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LM2588S-3.3/NOPB

LM2588S-3.3/NOPB

  • 厂商:

    BURR-BROWN(德州仪器)

  • 封装:

    TO263-7

  • 描述:

    LM2588 5A FLYBACK REGULATOR WITH

  • 数据手册
  • 价格&库存
LM2588S-3.3/NOPB 数据手册
Product Folder Order Now Support & Community Tools & Software Technical Documents LM2588 SNVS117E – APRIL 1998 – REVISED JUNE 2019 LM2588 5-A Flyback Regulator With Shutdown 1 Features 3 Description • • • • • The LM2588 series of regulators are monolithic integrated circuits specifically designed for flyback, step-up (boost), and forward converter applications. The device is available in 4 different output voltage versions: 3.3 V, 5 V, 12 V, and adjustable. 1 • • • • • • • • Requires Few External Components Family of Standard Inductors and Transformers NPN Output Switches 5 A, Can Stand Off 65 V Wide Input Voltage Range: 4 V to 40 V Adjustable Switching Frequency: 100 kHz to 200 kHz External Shutdown Capability Draws Less Than 60 μA When Shut Down Frequency Synchronization Current-mode Operation for Improved Transient Response, Line Regulation, and Current Limit Internal Soft-start Function Reduces In-rush Current During Start-up Output Transistor Protected by Current Limit, Undervoltage Lockout, and Thermal Shutdown System Output Voltage Tolerance of ±4% Max Over Line and Load Conditions Create a Custom Design Using the LM2588With the WEBENCH® Power Designer 2 Typical Applications • • • • Flyback Regulator Forward Converter Multiple-output Regulator Simple Boost Regulator Requiring a minimum number of external components, these regulators are cost effective, and simple to use. Included in this data sheet are typical circuits of boost and flyback regulators. Also listed are selector guides for diodes and capacitors and a family of standard inductors and flyback transformers designed to work with these switching regulators. The power switch is a 5-A NPN device that can stand-off 65 V. Protecting the power switch are current and thermal limiting circuits, and an undervoltage lockout circuit. This IC contains an adjustable frequency oscillator that can be programmed up to 200 kHz. The oscillator can also be synchronized with other devices, so that multiple devices can operate at the same switching frequency. Other features include soft start mode to reduce inrush current during start up, and current mode control for improved rejection of input voltage and output load transients and cycle-by-cycle current limiting. The device also has a shutdown pin, so that it can be turned off externally. An output voltage tolerance of ±4%, within specified input voltages and output load conditions, is ensured for the power supply system. Device Information(1) PART NUMBER LM2588 PACKAGE BODY SIZE (NOM) TO-220 (7) 10.1 mm × 8.89 mm DDPAK /TO-263 (7) 14.986 mm × 10.16 mm (1) For all available packages, see the orderable addendum at the end of the data sheet. Flyback Regulator 1 An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectual property matters and other important disclaimers. PRODUCTION DATA. LM2588 SNVS117E – APRIL 1998 – REVISED JUNE 2019 www.ti.com Table of Contents 1 2 3 4 5 6 Features .................................................................. Typical Applications .............................................. Description ............................................................. Revision History..................................................... Pin Configurations................................................. Specifications......................................................... 1 1 1 2 3 4 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 Absolute Maximum Ratings ...................................... 4 ESD Ratings.............................................................. 4 Recommended Operating Ratings............................ 4 Electrical Characteristics: 3.3 V ................................ 5 Electrical Characteristics: 5 V ................................... 5 Electrical Characteristics: 12 V ................................. 6 Electrical Characteristics: Adjustable ........................ 6 Electrical Characteristics: All Output Voltage Versions ...................................................................................7 6.9 Typical Characteristics .............................................. 9 7 Detailed Description ............................................ 12 7.1 Overview ................................................................. 12 7.2 Functional Block Diagram ....................................... 12 7.3 Feature Description................................................. 12 8 Application and Implementation ........................ 18 8.1 Application Information............................................ 18 8.2 Typical Applications ............................................... 18 8.3 System Examples ................................................... 28 9 Layout ................................................................... 29 9.1 Layout Guidelines ................................................... 29 9.2 Layout Example ...................................................... 29 9.3 Heat Sink/Thermal Considerations ......................... 29 10 Device and Documentation Support ................. 31 10.1 10.2 10.3 10.4 10.5 10.6 Device Support...................................................... Receiving Notification of Documentation Updates Community Resources.......................................... Trademarks ........................................................... Electrostatic Discharge Caution ............................ Glossary ................................................................ 31 31 31 31 32 32 11 Mechanical, Packaging, and Orderable Information ........................................................... 32 4 Revision History NOTE: Page numbers for previous revisions may differ from page numbers in the current version. Changes from Revision D (April 2013) to Revision E Page • Editorial changes only; no technical revisions ....................................................................................................................... 1 • Added links for WEBENCH ................................................................................................................................................... 1 Changes from Revision C (April 2013) to Revision D • 2 Page Changed layout of National Semiconductor data sheet to TI format .................................................................................... 