SNVSAR4A December   2016  – April 2017 LMR23610-Q1

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 Timing Characteristics
    7. 6.7 Switching Characteristics
    8. 6.8 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 Fixed Frequency Peak Current Mode Control
      2. 7.3.2 Adjustable Output Voltage
      3. 7.3.3 Enable/Sync
      4. 7.3.4 VCC, UVLO
      5. 7.3.5 Minimum ON-time, Minimum OFF-time and Frequency Foldback at Drop-out Conditions
      6. 7.3.6 Internal Compensation and CFF
      7. 7.3.7 Bootstrap Voltage (BOOT)
      8. 7.3.8 Over Current and Short Circuit Protection
      9. 7.3.9 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
      2. 7.4.2 Active Mode
      3. 7.4.3 CCM Mode
      4. 7.4.4 Light Load Operation
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1  Custom Design With WEBENCH® Tools
        2. 8.2.2.2  Output Voltage Set-Point
        3. 8.2.2.3  Switching Frequency
        4. 8.2.2.4  Inductor Selection
        5. 8.2.2.5  Output Capacitor Selection
        6. 8.2.2.6  Feed-Forward Capacitor
        7. 8.2.2.7  Input Capacitor Selection
        8. 8.2.2.8  Bootstrap Capacitor Selection
        9. 8.2.2.9  VCC Capacitor Selection
        10. 8.2.2.10 Under Voltage Lockout Set-Point
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Compact Layout for EMI Reduction
    3. 10.3 Ground Plane and Thermal Considerations
    4. 10.4 Feedback Resistors
    5. 10.5 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Custom Design With WEBENCH® Tools
    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

6 Specifications

6.1 Absolute Maximum Ratings

Over the recommended operating junction temperature range of -40 °C to 125 °C (unless otherwise noted) (1)
PARAMETER MIN MAX UNIT
Input Voltages VIN to PGND -0.3 42 V
EN/SYNC to AGND -5.5 VIN + 0.3
FB to AGND -0.3 4.5
AGND to PGND -0.3 0.3
Output Voltages SW to PGND -1 VIN + 0.3 V
SW to PGND less than 10 ns transients -5 42
BOOT to SW -0.3 5.5
VCC to AGND -0.3 4.5 (2)
TJ Junction temperature -40 150 °C
Tstg Storage temperature -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) In shutdown mode, the VCC to AGND maximum value is 5.25 V.

6.2 ESD Ratings

VALUE UNIT
V(ESD) Electrostatic discharge Human-body model (HBM) (1) ±2000 V
Charged-device model (CDM) ±1000
(1) AEC Q100-002 indicates that HBM stressing shall be in accordance with the ANSI/ESDA/JEDEC JS-001 specification.

6.3 Recommended Operating Conditions

Over the recommended operating junction temperature range of -40 °C to 125 °C (unless otherwise noted) (1)
MIN MAX UNIT
Input Voltage VIN 4 36 V
EN/SYNC -5 36
FB -0.3 1.2
Output Voltage VOUT 1 28 V
Output Current IOUT 0 1 A
Temperature Operating junction temperature, TJ -40 125 °C
(1) Operating Ratings indicate conditions for which the device is intended to be functional, but do not guarantee specific performance limits. For guaranteed specifications, see Electrical Characteristics.

6.4 Thermal Information

THERMAL METRIC (1) (2) DDA (8 PINS) UNIT
RθJA Junction-to-ambient thermal resistance 42.0 °C/W
ψJT Junction-to-top characterization parameter 5.9
ψJB Junction-to-board characterization parameter 23.4
RθJC(top) Junction-to-case (top) thermal resistance 45.8
RθJC(bot) Junction-to-case (bottom) thermal resistance 3.6
RθJB Junction-to-board thermal resistance 23.4
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report, SPRA953.
(2) Power rating at a specific ambient temperature TA should be determined with a maximum junction temperature (TJ) of 125 °C, which is illustrated in Recommended Operating Conditions section.

