SNOSB38C January   2009  – November 2017 LM3241

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and 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 System Characteristics
    7. 6.7 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 Circuit Operation
      2. 7.3.2 Internal Synchronization Rectification
      3. 7.3.3 Current Limiting
      4. 7.3.4 Dynamically Adjustable Output Voltage
      5. 7.3.5 Thermal Overload Protection
      6. 7.3.6 Soft Start
    4. 7.4 Device Functional Modes
      1. 7.4.1 PWM Mode Operation
      2. 7.4.2 Eco-mode™ Operation
      3. 7.4.3 Shutdown Mode
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Setting the Output Voltage
        2. 8.2.2.2 Inductor Selection
          1. 8.2.2.2.1 Method 1
          2. 8.2.2.2.2 Method 2
        3. 8.2.2.3 Capacitor Selection
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 DSBGA Package Assembly and Use
      2. 10.1.2 Board Layout Considerations
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

パッケージ・オプション

メカニカル・データ（パッケージ｜ピン）
サーマルパッド・メカニカル・データ
発注情報

6 Specifications

6.1 Absolute Maximum Ratings

See (1) and (2).
MIN MAX UNIT
Pin voltage VIN to GND –0.2 6 V
EN, FB, VCON, SW (GND − 0.2) (VIN + 0.2)(3)
Continuous power dissipation(4) Internally limited
Junction temperature, TJ-MAX 150 °C
Storage temperature, Tstg –65 150 °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) All voltages are with respect to the potential at the GND pins.
(3) All pins are limited to the 6-V maximum stated for the VIN supply.
(4) Internal thermal shutdown circuitry protects the device from permanent damage. Thermal shutdown engages at TJ = 150°C (typ.) and disengages at TJ = 125°C (typical).

6.2 ESD Ratings

VALUE UNIT
V(ESD) Electrostatic discharge Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1)(2) 2000 V
Charged-device model (CDM), per JEDEC specification JESD22-C101(3) 1250
(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
(2) The human body model is a 100-pF capacitor discharged through a 1.5-kΩ resistor into each pin. (MIL-STD-883 3015.7).
(3) JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.

6.3 Recommended Operating Conditions

See (1).
MIN NOM MAX UNIT
Input voltage 2.7 5.5 V
Recommended load current 0 750 mA
TJ Junction temperature –40 125 °C
TA Ambient temperature(2) –40 85 °C
(1) All voltages are with respect to the potential at the GND pins.
(2) In applications where high power dissipation and/or poor package thermal resistance is present, the maximum ambient temperature may have to be de-rated. Maximum ambient temperature (TA-MAX) is dependent on the maximum operating junction temperature (TJ-MAX-OP = 125°C), the maximum power dissipation of the device in the application (PD-MAX), and the junction-to ambient thermal resistance of the part/package in the application (RθJA), as given by the following equation: TA-MAX = TJ-MAX-OP – (RθJA × PD-MAX).

6.4 Thermal Information

THERMAL METRIC(1) LM3241 UNIT
YZR (DSBGA)
6 PINS
RθJA Junction-to-ambient thermal resistance 117 °C/W
RθJC(top) Junction-to-case (top) thermal resistance 1 °C/W
RθJB Junction-to-board thermal resistance 32.5 °C/W
ψJT Junction-to-top characterization parameter 0.2 °C/W
ψJB Junction-to-board characterization parameter 32.6 °C/W
RθJC(bot) Junction-to-case (bottom) thermal resistance — °C/W
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report.