1 Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 LM2588 www.ti.com SNVS117E – APRIL 1998 – REVISED JUNE 2019 5 Pin Configurations NDZ Package 7-Pin TO-220 Top View, Bent, Staggered Leads KTW Package 7-Pin DDPAK/TO-263 Top View NDZ Package 7-Pin TO-220 Side View; Bent, Staggered Leads KTW Package 7-Pin DDPAK/TO-263 Side View Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 3 LM2588 SNVS117E – APRIL 1998 – REVISED JUNE 2019 www.ti.com 6 Specifications 6.1 Absolute Maximum Ratings See (1) (2) −0.4V ≤ VIN ≤ 45V Input Voltage −0.4V ≤ VSW ≤ 65V Switch Voltage Switch Current (3) Internally Limited Compensation Pin Voltage −0.4V ≤ VCOMP ≤ 2.4V Feedback Pin Voltage −0.4V ≤ VFB ≤ 2 VOUT −0.4V ≤ VSH ≤ 6V ON /OFF Pin Voltage −0.4V ≤ VSYNC ≤ 2V Sync Pin Voltage Power Dissipation (4) Internally Limited −65°C to +150°C Storage Temperature Range Lead Temperature (Soldering, 10 sec.) 260°C Maximum Junction Temperature (4) (1) (2) (3) (4) 150°C Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. These ratings apply when the current is limited to less than 1.2 mA for pins 1, 2, 3, and 6. Operating ratings indicate conditions for which the device is intended to be functional, but device parameter specifications may not be ensured under these conditions. For ensured specifications and test conditions, see the Electrical Characteristics. If Military/Aerospace specified devices are required, contact the TI Sales Office/ Distributors for availability and specifications. Note that switch current and output current are not identical in a step-up regulator. Output current cannot be internally limited when the LM2588 is used as a step-up regulator. To prevent damage to the switch, the output current must be externally limited to 5A. However, output current is internally limited when the LM2588 is used as a flyback regulator (see the section for more information). The junction temperature of the device (TJ) is a function of the ambient temperature (TA), the junction-to-ambient thermal resistance (θJA), and the power dissipation of the device (PD). A thermal shutdown will occur if the temperature exceeds the maximum junction temperature of the device: PD × θJA + TA(MAX) ≥ TJ(MAX). For a safe thermal design, check that the maximum power dissipated by the device is less than: PD ≤ [TJ(MAX) − TA(MAX)]/θJA. When calculating the maximum allowable power dissipation, derate the maximum junction temperature—this ensures a margin of safety in the thermal design. 6.2 ESD Ratings V(ESD) (1) Electrostatic discharge (minimum) Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001 (C = 100 pF, R = 1.5 kΩ) VALUE UNIT 2000 V (1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process. 6.3 Recommended Operating Ratings 4V ≤ VIN ≤ 40V Supply Voltage 0V ≤ VSW ≤ 60V Output Switch Voltage ISW ≤ 5.0A Output Switch Current −40°C ≤ TJ ≤ +125°C Junction Temperature Range 4 Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 LM2588 www.ti.com SNVS117E – APRIL 1998 – REVISED JUNE 2019 6.4 Electrical Characteristics: 3.3 V Specifications with standard type face are for TJ = 25°C, and those in boldtype face apply over full Operating Temperature Range. Unless otherwise specified, VIN = 5V. PARAMETER TEST CONDITIONS TYP MIN MAX UNIT 3.17/3.14 3.43/3.46 V SYSTEM PARAMETERS Test Circuit of Figure 54 (1) VOUT Output Voltage VIN = 4V to 12V ILOAD = 400 mA to 1.75A 3.3 ΔVOUT/ ΔVIN Line Regulation VIN = 4V to 12V ILOAD = 400 mA 20 50/100 mV ΔVOUT/ ΔILOAD Load Regulation VIN = 12V ILOAD = 400 mA to 1.75A 20 50/100 mV η Efficiency VIN = 12V, ILOAD = 1A 75 Measured at Feedback Pin VCOMP = 1.0V 3.3 UNIQUE DEVICE PARAMETERS VREF Output Reference Voltage ΔVREF Reference Voltage Line VIN = 4V to 40V Regulation GM Error Amp Transconductance ICOMP = −30 μA to +30 μA VCOMP = 1.0V AVOL Error Amp Voltage Gain VCOMP = 0.5V to 1.6V RCOMP = 1.0 MΩ (3) (1) (2) (3) % (2) 3.242/3.234 3.358/3.366 V 2.0 mV 1.193 0.678 260 151/75 2.259 mmho V/V External components such as the diode, inductor, input and output capacitors can affect switching regulator performance. When the LM2588 is used as shown in Figure 54 and Figure 55, system performance will be as specified by the system parameters. All room temperature limits are 100% production tested, and all limits at temperature extremes are specified via correlation using standard Statistical Quality Control (SQC) methods. A 1.0 MΩ resistor is connected to the compensation pin (which is the error amplifier output) to ensure accuracy in measuring AVOL. 6.5 Electrical Characteristics: 5 V Specifications with standard type face are for TJ = 25°C, and those in bold type face apply over full Operating Temperature Range. Unless otherwise specified, VIN = 5V. PARAMETER TEST CONDITIONS SYSTEM PARAMETERS Test Circuit of Figure 54 TYP MIN MAX UNIT 4.80/4.75 5.20/5.25 V (1) VOUT Output Voltage VIN = 4V to 12V ILOAD = 500 mA to 1.45A 5.0 ΔVOUT/ ΔVIN Line Regulation VIN = 4V to 12V ILOAD = 500 mA 20 50/100 mV ΔVOUT/ ΔILOAD Load Regulation VIN = 12V ILOAD = 500 mA to 1.45A 20 50/100 mV η Efficiency VIN = 12V, ILOAD = 750 mA 80 Measured at Feedback Pin VCOMP = 1.0V 5.0 UNIQUE DEVICE PARAMETERS VREF Output Reference Voltage ΔVREF Reference Voltage Line VIN = 4V to 40V Regulation GM Error Amp Transconductance ICOMP = −30 μA to +30 μA VCOMP = 1.0V AVOL Error Amp Voltage Gain VCOMP = 0.5V to 1.6V RCOMP = 1.0 MΩ (3) (1) (2) (3) % (2) 4.913/4.900 5.088/5.100 V 3.3 mV 0.750 0.447 165 99/49 1.491 mmho V/V External components such as the diode, inductor, input and output capacitors can affect switching regulator performance. When the LM2588 is used as shown in Figure 54 and Figure 55, system performance will be as specified by the system parameters. All room temperature limits are 100% production tested, and all limits at temperature extremes are specified via correlation using standard Statistical Quality Control (SQC) methods. A 1.0 MΩ resistor is connected to the compensation pin (which is the error amplifier output) to ensure accuracy in measuring AVOL. Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 5 LM2588 SNVS117E – APRIL 1998 – REVISED JUNE 2019 www.ti.com 6.6 Electrical Characteristics: 12 V Specifications with standard type face are for TJ = 25°C, and those in bold type face apply over full Operating Temperature Range. Unless otherwise specified, VIN = 5V. PARAMETER TEST CONDITIONS TYP MIN MAX UNIT 12.0 11.52/11.40 12.48/12.60 V 20 100/200 mV 20 100/200 mV SYSTEM PARAMETERS Test Circuit of Figure 55 (1) VOUT Output Voltage VIN = 4V to 10V ILOAD = 300 mA to 1.2A ΔVOUT/ ΔVIN Line Regulation ΔVOUT/ ΔILOAD Load Regulation η Efficiency ILOAD = 300 mA VIN = 10V ILOAD = 300 mA to 1.2A UNIQUE DEVICE PARAMETERS VREF VIN = 4V to 10V VIN = 10V, ILOAD = 1A Output Reference Voltage Measured at Feedback Pin Reference Voltage Line VIN = 4V to 40V Regulation GM Error Amp Transconductance ICOMP = −30 μA to +30 μA Error Amp Voltage Gain VCOMP = 0.5V to 1.6V (1) (2) (3) % 12.0 11.79/11.76 12.21/12.24 V VCOMP = 1.0V ΔVREF AVOL 90 (2) 7.8 mV 0.328 0.186 70 41/21 0.621 mmho VCOMP = 1.0V V/V RCOMP = 1.0 MΩ (3) External components such as the diode, inductor, input and output capacitors can affect switching regulator performance. When the LM2588 is used as shown in Figure 54 and Figure 55, system performance will be as specified by the system parameters. All room temperature limits are 100% production tested, and all limits at temperature extremes are specified via correlation using standard Statistical Quality Control (SQC) methods. A 1.0 MΩ resistor is connected to the compensation pin (which is the error amplifier output) to ensure accuracy in measuring AVOL. 6.7 Electrical Characteristics: Adjustable Specifications with standard type face are for TJ = 25°C, and those in bold type face apply over full Operating Temperature Range. Unless otherwise specified, VIN = 5V. PARAMETER TEST CONDITIONS TYP MIN MAX UNIT 12.0 11.52/11.40 12.48/12.60 V SYSTEM PARAMETERS Test Circuit of Figure 55 (1) VOUT Output Voltage VIN = 4V to 10V ILOAD = 300 mA to 1.2A ΔVOUT/ ΔVIN Line Regulation VIN = 4V to 10V ILOAD = 300 mA 20 100/200 mV ΔVOUT/ ΔILOAD Load Regulation VIN = 10V ILOAD = 300 mA to 1.2A 20 100/200 mV η Efficiency VIN = 10V, ILOAD = 1A 90 UNIQUE DEVICE PARAMETERS VREF Output Reference Voltage ΔVREF Reference Voltage Line VIN = 4V to 40V Regulation GM Error Amp Transconductance ICOMP = −30 μA to +30 μA VCOMP = 1.0V AVOL Error Amp Voltage Gain IB Error Amp Input Bias Current (1) (2) (3) 6 % (2) Measured at Feedback Pin VCOMP = 1.0V 1.230 1.208/1.205 1.252/1.255 1.5 V mV 3.200 1.800 VCOMP = 0.5V to 1.6V RCOMP = 1.0 MΩ (3) 670 400/200 VCOMP = 1.0V 125 6.000 mmho V/V 425/600 nA External components such as the diode, inductor, input and output capacitors can affect switching regulator performance. When the LM2588 is used as shown in Figure 54 and Figure 55, system performance will be as specified by the system parameters. All room temperature limits are 100% production tested, and all limits at temperature extremes are specified via correlation using standard Statistical Quality Control (SQC) methods. A 1.0 MΩ resistor is connected to the compensation pin (which is the error amplifier output) to ensure accuracy in measuring AVOL. Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 LM2588 www.ti.com SNVS117E – APRIL 1998 – REVISED JUNE 2019 6.8 Electrical Characteristics: All Output Voltage Versions (1) Specifications with standard type face are for TJ = 25°C, and those in bold type face apply over full Operating Temperature Range. Unless otherwise specified, VIN = 5V. PARAMETER MAX UNIT Switch Off (2) TEST CONDITIONS TYP 11 MIN 15.5/16.5 mA ISWITCH = 3.0A 85 140/165 mA VSH = 3V 16 100/300 μA 3.05 3.75 V 85/75 115/125 kHz IS Input Supply Current IS/D Shutdown Input Supply Current VUV Input Supply Undervoltage Lockout RLOAD = 100Ω 3.30 fO Oscillator Frequency Measured at Switch Pin RLOAD = 100Ω, VCOMP = 1.0V Freq. Adj. Pin Open (Pin 1) 100 RSET = 22 kΩ 200 kHz 25 kHz fSC Short-Circuit Frequency Measured at Switch Pin RLOAD = 100Ω VFEEDBACK = 1.15V VEAO Error Amplifier Output Swing Upper Limit (3) 2.8 Lower Limit (2) 0.25 IEAO Error Amp Output Current (Source or Sink) See (4) 165 ISS Soft Start Current VFEEDBACK = 0.92V VCOMP = 1.0V DMAX Maximum Duty Cycle IL 2.6/2.4 V 0.40/0.55 V 110/70 260/320 μA 11.0 8.0/7.0 17.0/19.0 μA RLOAD = 100Ω (3) 98 93/90 Switch Leakage Current Switch Off VSWITCH = 60V 15 VSUS Switch Sustaining Voltage dV/dT = 1.5V/ns VSAT Switch Saturation Voltage ISWITCH = 5.0A ICL NPN Switch Current Limit VSTH Synchronization Threshold Voltage ISYNC % 300/600 65 0.7 μA V 1.1/1.4 V 6.5 5.0 9.5 A FSYNC = 200 kHz VCOMP = 1V, VIN = 5V 0.75 0.625/0.40 0.875/1.00 V Synchronization Pin Current VIN = 5V VCOMP = 1V, VSYNC = VSTH 100 200 μA VSHTH ON /OFF Pin (Pin 1) Threshold Voltage VCOMP = 1V (5) ISH ON /OFF Pin (Pin 1) Current VCOMP = 1V VSH = VSHTH (1) (2) (3) (4) (5) 1.6 1.0/0.8 2.2/2.4 V 40 15/10 65/75 μA All room temperature limits are 100% production tested, and all limits at temperature extremes are specified via correlation using standard Statistical Quality Control (SQC) methods. To measure this parameter, the feedback voltage is set to a high value, depending on the output version of the device, to force the error amplifier output low and the switch off. To measure this parameter, the feedback voltage is set to a low value, depending on the output version of the device, to force the error amplifier output high and the switch on. To measure the worst-case error amplifier output current, the LM2588 is tested with the feedback voltage set to its low value (specified in Note 3 under the Electrical Characteristics: All Output Voltage Versions (1) table) and at its high value (specified in Note 2 under the Electrical Characteristics: All Output Voltage Versions (1) table). When testing the minimum value, do not sink current from this pin—isolate it with a diode. If current is drawn from this pin, the frequency adjust circuit will begin operation (see Figure 20). Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 7 LM2588 SNVS117E – APRIL 1998 – REVISED JUNE 2019 www.ti.com Electrical Characteristics: All Output Voltage Versions (1) (continued) Specifications with standard type face are for TJ = 25°C, and those in bold type face apply over full Operating Temperature Range. Unless otherwise specified, VIN = 5V. PARAMETER θJA θJA θJC θJA θJA θJA θJC Thermal Resistance TEST CONDITIONS TYP NDZ Package, Junction to Ambient (6) NDZ Package, Junction to Ambient (7) NDZ Package, Junction to Case 65 45 2 Junction to Ambient (8) Junction to Ambient (9) Junction to 56 35 26 2 KTW Package, KTW Package, KTW Package, Ambient (10) KTW Package, MIN MAX UNIT °C/W Junction to Case (6) Junction to ambient thermal resistance (no external heat sink) for the 7 lead TO-220 package mounted vertically, with ½ inch leads in a socket, or on a PC board with minimum copper area. (7) Junction to ambient thermal resistance (no external heat sink) for the 7 lead TO-220 package mounted vertically, with ½ inch leads soldered to a PC board containing approximately 4 square inches of (1 oz.) copper area surrounding the leads. (8) Junction to ambient thermal resistance for the 7 lead TO-263 mounted horizontally against a PC board area of 0.136 square inches (the same size as the TO-263 package) of 1 oz. (0.0014 in. thick) copper. (9) Junction to ambient thermal resistance01242001 for the 7 lead TO-263 mounted horizontally against a PC board area of 0.4896 square inches (3.6 times the area of the TO-263 package) of 1 oz. (0.0014 in. thick) copper. (10) Junction to ambient thermal resistance for the 7 lead TO-263 mounted horizontally against a PC board copper area of 1.0064 square inches (7.4 times the area of the TO-263 package) of 1 oz. (0.0014 in. thick) copper. Additional copper area will reduce thermal resistance further. See the thermal model in Switchers Made Simple® software. 