SNVS506J May   2008  – December 2015 LM3691

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Voltage Options
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Circuit Operation
      2. 8.3.2 PWM Operation
        1. 8.3.2.1 Internal Synchronous Rectification
        2. 8.3.2.2 Current Limiting
      3. 8.3.3 ECO Operation
      4. 8.3.4 Soft-Start
      5. 8.3.5 Thermal Shutdown Protection
      6. 8.3.6 Overtemperature Maximum Load
    4. 8.4 Device Functional Modes
      1. 8.4.1 Forced PWM Mode
      2. 8.4.2 Shutdown Mode
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Inductor Selection
        2. 9.2.2.2 Input Capacitor Selection
        3. 9.2.2.3 Output Capacitor Selection
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
    3. 11.3 DSBGA Package Assembly and Use
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Community Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

7 Specifications

7.1 Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted)(1)(2)
MIN MAX UNIT
VIN pin to GND −0.2 6 V
EN, MODE, FB, SW pins (GND − 0.2) VIN + 0.2 V
Junction temperature (TJ-MAX) 150 °C
Continuous power dissipation(3) Internally Limited
Maximum lead temperature (soldering, 10 seconds) 260 °C
Storage temperature, Tstg 150 °C
(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
(2) If Military/Aerospace specified devices are required, contact the TI Sales Office/Distributors for availability and specifications.
(3) Internal thermal shutdown circuitry protects the device from permanent damage. Thermal shutdown engages at TJ = 150°C (typical) and disengages at TJ = 130°C (typical).

7.2 ESD Ratings

VALUE UNIT
V(ESD) Electrostatic discharge Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) ±2000 V
Machine model ±200
(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.

7.3 Recommended Operating Conditions

over operating free-air temperature range (unless otherwise noted)
MIN NOM MAX UNIT
Input voltage 2.3 5.5 V
Recommended load current 0 1000 mA
Junction temperature, TJ −30 125 °C
Ambient temperature, TA(1) −30 85 °C
(1) In applications where high power dissipation and/or poor package resistance is present, the maximum ambient temperature may have to be derated. Maximum ambient temperature (TA-MAX) is dependent on the maximum operating junction temperature (TJ-MAX), the maximum power dissipation of the device in the application (PD-MAX) and the junction to ambient thermal resistance of the package (RθJA) in the application, as given by the following equation: TA-MAX = TJ-MAX − (RθJA × PD-MAX). Due to the pulsed nature of testing the part, the temp in Electrical Characteristics is specified as TA = TJ.

7.4 Thermal Information

THERMAL METRIC(1) LM3691 UNIT
YZR (DSBGA)
6 PINS
RθJA Junction-to-ambient thermal resistance(2) 85 °C/W
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report, SPRA953.
(2) Junction-to-ambient thermal resistance is highly application and board layout dependent. In applications where high power dissipation exists, special care must be given to thermal dissipation issues in board design.

7.5 Electrical Characteristics

Unless otherwise specified, specifications apply to the LM3691 open-loop Typical Application Circuit with VIN = EN = 3.6 V; typical limits are for TA = 25°C and minimum and maximum limits apply over the operating ambient temperature range (−30°C ≤ TA = TJ ≤ +85°C).(1)(2)(3)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
VFB Feedback voltage PWM mode
no load VOUT = 1.1 V to 3.3 V		 –1% 1%
PWM mode
no load VOUT = 0.75 V to 1 V		 –10 10 mV
ISHDN Shutdown supply current EN = 0 V 0.03 1 µA
IQ_ECO ECO mode IQ ECO mode 64 80 µA
IQ_PWM PWM mode IQ PWM mode 490 600 µA
RDSON (P) Pin-pin resistance for PFET VIN = VGS = 3.6 V, IO = 200 mA 160 250 mΩ
RDSON (N) Pin-pin resistance for NFET VIN = VGS = 3.6 V, IO = −200 mA 115 180 mΩ
ILIM Switch peak current limit Open loop 1250 1500 1700 mA
VIH Logic high input 1.2 V
VIL Logic low input 0.4 V
IEN,MODE Input current 0.01 1 µA
FSW Switching frequency PWM mode 3.6 4 4.4 MHz
VON UVLO threshold(4) VIN rising, TA = 25°C 2.2 2.29 V
VIN falling 2.1 V
TSTARTUP Start time(5) TA = 25°C 70 145 300 µs
(1) All voltages are with respect to the potential at the GND pin.
(2) Minimum and maximum limits are specified by design, test or statistical analysis. Typical numbers represent the most likely norm.
(3) The parameters in the electrical characteristic table are tested under open-loop conditions at VIN = 3.6 V unless otherwise specified. For performance over the input voltage range and closed loop condition, refer to the datasheet curves.
(4) The UVLO rising threshold minus the falling threshold is always positive.
(5) Specified by design. Not production tested.

