SNVS120G April   2000  – May 2019 LM2585

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      12-V Flyback Regulator Design Example
  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  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 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 T6
          2. 8.2.2.2.0.2 T6
      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
      5. 8.2.5 Application Curve
    3. 8.3 Additional Application Examples
      1. 8.3.1 Test Circuits
  9. 9 Layout
    1. 9.1 Layout Guidelines
    2. 9.2 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

6.9 Electrical Characteristics: All Versions

PARAMETER TEST CONDITIONS TYP MIN MAX UNIT
COMMON DEVICE PARAMETERS for all versions (2)
IS Input Supply Current (Switch Off)(5) 11 15.5/16.5 mA
ISWITCH = 1.8A 50 100/115 mA
VUV Input Supply
Undervoltage Lockout		 RLOAD = 100Ω 3.30 3.05 3.75 V
fO Oscillator Frequency Measured at Switch Pin
RLOAD = 100Ω 100 85/75 115/125 kHz
VCOMP = 1.0V
fSC Short-Circuit
Frequency		 Measured at Switch Pin
RLOAD = 100Ω 25 kHz
VFEEDBACK = 1.15V
VEAO Error Amplifier
Output Swing		 Upper Limit(4) 2.8 2.6/2.4 V
Lower Limit(5) 0.25 0.40/0.55 V
IEAO Error Amp
Output Current
(Source or Sink)		 See (6) 165 110/70 260/320 μA
ISS Soft Start Current VFEEDBACK = 0.92V 11.0 8.0/7.0 17.0/19.0 μA
VCOMP = 1.0V
D Maximum Duty
Cycle		 RLOAD = 100Ω(4) 98 93/90 %
IL Switch Leakage
Current		 Switch Off 15 300/600 μA
VSWITCH = 60V
VSUS Switch Sustaining
Voltage		 dV/dT = 1.5V/ns 65 V
VSAT Switch Saturation
Voltage		 ISWITCH = 3.0A 0.45 0.65/0.9 V
ICL NPN Switch
Current Limit		 4 3 7.0 A
(1) External components such as the diode, inductor, input and output capacitors can affect switching regulator performance. When the LM2585 is used as shown in Figure 47 and Figure 48, system performance will be as specified by the system parameters.
(2) 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.
(3) A 1-MΩ resistor is connected to the compensation pin (which is the error amplifier output) to ensure accuracy in measuring AVOL.
(4) 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.
(5) 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.
(6) To measure the worst-case error amplifier output current, the LM2585 is tested with the feedback voltage set to its low value (specified in Tablenote 3) and at its high value (specified in Tablenote 2).