8 Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 LM2588 www.ti.com SNVS117E – APRIL 1998 – REVISED JUNE 2019 6.9 Typical Characteristics Figure 1. Supply Current vs Temperature Figure 2. Reference Voltage vs Temperature Figure 3. ΔReference Voltage vs Supply Voltage Figure 4. Supply Current vs Switch Current Figure 5. Current Limit vs Temperature Figure 6. Feedback Pin Bias Current vs Temperature Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 9 LM2588 SNVS117E – APRIL 1998 – REVISED JUNE 2019 www.ti.com Typical Characteristics (continued) 10 Figure 7. Switch Saturation Voltage vs Temperature Figure 8. Switch Transconductance vs Temperature Figure 9. Oscillator Frequency vs Temperature Figure 10. Error Amp Transconductance vs Temperature Figure 11. Error Amp Voltage Gain vs Temperature Figure 12. Short Circuit Frequency vs Temperature Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 LM2588 www.ti.com SNVS117E – APRIL 1998 – REVISED JUNE 2019 Typical Characteristics (continued) Figure 13. Shutdown Supply Current vs Temperature Figure 14. ON /Off Pin Current vs Voltage Figure 15. Oscillator Frequency vs Resistance Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 11 LM2588 SNVS117E – APRIL 1998 – REVISED JUNE 2019 www.ti.com 7 Detailed Description 7.1 Overview The LM2588 series of regulators are monolithic integrated circuits specifically designed for flyback, step-up (boost), and forward converter applications. The device is available in 4 different output voltage versions: 3.3 V, 5 V, 12 V, and adjustable. Requiring a minimum number of external components, these regulators are cost effective, and simple to use. Included in the datasheet are typical circuits of boost and flyback regulators. Also listed are selector guides for diodes and capacitors and a family of standard inductors and flyback transformers designed to work with these switching regulators. 7.2 Functional Block Diagram For Fixed Versions 3.3V, R1 = 3.4k, R2 = 2k5.0V, R1 = 6.15k, R2 = 2k12V, R1 = 8.73k, R2 = 1kFor Adj. VersionR1 = Short (0Ω), R2 = Open 7.3 Feature Description 7.3.1 Flyback Regulator Operation The operation of a flyback regulator is as follows (refer to Figure 16): when the switch is on, current flows through the primary winding of the transformer, T1, storing energy in the magnetic field of the transformer. Note that the primary and secondary windings are out of phase, so no current flows through the secondary when current flows through the primary. When the switch turns off, the magnetic field collapses, reversing the voltage polarity of the primary and secondary windings. Now rectifier D1 is forward biased and current flows through it, releasing the energy stored in the transformer. This produces voltage at the output. The output voltage is controlled by modulating the peak switch current. This is done by feeding back a portion of the output voltage to the error amp, which amplifies the difference between the feedback voltage and a 1.23-V reference. The error amp output voltage is compared to a ramp voltage proportional to the switch current (in other words, inductor current during the switch on-time). The comparator terminates the switch on time when the two voltages are equal, thereby controlling the peak switch current to maintain a constant output voltage. 12 Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 LM2588 www.ti.com SNVS117E – APRIL 1998 – REVISED JUNE 2019 Feature Description (continued) As shown in Figure 16, the LM2588 can be used as a flyback regulator by using a minimum number of external components. The switching waveforms of this regulator are shown in Figure 18. Typical characteristics observed during the operation of this circuit are shown in Figure 19. Figure 16. 12-V Flyback Regulator Design Example 7.3.2 Step-Up (Boost) Regulator Operation Figure 17 shows the LM2588 used as a step-up (boost) regulator. This is a switching regulator that produces an output voltage greater than the input supply voltage. A brief explanation of how the LM2588 boost regulator works is as follows (refer to Figure 17). When the NPN switch turns on, the inductor current ramps up at the rate of VIN/L, storing energy in the inductor. When the switch turns off, the lower end of the inductor flies above VIN, discharging its current through diode (D) into the output capacitor (COUT) at a rate of (VOUT − VIN)/L. Thus, energy stored in the inductor during the switch on-time is transferred to the output during the switch off time. The output voltage is controlled by adjusting the peak switch current, as described in the section. Figure 17. 12-V Boost Regulator By adding a small number of external components (as shown in Figure 17), the LM2588 can be used to produce a regulated output voltage that is greater than the applied input voltage. The switching waveforms observed during the operation of this circuit are shown in . Typical performance of this regulator is shown in . Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 13 LM2588 SNVS117E – APRIL 1998 – REVISED JUNE 2019 www.ti.com Feature Description (continued) A: Switch Voltage, 10V/div B: Switch Current, 5A/div C: Output Rectifier Current, 5A/div D: Output Ripple Voltage, 100 mV/div AC-Coupled Figure 18. Switching Waveforms Figure 19. VOUT Response To Load Current Step 7.3.3 Shutdown Control A feature of the LM2588 is its ability to be shut down using the ON /OFF pin (pin 1). This feature conserves input power by turning off the device when it is not in use. For proper operation, an isolation diode is required (as shown in Figure 20). The device will shut down when 3 V or greater is applied on the ON /OFF pin, sourcing current into pin 1. In shut down mode, the device draws typically 56 μA of supply current (16 μA to VIN and 40 μA to the ON /OFF pin). To turn the device back on, leave pin 1 floating, using an (isolation) diode, as shown in Figure 20 (for normal operation, do not source or sink current to or from this pin—see the next section). Figure 20. Shutdown Operation 7.3.4 Frequency Adjustment The switching frequency of the LM2588 can be adjusted with the use of an external resistor. This feature allows the user to optimize the size of the magnetics and the output capacitor(s) by tailoring the operating frequency. A resistor connected from pin 1 (the Freq. Adj. pin) to ground will set the switching frequency from 100 kHz to 200 kHz (maximum). As shown in Figure 20, the pin can be used to adjust the frequency while still providing the shut down function. A curve in the Performance Characteristics Section graphs the resistor value to the corresponding switching frequency. The table in Table 1 shows resistor values corresponding to commonly used frequencies. However, changing the LM2588's operating frequency from its nominal value of 100 kHz changes the magnetics selection and compensation component values. 