SNVS117E April   1998  – June 2019 LM2588

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Typical Applications
  3. 3 Description
    1.     Device Images
      1.      Flyback Regulator
  4. 4 Revision History
  5. 5 Pin Configurations
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Ratings
    4. 6.4 Electrical Characteristics: 3.3 V
    5. 6.5 Electrical Characteristics: 5 V
    6. 6.6 Electrical Characteristics: 12 V
    7. 6.7 Electrical Characteristics: Adjustable
    8. 6.8 Electrical Characteristics: All Output Voltage Versions
    9. 6.9 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Flyback Regulator Operation
      2. 7.3.2 Step-Up (Boost) Regulator Operation
      3. 7.3.3 Shutdown Control
      4. 7.3.4 Frequency Adjustment
      5. 7.3.5 Frequency Synchronization
      6. 7.3.6 Programming Output Voltage (Selecting R1 And R2)
      7. 7.3.7 Short-Circuit Condition
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Typical Flyback Regulator Applications
        1. 8.2.1.1 Design Requirements
          1. 8.2.1.1.1 Transformer Selection (T)
          2. 8.2.1.1.2 Transformer Footprints
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Custom Design With WEBENCH® Tools
          2. 8.2.1.2.2 Flyback Regulator Input Capacitors
          3. 8.2.1.2.3 Switch Voltage Limits
          4. 8.2.1.2.4 Output Voltage Limitations
          5. 8.2.1.2.5 Noisy Input Line Condition
          6. 8.2.1.2.6 Stability
      2. 8.2.2 Typical Boost Regulator Applications
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
    3. 8.3 System Examples
      1. 8.3.1 Test Circuits
  9. 9 Layout
    1. 9.1 Layout Guidelines
    2. 9.2 Layout Example
    3. 9.3 Heat Sink/Thermal Considerations
  10. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Third-Party Products Disclaimer
      2. 10.1.2 Development Support
        1. 10.1.2.1 Custom Design With WEBENCH® Tools
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Community Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  11. 11Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

6.8 Electrical Characteristics: All Output Voltage Versions (5)

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
IS Input Supply Current Switch Off(8) 11 15.5/16.5 mA
ISWITCH = 3.0A 85 140/165 mA
IS/D Shutdown Input
Supply Current		 VSH = 3V 16 100/300 μA
VUV Input Supply
Undervoltage Lockout		 RLOAD = 100Ω 3.30 3.05 3.75 V
fO Oscillator Frequency Measured at Switch Pin
RLOAD = 100Ω, VCOMP = 1.0V
Freq. Adj. Pin Open (Pin 1)		 100 85/75 115/125 kHz
RSET = 22 kΩ 200 kHz
fSC Short-Circuit Frequency Measured at Switch Pin
RLOAD = 100Ω
VFEEDBACK = 1.15V
25 kHz
VEAO Error Amplifier Output Swing Upper Limit(7) 2.8 2.6/2.4 V
Lower Limit(8) 0.25 0.40/0.55 V
IEAO Error Amp Output Current (Source or Sink) See(9) 165 110/70 260/320 μA
ISS Soft Start Current VFEEDBACK = 0.92V
VCOMP = 1.0V		 11.0 8.0/7.0 17.0/19.0 μA
DMAX Maximum Duty Cycle RLOAD = 100Ω(7) 98 93/90 %
IL Switch Leakage Current Switch Off
VSWITCH = 60V		 15 300/600 μA
VSUS Switch Sustaining Voltage dV/dT = 1.5V/ns 65 V
VSAT Switch Saturation Voltage ISWITCH = 5.0A 0.7 1.1/1.4 V
ICL NPN Switch Current Limit 6.5 5.0 9.5 A
VSTH Synchronization Threshold Voltage FSYNC = 200 kHz
VCOMP = 1V, VIN = 5V		 0.75 0.625/0.40 0.875/1.00 V
ISYNC Synchronization
Pin Current		 VIN = 5V
VCOMP = 1V, VSYNC = VSTH 		100 200 μA
VSHTH ON /OFF Pin (Pin 1) Threshold Voltage VCOMP = 1V(10) 1.6 1.0/0.8 2.2/2.4 V
ISH ON /OFF Pin (Pin 1) Current VCOMP = 1V
VSH = VSHTH 		40 15/10 65/75 μA
θJA
θJA
θJC 		Thermal Resistance NDZ Package, Junction to Ambient(11)
NDZ Package, Junction to Ambient(12)
NDZ Package, Junction to Case		 65
45
2		 °C/W
θJA
θJA
θJA
θJC 		KTW Package, Junction to Ambient(13)
KTW Package, Junction to Ambient(14)
KTW Package, Junction to Ambient(15)
KTW Package, Junction to Case		 56
35
26
2
(1) 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.
(2) 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).
(3) 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.
(4) 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.
(5) 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.
(6) A 1.0 MΩ resistor is connected to the compensation pin (which is the error amplifier output) to ensure accuracy in measuring AVOL.
(7) 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.
(8) 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.
(9) 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 table) and at its high value (specified in Note 2 under the Electrical Characteristics: All Output Voltage Versions table).
(10) 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).
(11) 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.
(12) 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.
(13) 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.
(14) 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.
(15) 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.