7.6 Typical Characteristics

LM3691TL Typical Application Circuit, VIN = 3.6 V, VOUT = 1.8 V, TA = 25°C, L = 1 μH, 2520, (LQM2HP1R0), CIN = COUT = 4.7 μF, 0603(1608), 6.3 V, (C1608X5R0J475K) unless otherwise noted.
LM3691 30013455.png
Figure 1. Quiescent Supply Current vs Supply Voltage No Switching, ECO Mode
LM3691 30013457.png
VOUT = 1.8 V
Figure 3. Shutdown Current vs Temperature
LM3691 30013459.png
VOUT = 0.75 V
Figure 5. Output Voltage vs Supply Voltage
LM3691 30013461.png
VOUT = 0.75 V
Figure 7. Output Voltage vs Output Current
LM3691 30013463.png
VOUT = 0.75 V
Figure 9. Input Current vs Output Current
LM3691 30013465.png
VOUT = 0.75 V
Figure 11. Efficiency vs, Output Current, ECO Mode
LM3691 30013443.gif
VOUT = 2.5 V
Figure 13. Efficiency vs Output Current, ECO Mode
LM3691 30013468.png
VOUT = 1.8 V
Figure 15. Efficiency vs Output Current, FPWM Mode
LM3691 30013469.png
VOUT = 0.75 V
Figure 17. Load Current Threshold vs Supply Voltage, ECO Mode to PWM Mode
LM3691 30013471.png
VOUT = 0.75 V
Figure 19. Output Voltage Ripple vs Supply Voltage
LM3691 30013473.png
VOUT = 0.75 V
Figure 21. Closed Loop Current Limit vs Temperature
LM3691 30013475.png
VOUT = 0.75 V
Figure 23. Line Transient Reponse, PWM Mode
LM3691 30013479.png
VOUT = 0.75 V ECO Mode 1 mA to 25 mA
Figure 25. Load Transient Reponse
LM3691 30013481.png
VOUT = 1.8 V ECO Mode 1 mA to 25 mA
Figure 27. Load Transient Reponse
LM3691 30013483.png
VOUT = 0.75 V ECO Mode to PWM Mode
Figure 29. Load Transient Reponse
LM3691 30013485.png
VOUT = 1.8 V ECO Mode to PWM Mode
Figure 31. Load Transient Reponse
LM3691 30013453.png
VOUT = 2.5 V ECO Mode to PWM Mode
Figure 33. Load Transient Reponse
LM3691 30013491.png
VOUT = 0.75 V PWM Mode
Figure 35. Load Transient Reponse
LM3691 30013446.png
VOUT = 2.5 V PWM Mode
Figure 37. Load Transient Reponse
LM3691 30013496.png
VOUT = 0.75 V ROUT = 2.5 Ω
Figure 39. Start-Up Into PWM Mode
LM3691 30013494.png
VOUT = 1.8 V ROUT = 6 Ω
Figure 41. Start-Up Into PWM Mode
LM3691 30013456.png
Figure 2. Quiescent Supply Current vs Supply Voltage No Switching, PWM Mode
LM3691 30013458.png
VOUT = 1.8 V
Figure 4. Switching Frequency vs Temperature, PWM Mode
LM3691 30013460.png
VOUT = 1.8 V
Figure 6. Output Voltage vs Supply Voltage
LM3691 30013462.png
VOUT = 1.8 V
Figure 8. Output Voltage vs Output Current
LM3691 30013464.png
VOUT = 1.8 V
Figure 10. Input Current vs Output Current
LM3691 30013466.gif
VOUT = 1.8 V
Figure 12. Efficiency vs Output Current, ECO Mode
LM3691 30013467.png
VOUT = 0.75 V
Figure 14. Efficiency vs Output Current, FPWM Mode
LM3691 300134a0.gif
VOUT = 2.5 V
Figure 16. Efficiency vs Output Current, FPWM Mode
LM3691 30013470.png
VOUT = 1.8 V
Figure 18. Load Current Threshold vs Supply Voltage, ECO Mode to PWM Mode
LM3691 30013472.png
VOUT = 1.8 V
Figure 20. Output Voltage Ripple vs Supply Voltage
LM3691 30013474.png
VOUT = 1.8 V
Figure 22. Closed Loop Current Limit vs Temperature
LM3691 30013478.png
VOUT = 1.8 V
Figure 24. Line Transient Reponse, PWM Mode
LM3691 30013480.png
VOUT = 0.75 V ECO Mode 25 mA to 1 mA
Figure 26. Load Transient Reponse
LM3691 30013482.png
VOUT = 1.8 V ECO Mode 25 mA to 1 mA
Figure 28. Load Transient Reponse
LM3691 30013484.png
VOUT = 0.75 V PWM Mode to ECO Mode
Figure 30. Load Transient Reponse
LM3691 30013452.png
VOUT = 2.5 V ECO Mode to PWM Mode
Figure 32. Load Transient Response
LM3691 30013490.png
VOUT = 1.8 V FPWM Mode
Figure 34. Load Transient Reponse
LM3691 30013492.png
VOUT = 1.8 V PWM Mode
Figure 36. Load Transient Reponse
LM3691 30013495.png
VOUT = 0.75 V ROUT = 750 Ω
Figure 38. Start-Up Into ECO Mode
LM3691 30013493.png
VOUT = 1.8 V ROUT = 1.8 kΩ
Figure 40. Start-Up Into ECO Mode