SNVS089P July   2000  – September 2026 LM3488

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings: LM3488
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Slope Compensation Ramp
      2. 6.3.2 Frequency Adjust, Synchronization, Shutdown
      3. 6.3.3 Short-Circuit Protection
    4. 6.4 Device Functional Modes
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Applications
      1. 7.2.1 Boost Converter
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
          1. 7.2.1.2.1 Custom Design With WEBENCH® Tools
          2. 7.2.1.2.2 Power Inductor Selection
          3. 7.2.1.2.3 Programming the Output Voltage
          4. 7.2.1.2.4 Setting the Current Limit
          5. 7.2.1.2.5 Current Limit With External Slope Compensation
          6. 7.2.1.2.6 Power Diode Selection
          7. 7.2.1.2.7 Power MOSFET Selection
          8. 7.2.1.2.8 Input Capacitor Selection
          9. 7.2.1.2.9 Output Capacitor Selection
        3. 7.2.1.3 Application Curve
      2. 7.2.2 Designing SEPIC Using LM3488
        1. 7.2.2.1 Design Requirements
        2. 7.2.2.2 Detailed Design Procedure
          1. 7.2.2.2.1 Power MOSFET Selection
          2. 7.2.2.2.2 Power Diode Selection
          3. 7.2.2.2.3 Selection Of Inductors L1 and L2
          4. 7.2.2.2.4 Sense Resistor Selection
          5. 7.2.2.2.5 SEPIC Capacitor Selection
          6. 7.2.2.2.6 Input Capacitor Selection
          7. 7.2.2.2.7 Output Capacitor Selection
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Development Support
        1. 8.1.1.1 Custom Design With WEBENCH® Tools
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 Receiving Notification of Documentation Updates
    4. 8.4 Support Resources
    5. 8.5 Trademarks
    6. 8.6 Electrostatic Discharge Caution
    7. 8.7 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

5.5 Electrical Characteristics

Unless otherwise specified, VIN = 12V, RFA = 40kΩ, TJ = 25°C
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
VFB Feedback Voltage VCOMP = 1.4V, 2.97 ≤ VIN ≤ 40V 1.2507 1.26 1.2753 V
VCOMP = 1.4V, 2.97 ≤ VIN ≤ 40V, −40°C ≤ TJ ≤ 125°C 1.24 1.28
ΔVLINE Feedback Voltage Line Regulation 2.97 ≤ VIN ≤ 40V 0.001 %/V
ΔVLOAD Output Voltage Load Regulation IEAO Source/Sink ±0.5 %/A
VUVLO Input Undervoltage Lock-out 2.85 V
−40°C ≤ TJ ≤ 125°C 2.97
VUV(HYS) Input Undervoltage Lock-out Hysteresis 170 mV
−40°C ≤ TJ ≤ 125°C 130 210
Fnom Nominal Switching Frequency RFA = 40KΩ 400 kHz
RFA = 40KΩ, −40°C ≤ TJ ≤ 125°C 360 430
RDS1 (ON) Driver Switch On Resistance (top) IDR = 0.2A, VIN= 5V 16 Ω
RDS2 (ON) Driver Switch On Resistance (bottom) IDR = 0.2A 4.5 Ω
VDR (max) Maximum Drive Voltage Swing(1) VIN < 7.2V VIN V
VIN ≥ 7.2V 7.2
Dmax Maximum Duty Cycle(2) 100%
Tmin (on) Minimum On Time 325 nsec
−40°C ≤ TJ ≤ 125°C 230 550
ISUPPLY Supply Current (switching) See (3) 2.7 mA
See (3), −40°C ≤ TJ ≤ 125°C 3.0
IQ Quiescent Current in Shutdown Mode VFA/SYNC/SD = 5V(4), VIN = 5V 5 µA
VFA/SYNC/SD = 5V(4), VIN = 5V, −40°C ≤ TJ ≤ 125°C 7
VSENSE Current Sense Threshold Voltage VIN = 5V 135 156 180 mV
VIN = 5V, −40°C ≤ TJ ≤ 125°C 125 190
VSC Short-Circuit Current Limit Sense Voltage VIN = 5V 343 mV
VIN = 5V, −40°C ≤ TJ ≤ 125°C 250 415
VSL Internal Compensation Ramp Voltage VIN = 5V 92 mV
VIN = 5V, −40°C ≤ TJ ≤ 125°C 52 132
VSL ratio VSL/VSENSE 0.30 0.49 0.70
VOVP Output Overvoltage Protection (with respect to feedback voltage) (5) VCOMP = 1.4V 32 50 78 mV
VCOMP = 1.4V, −40°C ≤ TJ ≤ 125°C 25 85
VOVP(HYS) Output Over-Voltage Protection Hysteresis(5) VCOMP = 1.4V 60 mV
VCOMP = 1.4V, −40°C ≤ TJ ≤ 125°C 20 110
Gm Error Ampifier Transconductance VCOMP = 1.4V, IEAO = 100µA (Source/Sink) 600 800 1000 µmho
VCOMP = 1.4V, IEAO = 100µA (Source/Sink), −40°C ≤ TJ ≤ 125°C 365 1265
AVOL Error Amplifier Voltage Gain VCOMP = 1.4V, IEAO = 100µA (Source/Sink) 38 V/V
VCOMP = 1.4V, IEAO = 100µA (Source/Sink), −40°C ≤ TJ ≤ 125°C 26 44
IEAO Error Amplifier Output Current (Source/ Sink) Source, VCOMP = 1.4V, VFB = 0V