6.5 Electrical Characteristics

All voltages are with respect to the potential at the GND pins. Minimum (MIN) and maximum (MAX) limits are specified by design, test, or statistical analysis. For performance over the input voltage range and closed-loop results, see the curves in the Typical Characteristics section.
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
VFB,MIN Feedback voltage at minimum setting PWM mode, VCON = 0.24 V 0.6 V
PWM mode, open loop conditions at VIN = 3.6 V, VCON = 0.24 V 0.58 0.62
VFB,MAX Feedback voltage at maximum setting PWM mode, VCON = 1.36 V, VIN = 3.9 V 3.4 V
PWM mode, open loop conditions at VIN = 3.6 V, VCON = 1.36 V, VIN = 3.9 V 3.332 3.468
ISHDN Shutdown supply current EN = SW = VCON = 0 V(1) 0.1 µA
open loop conditions at VIN = 3.6 V,
EN = SW = VCON = 0 V(1)		 2
IQ_PWM PWM mode quiescent current PWM mode, No switching(2), VCON = 0 V,
FB = 1 V		 620 µA
PWM mode, open loop conditions at VIN = 3.6 V, No switching(2), VCON = 0 V, FB = 1 V 750
IQ_ECO Eco-mode quiescent current Eco-mode, No switching(2),
VCON = 0.8 V, FB = 2.05 V		 45 µA
Eco-mode, open loop conditions at VIN = 3.6 V, No switching(2), VCON = 0.8 V, FB = 2.05 V 60
RDSON (P) Pin-pin resistance for PFET VIN = VGS = 3.6 V, ISW = 200 mA 160 mΩ
Open loop conditions at VIN = 3.6 V,
VIN = VGS = 3.6 V, ISW = 200 mA		 250
RDSON (N) Pin-pin resistance for NFET VIN = VGS = 3.6 V, ISW = −200 mA 110 mΩ
Open loop conditions at VIN = 3.6 V,
VIN = VGS = 3.6 V, ISW = −200 mA		 200
ILIM PFET switch peak current limit(3)   1450 mA
Open loop conditions at VIN = 3.6 V 1300 1600
FOSC Internal oscillator frequency 6 MHz
Open loop conditions at VIN = 3.6 V 5.7 6.3
VIH EN Logic high input threshold Open loop conditions at VIN = 3.6 V 1.2 V
VIL EN Logic low input threshold Open loop conditions at VIN = 3.6 V 0.4 V
Gain VCON to VOUT gain 0.24 V ≤ VCON ≤ 1.36 V 2.5 V/V
ICON VCON pin leakage current Open-loop mode, VCON = 1 V ±1 µA
(1) Shutdown current includes leakage current of PFET.
(2) IQ specified here is when the part is not switching under test mode conditions. For operating quiescent current at no load, see the curves in the Typical Characteristics section.
(3) Current limit is built-in, fixed, and not adjustable.

6.6 System Characteristics

The following spec table entries are specified by design providing the component values in Figure 29 are used. These parameters are not verified by production testing. Minimum (MIN) and maximum (MAX) values apply over the full operating ambient temperature range (–40°C ≤ TA ≤ 85°C) and over the VIN range of 2.7 V to 5.5 V unless otherwise specified. L = 0.47 µH, DCR = 50 mΩ, CIN = 10 µF, 6.3 V, 0603 (1608), COUT = 4.7 µF, 6.3 V, 0603 (1608).
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
TCON TR VOUT step rise time from 0.6 V to 3.4 V (to reach 3.26 V) VIN = 3.6 V, VCON = 0.24 V to 1.36 V,
VCON TR = 1 µs, RLOAD = 10 Ω,
–30°C ≤ TA ≤ 85°C		 25 µs
VIN = 3.6 V, VCON = 0.24 V to 1.36 V,
VCON TR = 1 µs, RLOAD = 10 Ω		 30
VOUT step fall time from 3.4 V to 0.6 V
(to reach 0.74 V)		 VIN = 3.6 V, VCON = 1.36 V to 0.24 V,
VCON TF = 1 µs, RLOAD = 10 Ω,
–30°C ≤ TA ≤ 85°C		 25
VIN = 3.6 V, VCON = 1.36 V to 0.24 V,
VCON TF = 1 µs, RLOAD = 10 Ω		 30
D Maximum Duty cycle 100%
IOUT Maximum output current capability 2.7 V ≤ VIN ≤ 5.5 V, 0.24 V ≤ VCON ≤ 1.36 V 750 mA
CCON VCON input capacitance VCON = 1 V, Test frequency = 100 KHz 5 10 pF
Linearity Linearity in control range 0.24 V to 1.36 V Monotronic in nature(1) –3% 3%
–50 +50 mV
TON Turnon time (time for output to reach 95% final value after Enable low-to-high transition) EN = Low-to-High, VIN = 4.2 V, VOUT = 3.4 V,
IOUT = < 1 mA, COUT = 4.7 µF, –30°C ≤ TA ≤ 85°C		 50 µs
EN = Low-to-High, VIN = 4.2 V, VOUT = 3.4 V,
IOUT = < 1 mA, COUT = 4.7 µF		 55
η Efficiency VIN = 3.6 V, VOUT = 0.8 V, IOUT = 10 mA,
Eco-mode		 75%
VIN = 3.6 V, VOUT = 1.8 V, IOUT = 200 mA,
PWM mode		 90%
VIN = 3.9 V, VOUT = 3.3 V, IOUT = 500 mA,
PWM mode		 95%
LINE TR Line transient response VIN = 3.6 V to 4.2 V, TR = TF = 10 µs,
IOUT = 100 mA, VOUT = 0.8 V		 50 mVpk
LOAD TR Load transient response VIN = 3.1 V/3.6 V/4.5 V, VOUT = 0.8 V,
IOUT = 50 mA to 150 mA, TR = TF = 0.1 µs		 50
(1) Linearity limits are ±3% or ±50 mV whichever is larger.

