SNVS115E April   2000  – June 2019 LM2587

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  ESDRatings
    3. 6.3  Recommended Operating Ratings
    4. 6.4  Thermal Information
    5. 6.5  Electrical Characteristics: 3.3 V
    6. 6.6  Electrical Characteristics: 5 V
    7. 6.7  Electrical Characteristics: 12 V
    8. 6.8  Electrical Characteristics: Adjustable
    9. 6.9  Electrical Characteristics: All Output Voltage Versions
    10. 6.10 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 Step-Up (Boost) Regulator Operation
  8. 8 Application And Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Typical Boost Regulator Applications
      2. 8.2.2 Typical Flyback Regulator Applications
        1. 8.2.2.1 Transformer Selection (T)
        2. 8.2.2.2 Transformer Footprints
          1. 8.2.2.2.0.1 T4
      3. 8.2.3 Design Requirements
      4. 8.2.4 Detailed Design Procedure
        1. 8.2.4.1 Custom Design With Webench® Tools
        2. 8.2.4.2 Programming Output Voltage (Selecting R1 And R2)
        3. 8.2.4.3 Short Circuit Condition
        4. 8.2.4.4 Flyback Regulator Input Capacitors
        5. 8.2.4.5 Switch Voltage Limits
        6. 8.2.4.6 Output Voltage Limitations
        7. 8.2.4.7 Noisy Input Line Condition)
        8. 8.2.4.8 Stability
    3. 8.3 Additional Application 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
      1. 9.3.1 European Magnetic Vendor Contacts
      2. 9.3.2 Coilcraft
      3. 9.3.3 Pulse Engineering
  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

6.9 Electrical Characteristics: All Output Voltage Versions (4)

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)
See(7) 		11 15.5/16.5 mA
ISWITCH = 3.0A 85 140/165 mA
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		 100 85/75 115/125 kHz
fSC Short-Circuit
Frequency		 Measured at Switch Pin
RLOAD = 100Ω
VFEEDBACK = 1.15V		 25 kHz
VEAO Error Amplifier
Output Swing		 Upper Limit
See(6) 		2.8 2.6/2.4 V
Lower Limit
See(7) 		0.25 0.40/0.55 V
IEAO Error Amp
Output Current
(Source or Sink)		 See(8) 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
D Maximum Duty Cycle RLOAD = 100Ω
See(6) 		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
(1) Note that switch current and output current are not identical in a step-up regulator. Output current cannot be internally limited when the LM2587 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 LM2587 is used as a flyback regulator (see the section for more information).
(2) 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.
(3) External components such as the diode, inductor, input and output capacitors can affect switching regulator performance. When the LM2587 is used as shown in Figure 61 and Figure 62, system performance will be as specified by the system parameters.
(4) 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.
(5) A 1-MΩ resistor is connected to the compensation pin (which is the error amplifier output) to ensure accuracy in measuring AVOL.
(6) 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. Adj: VFB = 1.05 V; 3.3 V: VFB = 2.81 V; 5 V: VFB = 4.25 V; 12 V: VFB = 10.2 V.
(7) 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. Adj: VFB = 1.41 V; 3.3 V: VFB = 3.8 V; 5 V: VFB = 5.75 V; 12 V: VFB = 13.8 V.
(8) To measure the worst-case error amplifier output current, the LM2587 is tested with the feedback voltage set to its low value (specified in Note 7) and at its high value (specified in Note 8).