage, 20 mV/Div Figure 10. Switching Waveforms 8 Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated Product Folder Link(s): TL2575HV-33-Q1 TL2575HV-05-Q1 TL2575HV-33-Q1 TL2575HV-05-Q1 www.ti.com SLVSAH9 – SEPTEMBER 2010 TYPICAL CHARACTERISTICS (continued) 0.2 ILOAD – Load Current – A 0.15 0.1 0.05 0 -0.05 -0.1 -0.15 -0.2 -0.1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0.5 0.6 0.7 0.8 0.9 t – Time – ms 1.6 1.4 ILOAD – Load Current – A 1.2 1 0.8 0.6 0.4 0.2 0 -0.1 0 0.1 0.2 0.3 0.4 t – Time – ms Figure 11. Load Transient Response Copyright © 2010, Texas Instruments Incorporated Submit Documentation Feedback Product Folder Link(s): TL2575HV-33-Q1 TL2575HV-05-Q1 9 TL2575HV-33-Q1 TL2575HV-05-Q1 SLVSAH9 – SEPTEMBER 2010 www.ti.com APPLICATION INFORMATION Input Capacitor (CIN) For stability concerns, an input bypass capacitor (electrolytic, CIN ≥ 47 mF) needs to be located as close as possible to the regulator. For operating temperatures below –25°C, CIN may need to be larger in value. In addition, since most electrolytic capacitors have decreasing capacitances and increasing ESR as temperature drops, adding a ceramic or solid tantalum capacitor in parallel increases the stability in cold temperatures. To extend the capacitor operating lifetime, the capacitor RMS ripple current rating should be: IC,RMS > 1.2(ton/T)ILOAD where ton/T = VOUT/VIN {buck regulator} and ton/T = |VOUT|/(|VOUT| + VIN) {buck-boost regulator} Output Capacitor (COUT) For both loop stability and filtering of ripple voltage, an output capacitor also is required, again in close proximity to the regulator. For best performance, low-ESR aluminum electrolytics are recommended, although standard aluminum electrolytics may be adequate for some applications. Based on the following equation: Output ripple voltage = (ESR of COUT) × (inductor ripple current) Output ripple of 50 mV to 150 mV typically can be achieved with capacitor values of 220 mF to 680 mF. Larger COUT can reduce the ripple 20 mV to 50 mV peak to peak. To improve further on output ripple, paralleling of standard electrolytic capacitors may be used. Alternatively, higher-grade capacitors such as high frequency, low inductance, or low ESR can be used. The following should be taken into account when selecting COUT: • At cold temperatures, the ESR of the electrolytic capacitors can rise dramatically (typically 3× nominal value at –25°C). Because solid tantalum capacitors have significantly better ESR specifications at cold temperatures, they should be used at operating temperature lower than –25°C. As an alternative, tantalums also can be paralleled to aluminum electrolytics and should contribute 10% to 20% to the total capacitance. • Low ESR for COUT is desirable for low output ripple. However, the ESR should be greater than 0.05 Ω to avoid the possibility of regulator instability. Hence, a sole tantalum capacitor used for COUT is most susceptible to this occurrence. • The capacitor’s ripple current rating of 52 kHz should be at least 50% higher than the peak-to-peak inductor ripple current. Catch Diode As with other external components, the catch diode should be placed close to the output to minimize unwanted noise. Schottky diodes have fast switching speeds and low forward voltage drops and, thus, offer the best performance, especially for switching regulators with low output voltages (VOUT < 5 V). If a high-efficiency, fast-recovery, or ultra-fast-recovery diode is used in place of a Schottky, it should have a soft recovery (versus abrupt turn-off characteristics) to avoid the chance of causing instability and EMI. Standard 50-/60-Hz diodes, such as the 1N4001 or 1N5400 series, are not suitable. 10 Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated Product Folder Link(s): TL2575HV-33-Q1 TL2575HV-05-Q1 TL2575HV-33-Q1 TL2575HV-05-Q1 www.ti.com SLVSAH9 – SEPTEMBER 2010 Inductor Proper inductor selection is key to the performance-switching power-supply designs. One important factor to consider is whether the regulator is used in continuous mode (inductor current flows continuously and never drops to zero) or in discontinuous mode (inductor current goes to zero during the normal switching cycle). Each mode has distinctively different operating characteristics and, therefore, can affect the regulator performance and requirements. In many applications, the continuous mode is the preferred mode of operation, since it offers greater output power with lower peak currents, and also can result in lower output ripple voltage. The advantages of continuous mode of operation come at the expense of a larger inductor required to keep inductor current continuous, especially at low output currents and/or high input voltages. The TL2575 and TL2575HV can operate in either continuous or discontinuous mode. With heavy load currents, the inductor current flows continuously and the regulator operates in continuous mode. Under light load, the inductor fully discharges and the regulator is forced into the discontinuous mode of operation. For light loads (approximately 200 mA or less), this discontinuous mode of operation is perfectly acceptable and may be desirable solely to keep the inductor value and size small. Any buck regulator eventually operates in discontinuous mode when the load current is light enough. The type of inductor chosen can have advantages and disadvantages. If high performance/quality is a concern, then more-expensive toroid core inductors are the best choice, as the magnetic flux is contained completely within the core, resulting in less EMI and noise in nearby sensitive circuits. Inexpensive bobbin core inductors, however, generate more EMI as the open core does not confine the flux within the core. Multiple switching regulators located in proximity to each other are particularly susceptible to mutual coupling of magnetic fluxes from each other’s open cores. In these situations, closed magnetic structures (such as a toroid, pot core, or E-core) are more appropriate. Regardless of the type and value of inductor used, the inductor never should carry more than its rated current. Doing so may cause the inductor to saturate, in which case the inductance quickly drops, and the inductor looks like a low-value resistor (from the dc resistance of the windings). As a result, switching current rises dramatically (until limited by the current-by-current limiting feature of the TL2575 and TL2575HV) and can result in overheating of the inductor and the IC itself. Note that different types of inductors have different saturation characteristics. Output Voltage Ripple and Transients As with any switching power supply, the output of the TL2575 and TL2575HV have a sawtooth ripple voltage at the switching frequency. Typically about 1% of the output voltage, this ripple is due mainly to the inductor sawtooth ripple current and the ESR of the output capacitor (see note on COUT). Furthermore, the output also may contain small voltage spikes at the peaks of the sawtooth waveform. This is due to the fast switching of the output switch and the parasitic inductance of COUT. These voltage spikes can be minimized through the use of low-inductance capacitors. There are several ways to reduce the output ripple voltage: a larger inductor, a larger COUT, or both. Another method is to use a small LC filter (20 mH and 100 mF) at the output. This filter can reduce the output ripple voltage by a factor of 10 (see Figure 1). Feedback Connection FEEDBACK must be wired to VOUT. The resistor should be in close proximity to the regulator, and should be less than 100 kΩ to minimize noise pickup. ON/OFF Input ON/OFF should be grounded or be a low-level TTL voltage (typically