6.7 Typical Characteristics

VIN = EN = 3.6 V and TA = 25°C, unless otherwise noted.
LM3241 30090431.png
SW = VCON = EN = 0 V
Figure 1. Shutdown Current vs Temperature
LM3241 30090433.png
Closed loop Switching No load
Figure 3. Eco-mode Supply Current vs Output Voltage
LM3241 30090416.gif
VOUT = 2 V RLOAD = 10 Ω
Figure 5. Output Voltage vs Supply Voltage
LM3241 30090432.png
No switching FB = 1 V VCON = 0 V
Figure 2. Quiescent Current vs Supply Voltage
LM3241 30090434.png
VOUT = 2 V IOUT = 200 mA
Figure 4. Switching Frequency vs Temperature
LM3241 30090417.gif
VOUT = 3.4 V
Figure 6. Output Voltage vs Output Current
LM3241 30090422.gif
VOUT = 0.6 V
Figure 7. Output Voltage vs Output Current
LM3241 30090444.png
Figure 9. ECO-PWM Mode Threshold Current vs Output voltage
LM3241 30090439.png
VOUT = 2 V
Figure 11. Closed-loop Current Limit vs Temperature
LM3241 30090414.gif
VOUT = 3.3 V
Figure 13. Efficiency vs Output Current
LM3241 30090447.png
Figure 15. PFET RDSON vs Supply Voltage
LM3241 30090449.png
RLOAD = 10 Ω
Figure 17. Low VCON Voltage vs Output Voltage
LM3241 30090437.png
Figure 19. EN High Threshold vs Supply Voltage
LM3241 30090419.png
VOUT = 2 V IOUT = 50 mA
Figure 21. Output Voltage Ripple in Eco-Mode
LM3241 30090424.png
VOUT = 2.5 V IOUT = 10 mA/250 mA
Figure 23. Load Transient Response
LM3241 30090427.png
VIN = 4.2 V VOUT = 3.4 V RLOAD = 3.6 kΩ
Figure 25. Startup
LM3241 30090428.png
VOUT = 2 V RLOAD = 10 Ω
Figure 27. Timed Current Limit
LM3241 30090425.gif
VOUT = 2 V
Figure 8. Output Voltage vs Output Current
LM3241 30090445.png
Figure 10. PWM-Eco-Mode Threshold Current vs Output voltage
LM3241 30090413.gif
VOUT = 2 V
Figure 12. Efficiency vs Output Current
LM3241 30090415.gif
RLOAD = 10 Ω
Figure 14. Efficiency vs Output Voltage
LM3241 30090448.png
Figure 16. NFET RDSON vs Supply Voltage
LM3241 30090438.png
100% Duty Cycle
Figure 18. VIN-VOUT vs Output Current
LM3241 30090418.png
VOUT = 2 V IOUT = 200 mA
Figure 20. Output Voltage Ripple in PWM Mode
LM3241 30090423.png
VIN = 3.6 V/4.2 V VOUT = 0.8 V RLOAD = 8 Ω
Figure 22. Line Transient Response
LM3241 30090426.png
VOUT = 0.6 V IOUT = 10 mA/60 mA
Figure 24. Load Transient Response
LM3241 30090430.png
VIN = 4.2 V VOUT = 3.4 V RLOAD = 10 kΩ
Figure 26. Shutdown