14 Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 LM2588 www.ti.com SNVS117E – APRIL 1998 – REVISED JUNE 2019 Feature Description (continued) Table 1. Frequency Setting Resistor Guide RSET(kΩ) FREQUENCY (kHz) Open 100 200 125 47 150 33 175 22 200 7.3.5 Frequency Synchronization Another feature of the LM2588 is the ability to synchronize the switching frequency to an external source, using the sync pin (pin 6). This feature allows the user to parallel multiple devices to deliver more output power. A negative falling pulse applied to the sync pin will synchronize the LM2588 to an external oscillator (see Figure 21 and Figure 22). Use of this feature enables the LM2588 to be synchronized to an external oscillator, such as a system clock. This operation allows multiple power supplies to operate at the same frequency, thus eliminating frequency-related noise problems. Figure 21. Frequency Synchronization The scope photo in Figure 22 shows a LM2588 12V Boost Regulator synchronized to a 200-kHz signal. There is a 700 ns delay between the falling edge of the sync signal and the turning on of the switch. Figure 22. Waveforms Of A Synchronized 12-V Boost Regulator Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 15 LM2588 SNVS117E – APRIL 1998 – REVISED JUNE 2019 www.ti.com 7.3.6 Programming Output Voltage (Selecting R1 And R2) Referring to the adjustable regulator in Figure 23, the output voltage is programmed by the resistors R1 and R2 by the following formula: VOUT = VREF (1 + R1/R2) where VREF = 1.23V (1) Resistors R1 and R2 divide the output voltage down so that it can be compared with the 1.23-V internal reference. With R2 between 1k and 5k, R1 is: R1 = R2 (VOUT/VREF − 1) wher where • e VREF = 1.23 V (2) For best temperature coefficient and stability with time, use 1% metal film resistors. 7.3.7 Short-Circuit Condition Due to the inherent nature of boost regulators, when the output is shorted (see Figure 23 ), current flows directly from the input, through the inductor and the diode, to the output, bypassing the switch. The current limit of the switch does not limit the output current for the entire circuit. To protect the load and prevent damage to the switch, the current must be externally limited, either by the input supply or at the output with an external current limit circuit. The external limit should be set to the maximum switch current of the device, which is 5 A. In a flyback regulator application (Figure 24 ), using the standard transformers, the LM2588 survives a short circuit to the main output. When the output voltage drops to 80% of its nominal value, the frequency will drop to 25 kHz. With a lower frequency, off times are larger. With the longer off times, the transformer can release all of its stored energy before the switch turns back on. Hence, the switch turns on initially with zero current at its collector. In this condition, the switch current limit will limit the peak current, saving the device. Figure 23. Boost Regulator 16 Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 LM2588 www.ti.com SNVS117E – APRIL 1998 – REVISED JUNE 2019 Figure 24. Flyback Regulator Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 17 LM2588 SNVS117E – APRIL 1998 – REVISED JUNE 2019 www.ti.com 8 Application and Implementation NOTE Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality. 8.1 Application Information The LM2586 series of regulators are monolithic integrated circuits specifically designed for flyback, step-up (boost), and forward converter applications. Requiring a minimum number of external components, these regulators are cost effective, and simple to use. Included in the datasheet are typical circuits of boost and flyback regulators. Also listed are selector guides for diodes and capacitors and a family of standard inductors and flyback transformers designed to work with these switching regulators. 8.2 Typical Applications 8.2.1 Typical Flyback Regulator Applications Figure 25 through Figure 30 show six typical flyback applications, varying from single output to triple output. Each drawing contains the part number(s) and manufacturer(s) for every component except the transformer. For the transformer part numbers and manufacturers' names, see Table 2. For applications with different output voltages—requiring the LM2588-ADJ—or different output configurations that do not match the standard configurations, refer to the Switchers Made Simple software. Figure 25. Single-Output Flyback Regulator 18 Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 LM2588 www.ti.com SNVS117E – APRIL 1998 – REVISED JUNE 2019 Typical Applications (continued) Figure 26. Single-Output Flyback Regulator Figure 27. Single-Output Flyback Regulator Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 19 LM2588 SNVS117E – APRIL 1998 – REVISED JUNE 2019 www.ti.com Typical Applications (continued) Figure 28. Dual-Output Flyback Regulator Figure 29. Dual-Output Flyback Regulator 20 Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 LM2588 www.ti.com SNVS117E – APRIL 1998 – REVISED JUNE 2019 Typical Applications (continued) Figure 30. Triple-Output Flyback Regulator 8.2.1.1 Design Requirements 8.2.1.1.1 Transformer Selection (T) Table 2 lists the standard transformers available for flyback regulator applications. Included in the table are the turns ratio(s) for each transformer, as well as the output voltages, input voltage ranges, and the maximum load currents for each circuit. Table 2. Transformer Selection Table APPLICATIONS Transformers VIN Figure 25 Figure 26 Figure 27 Figure 28 Figure 29 T1 T1 T1 T2 T3 Figure 30 T4 4V–6V 4V–6V 8V–16V 4V–6V 18V–36V 18V–36V VOUT1 3.3V 5V 12V 12V 12V 5V IOUT1 (Max) 1.8A 1.4A 1.2A 0.3A 1A 2.5A 1 1 1 2.5 0.8 0.35 VOUT2 −12V −12V 12V IOUT2 (Max) 0.3A 1A 0.5A 2.5 0.8 N1 N2 0.8 VOUT3 −12V IOUT3 (Max) 0.5A N3 0.8 Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 21 LM2588 SNVS117E – APRIL 1998 – REVISED JUNE 2019 www.ti.com Table 3. Transformer Manufacturer Guide Transformer Type (1) (2) (3) (4) Manufacturers' Part Numbers Coilcraft (1) Coilcraft Surface Mount (1) Pulse Surface Mount (2) Renco (3) Schott (4) T1 Q4434-B Q4435-B PE-68411 RL-5530 67141450 T2 Q4337-B Q4436-B PE-68412 RL-5531 67140860 T3 Q4343-B — PE-68421 RL-5534 67140920 T4 Q4344-B — PE-68422 RL-5535 67140930 Coilcraft Inc.,: Phone: (800) 322-26451102 Silver Lake Road, Cary, IL 60013: Fax: (708) 639-1469European Headquarters, 21 Napier Place: Phone: +44 1236 730 595Wardpark North, Cumbernauld, Scotland G68 0LL: Fax: +44 1236 730 627 Pulse Engineering Inc.,: Phone: (619) 674-810012220 World Trade Drive, San Diego, CA 92128: Fax: (619) 674-8262European Headquarters, Dunmore Road: Phone: +353 93 24 107Tuam, Co. Galway, Ireland: Fax: +353 93 24 459 Renco Electronics Inc.,: Phone: (800) 645-582860 Jeffryn Blvd. East, Deer Park, NY 11729: Fax: (516) 586-5562 Schott Corp.,: Phone: (612) 475-11731000 Parkers Lane Road, Wayzata, MN 55391: Fax: (612) 475-1786 8.2.1.1.2 Transformer Footprints Figure 31 through Figure 48 show the footprints of each transformer, listed in Table 3. Figure 31. T1 - Top View Coilcraft Q4434-B Figure 32. T2 - Top View Coilcraft Q4337-B Figure 33. T3 - Top View Coilcraft Q4343-B Figure 34. T4 - Top View Coilcraft Q4344-B Figure 35. T1 - Top View Coilcraft Q4435-B (Surface Mount) 22 Figure 36. T2 - Top View Coilcraft Q4436-B (Surface Mount) Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 LM2588 www.ti.com SNVS117E – APRIL 1998 – REVISED JUNE 2019 Figure 37. T1 - Top View Pulse PE-68411 (Surface Mount) Figure 38. T2 - Top View Pulse PE-68412 (Surface Mount) Figure 39. T3 - Top View Pulse PE-68421 (Surface Mount) Figure 40. T4 - Top View Pulse PE-68422 (Surface Mount) Figure 41. T1 - Top View Renco RL-5530 Figure 42. T2 - Top View Renco RL-5531 Figure 43. T3 - Top View Renco RL-5534 Figure 44. T4 - Top View Renco RL-5535 Figure 45. T1 - Top View Schott 67141450 Figure 46. T2 - Top View Schott 67140860 Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 23 LM2588 SNVS117E – APRIL 1998 – REVISED JUNE 2019 www.ti.com Figure 48. T4 - Top View Schott 67140930 Figure 47. T3 - Top View Schott 67140920 8.2.1.2 Detailed Design Procedure 8.2.1.2.1 Custom Design With WEBENCH® Tools Click here to create a custom design using the LM2588 device with the WEBENCH® Power Designer. 1. Start by entering the input voltage (VIN), output voltage (VOUT), and output current (IOUT) requirements. 2. Optimize the design for key parameters such as efficiency, footprint, and cost using the optimizer dial. 3. Compare the generated design with other possible solutions from Texas Instruments. The WEBENCH Power Designer provides a customized schematic along with a list of materials with real-time pricing and component availability. In most cases, these actions are available: • Run electrical simulations to see important waveforms and circuit performance • Run thermal simulations to understand board thermal performance • Export customized schematic and layout into popular CAD formats • Print PDF reports for the design, and share the design with colleagues Get more information about WEBENCH tools at www.ti.com/WEBENCH. 8.2.1.2.2 Flyback Regulator Input Capacitors A flyback regulator draws discontinuous pulses of current from the input supply. Therefore, there are two input capacitors needed in a flyback regulator—one for energy storage and one for filtering (see Figure 24). Both are required due to the inherent operation of a flyback regulator. To keep a stable or constant voltage supply to the LM2588, a storage capacitor (≥ 100 μF) is required. If the input source is a rectified DC supply and/or the application has a wide temperature range, the required rms current rating of the capacitor might be very large. This means a larger value of capacitance or a higher voltage rating will be needed for the input capacitor. The storage capacitor will also attenuate noise which may interfere with other circuits connected to the same input supply voltage. In addition, a small bypass capacitor is required due to the noise generated by the input current pulses. To eliminate the noise, insert a 1-μF ceramic capacitor between VIN and ground as close as possible to the device. 8.2.1.2.3 Switch Voltage Limits In a flyback regulator, the maximum steady-state voltage appearing at the switch, when it is off, is set by the transformer turns ratio, N, the output voltage, VOUT, and the maximum input voltage, VIN (maximum): VSW(OFF) = VIN (max) + (VOUT + VF) / N where • 24 VF is the forward biased voltage of the output diode, and is typically 0.5 V for Schottky diodes and 0.8V for ultra-fast recovery diodes (3) Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 LM2588 www.ti.com SNVS117E – APRIL 1998 – REVISED JUNE 2019 In certain circuits, there exists a voltage spike, VLL, superimposed on top of the steady-state voltage (see Figure 18, waveform A). Usually, this voltage spike is caused by the transformer leakage inductance and/or the output rectifier recovery time. To “clamp” the voltage at the switch from exceeding its maximum value, a transient suppressor in series with a diode is inserted across the transformer primary (as shown in the circuit in Figure 16 and other flyback regulator circuits throughout the datasheet). The schematic in Figure 24 shows another method of clamping the switch voltage. A single voltage transient suppressor (the SA51A) is inserted at the switch pin. This method clamps the total voltage across the switch, not just the voltage across the primary. If poor circuit layout techniques are used (see the section), negative voltage transients may appear on the Switch pin (pin 5). Applying a negative voltage (with respect to the IC's ground) to any monolithic IC pin causes erratic and unpredictable operation of that IC. This holds true for the LM2588 IC as well. When used in a flyback regulator, the voltage at the Switch pin (pin 5) can go negative when the switch turns on. The “ringing” voltage at the switch pin is caused by the output diode capacitance and the transformer leakage inductance forming a resonant circuit at the secondary(ies). The resonant circuit generates the “ringing” voltage, which gets reflected back through the transformer to the switch pin. There are two common methods to avoid this problem. One is to add an RC snubber around the output rectifier(s), as in Figure 24. The values of the resistor and the capacitor must be chosen so that the voltage at the Switch pin does not drop below −0.4 V. The resistor may range in value between 10Ω and 1 kΩ, and the capacitor will vary from 0.001 μF to 0.1 μF. Adding a snubber will (slightly) reduce the efficiency of the overall circuit. The other method to reduce or eliminate the “ringing” is to insert a Schottky diode clamp between pins 5 and 4 (ground), also