 80 110 170 µA
Source, VCOMP = 1.4V, VFB = 0V, −40°C ≤ TJ ≤ 125°C

 50 220
Sink, VCOMP = 1.4V, VFB = 1.4V

 −70 −140 −180 µA
Sink, VCOMP = 1.4V, VFB = 1.4V, −40°C ≤ TJ ≤ 125°C

 −60 −185
VEAO Error Amplifier Output Voltage Swing Upper Limit: VFB = 0V, COMP Pin = Floating 2.2 V
Upper Limit: VFB = 0V, COMP Pin = Floating, −40°C ≤ TJ ≤ 125°C 1.8 2.4
Lower Limit: VFB = 1.4V 0.56 V
Lower Limit: VFB = 1.4V, −40°C ≤ TJ ≤ 125°C 0.2 1.0
TSS Internal Soft-Start Delay VFB = 1.2V, VCOMP = Floating 4 ms
Tr Drive Pin Rise Time Cgs = 3000pf, VDR = 0 to 3V 25 ns
Tf Drive Pin Fall Time Cgs = 3000pf, VDR = 0 to 3V 25 ns
VSD Shutdown and Synchronization signal threshold (6) Output = High 1.27 V
Output = High, −40°C ≤ TJ ≤ 125°C 1.4
Output = Low 0.65 V
Output = Low, −40°C ≤ TJ ≤ 125°C 0.3
ISD Shutdown Pin Current VSD = 5V −1 µA
VSD = 0V +1
IFB Feedback Pin Current 15 nA
TSD Thermal Shutdown 165 °C
Tsh Thermal Shutdown Hysteresis 10 °C
(1) The voltage on the drive pin, VDR is equal to the input voltage when input voltage is less than 7.2V. VDR is equal to 7.2V when the input voltage is greater than or equal to 7.2V.
(2) The limits for the maximum duty cycle can not be specified because the part does not permit less than 100% maximum duty cycle operation.
(3) For this test, the FA/SYNC/SD Pin is pulled to ground using a 40K resistor .
(4) For this test, the FA/SYNC/SD Pin is pulled to 5V using a 40K resistor.
(5) The over-voltage protection is specified with respect to the feedback voltage because the over-voltage protection tracks the feedback voltage. The over-voltage thresold can be calculated by adding the feedback voltage, VFB to the over-voltage protection specification.
(6) The FA/SYNC/SD pin should be pulled to VIN through a resistor to turn the regulator off.