SNVS483H January   2007  – August 2017 LM25574

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Application Schematic
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 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 High Voltage Start-Up Regulator
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown and Stand-by Mode
      2. 7.4.2 Oscillator and Sync Capability
      3. 7.4.3 Error Amplifier and PWM Comparator
      4. 7.4.4 Ramp Generator
      5. 7.4.5 Maximum Duty Cycle and Input Drop-out Voltage
      6. 7.4.6 Current Limit
      7. 7.4.7 Soft-Start
      8. 7.4.8 Boost Pin
      9. 7.4.9 Thermal Protection
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1  External Components
      2. 8.1.2  R3 (RT)
      3. 8.1.3  L1
      4. 8.1.4  C3 (CRAMP)
      5. 8.1.5  C9
      6. 8.1.6  C1
      7. 8.1.7  C8
      8. 8.1.8  C7
      9. 8.1.9  C4
      10. 8.1.10 R5, R6
      11. 8.1.11 R1, R2, C2
      12. 8.1.12 R4, C5, C6
      13. 8.1.13 Bias Power Dissipation Reduction
    2. 8.2 Typical Application
      1. 8.2.1 Typical Schematic for High Frequency (1MHz) Application
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Custom Design With WEBENCH® Tools
  9. 9 Layout
    1. 9.1 Layout Guidelines
      1. 9.1.1 PCB Layout and Thermal Considerations
    2. 9.2 Layout Example
  10. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Developmental Support
        1. 10.1.1.1 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

6.5 Electrical Characteristics

at TJ = 25°C, and VIN = 24 V, RT = 32.4 kΩ (unless otherwise noted).(1)
PARAMETERTEST CONDITIONSMINTYPMAXUNIT
STARTUP REGULATOR
VccReg Vcc Regulator Output TJ = –40°C to +125°C 6.85 7.15 7.45 V
Vcc LDO Mode turn-off 9 V
Vcc Current Limit Vcc = 0 V 25 mA
VCC SUPPLY
Vcc UVLO Threshold (Vcc increasing) TJ = –40°C to +125°C 5.03 5.35 5.67 V
Vcc Undervoltage Hysteresis 0.35 V
Bias Current (Iin) FB = 1.3 V TJ = –40°C to +125°C 3.7 4.5 mA
Shutdown Current (Iin) SD = 0 V TJ = –40°C to +125°C 48 70 µA
SHUTDOWN THRESHOLDS
Shutdown Threshold (SD Increasing) TJ = –40°C to +125°C 0.47 0.7 0.9 V
Shutdown Hysteresis 0.1 V
Standby Threshold (Standby Increasing) TJ = –40°C to +125°C 1.17 1.225 1.28 V
Standby Hysteresis 0.1 V
SD Pull-up Current Source 5 µA
SWITCH CHARACTERSICS
Buck Switch Rds(on) TJ = –40°C to +125°C 750 1500 mΩ
BOOST UVLO 4 V
BOOST UVLO Hysteresis 0.56 V
Pre-charge Switch Rds(on) 70 Ω
Pre-charge Switch on-time 250 ns
CURRENT LIMIT
Cycle by Cycle Current Limit RAMP = 0 V TJ = –40°C to +125°C 0.6 0.7 0.8 A
Cycle by Cycle Current Limit Delay RAMP = 2.5 V 75 ns
SOFT-START
SS Current Source TJ = –40°C to +125°C 7 10 14 µA
OSCILLATOR
Frequency1 TJ = –40°C to +125°C 180 200 220 kHz
Frequency2 RT = 11 kΩ TJ = –40°C to +125°C 425 485 545 kHz
SYNC Source Impedance 11 kΩ
SYNC Sink Impedance 110 Ω
SYNC Threshold (falling) 1.3 V
SYNC Frequency RT = 11 kΩ TJ = –40°C to +125°C 550 kHz
SYNC Pulse Width Minimum TJ = –40°C to +125°C 15 ns
RAMP GENERATOR
Ramp Current 1 Vin = 36 V,
Vout=10 V		 TJ = –40°C to +125°C 272 310 368 µA
Ramp Current 2 Vin = 10 V,
Vout=10 V		 TJ = –40°C to +125°C 36 50 64 µA
PWM COMPARATOR
Forced Off-time TJ = –40°C to +125°C 416 500 575 ns
Min On-time 80 ns
COMP to PWM Comparator Offset 0.7 V
ERROR AMPLIFIER
Feedback Voltage Vfb = COMP TJ = –40°C to +125°C 1.207 1.225 1.243 V
FB Bias Current 17 nA
DC Gain 70 dB
COMP Sink / Source Current TJ = –40°C to +125°C 3 mA
Unity Gain Bandwidth 3 MHz
DIODE SENSE RESISTANCE
DSENSE 250 mΩ
THERMAL SHUTDOWN
Tsd Thermal Shutdown Threshold 165 °C
Thermal Shutdown Hysteresis 25 °C
(1) Min and Max limits are 100% production tested at 25°C. Limits over the operating temperature range are assured through correlation using Statistical Quality Control (SQC) methods. Limits are used to calculate Texas Instruments' Average Outgoing Quality Level (AOQL).