shown in Figure 24. This prevents the voltage at pin 5 from dropping below −0.4 V. The reverse voltage rating of the diode must be greater than the switch off voltage. Figure 49. Input Line Filter 8.2.1.2.4 Output Voltage Limitations The maximum output voltage of a boost regulator is the maximum switch voltage minus a diode drop. In a flyback regulator, the maximum output voltage is determined by the turns ratio, N, and the duty cycle, D, by the equation: VOUT ≈ N × VIN × D / (1 − D) (4) The duty cycle of a flyback regulator is determined by the following equation: (5) Theoretically, the maximum output voltage can be as large as desired—just keep increasing the turns ratio of the transformer. However, there exists some physical limitations that prevent the turns ratio, and thus the output voltage, from increasing to infinity. The physical limitations are capacitances and inductances in the LM2588 switch, the output diode(s), and the transformer—such as reverse recovery time of the output diode (mentioned above). Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 25 LM2588 SNVS117E – APRIL 1998 – REVISED JUNE 2019 www.ti.com 8.2.1.2.5 Noisy Input Line Condition A small, low-pass RC filter should be used at the input pin of the LM2588 if the input voltage has an unusually large amount of transient noise, such as with an input switch that bounces. The circuit in Figure 49 demonstrates the layout of the filter, with the capacitor placed from the input pin to ground and the resistor placed between the input supply and the input pin. Note that the values of RIN and CIN shown in the schematic are good enough for most applications, but some readjusting might be required for a particular application. If efficiency is a major concern, replace the resistor with a small inductor (say 10 μH and rated at 200 mA). 8.2.1.2.6 Stability All current-mode controlled regulators can suffer from an instability, known as subharmonic oscillation, if they operate with a duty cycle above 50%. To eliminate subharmonic oscillations, a minimum value of inductance is required to ensure stability for all boost and flyback regulators. The minimum inductance is given by: where • VSAT is the switch saturation voltage and can be found in Typical Characteristics (6) 8.2.2 Typical Boost Regulator Applications Figure 50 and Figure 51 through Figure 53 show four typical boost applications—one fixed and three using the adjustable version of the LM2588. Each drawing contains the part number(s) and manufacturer(s) for every component. For the fixed 12-V output application, the part numbers and manufacturers' names for the inductor are listed in a table in Table 4. For applications with different output voltages, refer to the Switchers Made Simple™software. Figure 50. 5-V to 12-V Boost Regulator Figure 51. 12-V to 24-V Boost Regulator 26 Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 LM2588 www.ti.com SNVS117E – APRIL 1998 – REVISED JUNE 2019 Figure 52. 24-V to 36-V Boost Regulator *The LM2588 requires a heat sink in these applications. The size of the heat sink will depend on the maximum ambient temperature. To calculate the thermal resistance of the IC and the size of the heat sink needed, see the Heat Sink/Thermal Considerations section in Layout. Figure 53. 24-V to 48-V Boost Regulator 8.2.2.1 Design Requirements Table 4 contains a table of standard inductors, by part number and corresponding manufacturer, for the fixed output regulator of Figure 50. Table 4. Inductor Selection Table Coilcraft (1) R4793-A (1) (2) (3) (4) Pulse (2) PE-53900 Renco (3) RL-5472-5 Schott (4) 67146520 Coilcraft Inc.,: Phone: (800) 322-26451102 Silver Lake Road, Cary, IL 60013: Fax: (708) 639-1469European Headquarters, 21 Napier Place: Phone: +44 1236 730 595Wardpark North, Cumbernauld, Scotland G68 0LL: Fax: +44 1236 730 627 Pulse Engineering Inc.,: Phone: (619) 674-810012220 World Trade Drive, San Diego, CA 92128: Fax: (619) 674-8262European Headquarters, Dunmore Road: Phone: +353 93 24 107Tuam, Co. Galway, Ireland: Fax: +353 93 24 459 Renco Electronics Inc.,: Phone: (800) 645-582860 Jeffryn Blvd. East, Deer Park, NY 11729: Fax: (516) 586-5562 Schott Corp.,: Phone: (612) 475-11731000 Parkers Lane Road, Wayzata, MN 55391: Fax: (612) 475-1786 Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 27 LM2588 SNVS117E – APRIL 1998 – REVISED JUNE 2019 www.ti.com 8.2.2.2 Detailed Design Procedure See Detailed Design Procedure 8.3 System Examples 8.3.1 Test Circuits CIN1—100 μF, 25V Aluminum ElectrolyticCIN2—0.1 μF CeramicT—22 μH, 1:1 Schott #67141450D—1N5820COUT—680 μF, 16V Aluminum ElectrolyticCC—0.47 μF CeramicRC—2k Figure 54. 3.3-V and 5-V LM2588 CIN1—100 μF, 25V Aluminum ElectrolyticCIN2—0.1 μF CeramicL—15 μH, Renco #RL-5472-5D—1N5820COUT—680 μF, 16V Aluminum ElectrolyticCC—0.47 μF CeramicRC—2kFor 12V Devices: R1 = Short (0Ω) andR2 = OpenFor ADJ Devices: R1 = 48.75k, ±0.1% andR2 = 5.62k, ±0.1% Figure 55. 12-V and Adjustable LM2588 28 Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 LM2588 www.ti.com SNVS117E – APRIL 1998 – REVISED JUNE 2019 9 Layout 9.1 Layout 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, keep the length of the leads and traces as short as possible. Use single point grounding or ground plane construction for best results. Separate the signal grounds from the power grounds (as indicated in Figure 56). When using the Adjustable version, physically locate the programming resistors as near the regulator IC as possible, to keep the sensitive feedback wiring short. 9.2 Layout Example Figure 56. Circuit Board Layout 9.3 Heat Sink/Thermal Considerations In many cases, a heat sink is not required to keep the LM2588 junction temperature within the allowed operating temperature range. For each application, to determine whether or not a heat sink will be required, the following must be identified: 1) Maximum ambient temperature (in the application). 2) Maximum regulator power dissipation (in the application). 3) Maximum allowed junction temperature (125°C for the LM2588). For a safe, conservative design, a temperature approximately 15°C cooler than the maximum junction temperature should be selected (110°C). 4) LM2588 package thermal resistances θJA and θJC (given in the Electrical Characteristics). Total power dissipated (PD) by the LM2588 can be estimated as follows: Boost: (7) VIN is the minimum input voltage, VOUT is the output voltage, N is the transformer turns ratio, D is the duty cycle, and ILOAD is the maximum load current (and ∑ILOAD is the sum of the maximum load currents for multiple-output flyback regulators). The duty cycle is given by: Boost: Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 29 LM2588 SNVS117E – APRIL 1998 – REVISED JUNE 2019 www.ti.com Heat Sink/Thermal Considerations (continued) where • • VF is the forward biased voltage of the diode and is typically 0.5V for Schottky diodes and 0.8V for fast recovery diodes VSAT is the switch saturation voltage and can be found in the Characteristic Curves. (8) When no heat sink is used, the junction temperature rise is: ΔTJ = PD • θJA. (9) Adding the junction temperature rise to the maximum ambient temperature gives the actual operating junction temperature: TJ = ΔTJ + TA. (10) If the operating junction temperature exceeds the maximum junction temperatue in item 3 above, then a heat sink is required. When using a heat sink, the junction temperature rise can be determined by the following: ΔTJ = PD • (θJC + θInterface + θHeat Sink) (11) Again, the operating junction temperature will be: TJ = ΔTJ + TA (12) As before, if the maximum junction temperature is exceeded, a larger heat sink is required (one that has a lower thermal resistance). Included in the Switchers Made Simple™ design software is a more precise (non-linear) thermal model that can be used to determine junction temperature with different input-output parameters or different component values. It can also calculate the heat sink thermal resistance required to maintain the regulator junction temperature below the maximum operating temperature. 30 Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 LM2588 www.ti.com SNVS117E – APRIL 1998 – REVISED JUNE 2019 10 Device and Documentation Support 10.1 Device Support 10.1.1 Third-Party Products Disclaimer TI'S PUBLICATION OF INFORMATION REGARDING THIRD-PARTY PRODUCTS OR SERVICES DOES NOT CONSTITUTE AN ENDORSEMENT REGARDING THE SUITABILITY OF SUCH PRODUCTS OR SERVICES OR A WARRANTY, REPRESENTATION OR ENDORSEMENT OF SUCH PRODUCTS OR SERVICES, EITHER ALONE OR IN COMBINATION WITH ANY TI PRODUCT OR SERVICE. 10.1.2 Development Support 10.1.2.1 Custom Design With WEBENCH® Tools Click here to create a custom design using the LM2586 device with the WEBENCH® Power Designer. 1. Start by entering the input voltage (VIN), output voltage (VOUT), and output current (IOUT) requirements. 2. Optimize the design for key parameters such as efficiency, footprint, and cost using the optimizer dial. 3. Compare the generated design with other possible solutions from Texas Instruments. The WEBENCH Power Designer provides a customized schematic along with a list of materials with real-time pricing and component availability. In most cases, these actions are available: • Run electrical simulations to see important waveforms and circuit performance • Run thermal simulations to understand board thermal performance • Export customized schematic and layout into popular CAD formats • Print PDF reports for the design, and share the design with colleagues Get more information about WEBENCH tools at www.ti.com/WEBENCH. 10.2 Receiving Notification of Documentation Updates To receive notification of documentation updates, navigate to the device product folder on ti.com. In the upper right corner, click on Alert me to register and receive a weekly digest of any product information that has changed. For change details, review the revision history included in any revised document. 10.3 Community Resources The following links connect to TI community resources. Linked contents are provided "AS IS" by the respective contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of Use. TI E2E™ Online Community TI's Engineer-to-Engineer (E2E) Community. Created to foster collaboration among engineers. At e2e.ti.com, you can ask questions, share knowledge, explore ideas and help solve problems with fellow engineers. Design Support TI's Design Support Quickly find helpful E2E forums along with design support tools and contact information for technical support. 10.4 Trademarks Switchers Made Simple, E2E are trademarks of Texas Instruments. WEBENCH is a registered trademark of Texas Instruments. Switchers Made Simple is a registered trademark of dcl_owner. All other trademarks are the property of their respective owners. Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 31 LM2588 SNVS117E – APRIL 1998 – REVISED JUNE 2019 www.ti.com 10.5 Electrostatic Discharge Caution This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. 10.6 Glossary SLYZ022 — TI Glossary. This glossary lists and explains terms, acronyms, and definitions. 11 Mechanical, Packaging, and Orderable Information The following pages include mechanical, packaging, and orderable information. This information is the most current data available for the designated devices. This data is subject to change without notice and revision of this document. For browser-based versions of this data sheet, refer to the left-hand navigation. 32 Submit Documentation Feedback Copyright © 1998–2019, Texas Instruments Incorporated Product Folder Links: LM2588 PACKAGE OPTION ADDENDUM www.ti.com 30-Sep-2021 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan (2) Lead finish/ Ball material MSL Peak Temp Op Temp (°C) Device Marking (3) (4/5) (6) LM2588S-12/NOPB ACTIVE DDPAK/ TO-263 KTW 7 45 RoHS-Exempt & Green SN Level-3-245C-168 HR -40 to 125 LM2588S -12 P+ LM2588S-3.3/NOPB ACTIVE DDPAK/ TO-263 KTW 7 45 RoHS-Exempt & Green SN Level-3-245C-168 HR -40 to 125 LM2588S -3.3 P+ LM2588S-5.0/NOPB ACTIVE DDPAK/ TO-263 KTW 7 45 RoHS-Exempt & Green SN Level-3-245C-168 HR -40 to 125 LM2588S -5.0 P+ LM2588S-ADJ NRND DDPAK/ TO-263 KTW 7 45 Non-RoHS & Green Call TI Level-3-235C-168 HR -40 to 125 LM2588S -ADJ P+ LM2588S-ADJ/NOPB ACTIVE DDPAK/ TO-263 KTW 7 45 RoHS-Exempt & Green SN Level-3-245C-168 HR -40 to 125 LM2588S -ADJ P+ LM2588SX-12/NOPB ACTIVE DDPAK/ TO-263 KTW 7 500 RoHS-Exempt & Green SN Level-3-245C-168 HR -40 to 125 LM2588S -12 P+ LM2588SX-3.3/NOPB ACTIVE DDPAK/ TO-263 KTW 7 500 RoHS-Exempt & Green SN Level-3-245C-168 HR -40 to 125 LM2588S -3.3 P+ LM2588SX-5.0/NOPB ACTIVE DDPAK/ TO-263 KTW 7 500 RoHS-Exempt & Green SN Level-3-245C-168 HR -40 to 125 LM2588S -5.0 P+ LM2588SX-ADJ/NOPB ACTIVE DDPAK/ TO-263 KTW 7 500 RoHS-Exempt & Green SN Level-3-245C-168 HR -40 to 125 LM2588S -ADJ P+ LM2588T-3.3/NOPB ACTIVE TO-220 NDZ 7 45 RoHS-Exempt & Green SN Level-1-NA-UNLIM -40 to 125 LM2588T -3.3 P+ LM2588T-5.0/NOPB ACTIVE TO-220 NDZ 7 45 RoHS-Exempt & Green SN Level-1-NA-UNLIM -40 to 125 LM2588T -5.0 P+ LM2588T-ADJ/NOPB ACTIVE TO-220 NDZ 7 45 RoHS-Exempt & Green SN Level-1-NA-UNLIM -40 to 125 LM2588T -ADJ P+ (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". Addendum-Page 1 Samples PACKAGE OPTION ADDENDUM www.ti.com 30-Sep-2021 RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of
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