6.5 Electrical Characteristics

Limits apply over the recommended operating junction temperature (TJ) range of -40 °C to +125 °C, unless otherwise stated. Minimum and Maximum limits are specified through test, design or statistical correlation. Typical values represent the most likely parametric norm at TJ = 25 °C, and are provided for reference purposes only.
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
POWER SUPPLY (VIN PIN)
VIN Operation input voltage 4 36 V
VIN_UVLO Under voltage lockout thresholds Rising threshold 3.3 3.7 3.9 V
Falling threshold 2.9 3.3 3.5
ISHDN Shutdown supply current VEN = 0 V, VIN = 12 V, TJ = -40 °C to 125 °C 2.0 4.0 μA
IQ Operating quiescent current (non- switching) VIN =12 V, VFB = 1.1 V, TJ = -40 °C to 125 °C, PFM mode 75 μA
ENABLE (EN PIN)
VEN_H Enable rising threshold Voltage 1.4 1.55 1.7 V
VEN_HYS Enable hysteresis voltage 0.4 V
VWAKE Wake-up threshold 0.4 V
IEN Input leakage current at EN pin VIN = 4 V to 36 V, VEN= 2 V 10 100 nA
VIN = 4 V to 36 V, VEN= 36 V 1 μA
VOLTAGE REFERENCE (FB PIN)
VREF Reference voltage VIN = 4 V to 36 V, TJ = 25 °C 0.985 1.0 1.015 V
VIN = 4 V to 36 V, TJ = -40 °C to 125 °C 0.980 1.0 1.020
ILKG_FB Input leakage current at FB pin VFB= 1 V 10 nA
INTERNAL LDO (VCC PIN)
VCC Internal LDO output voltage 4.1 V
VCC_UVLO VCC under voltage lockout thresholds Rising threshold 2.8 3.2 3.6 V
Falling threshold 2.4 2.8 3.2
CURRENT LIMIT
IHS_LIMIT Peak inductor current limit 1.4 2.0 2.6 A
ILS_LIMIT Valley inductor current limit 1.0 1.5 2.1 A
IL_ZC Zero cross current limit -0.04 A
INTEGRATED MOSFETS
RDS_ON_HS High-side MOSFET ON-resistance VIN = 12 V, IOUT = 1 A 185 mΩ
RDS_ON_LS Low-side MOSFET ON-resistance VIN = 12 V, IOUT = 1 A 105 mΩ
THERMAL SHUTDOWN
TSHDN Thermal shutdown threshold 162 170 178 °C
THYS Hysteresis 15 °C

6.6 Timing Characteristics

Over the recommended operating junction temperature range of -40 °C to 125 °C (unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
HICCUP MODE
NOC(1) Number of cycles that LS current limit is tripped to enter Hiccup mode 64 Cycles
TOC Hiccup retry delay time 5 ms
SOFT START
TSS Internal soft-start time   The time of internal reference to increase from 0 V to 1.0 V 1 2 3 ms
(1) Guaranteed by design.

6.7 Switching Characteristics

Over the recommended operating junction temperature range of -40 °C to 125 °C (unless otherwise noted)
PARAMETER MIN TYP MAX UNIT
SW (SW PIN)
fSW Default switching frequency 340 400 460 kHz
TON_MIN Minimum turn-on time 60 90 ns
TOFF_MIN(1) Minimum turn-off time 100 ns
SYNC (EN/SYNC PIN)
fSYNC SYNC frequency range 200 2200 kHz
VSYNC Amplitude of SYNC clock AC signal (measured at SYNC pin) 2.8 5.5 V
TSYNC_MIN Minimum sync clock ON and OFF time 100 ns
(1) Guaranteed by design.

6.8 Typical Characteristics

Unless otherwise specified the following conditions apply: VIN = 12 V, fSW = 400 kHz, L = 22 µH, COUT = 47 µF × 2, TA = 25°C.
LMR23610-Q1 D001_SNVSAH4.gif
fSW = 400 kHz VOUT = 5 V
Figure 1. Efficiency vs. Load Current
LMR23610-Q1 D003_SNVSAH4.gif
fSW = 1000 kHz (Sync) VOUT = 5 V
Figure 3. Efficiency vs. Load Current
LMR23610-Q1 D005_SNVSAH4.gif
VOUT = 5 V
Figure 5. Load Regulation
LMR23610-Q1 D007_SNVSAH4.gif
VOUT = 5 V
Figure 7. Dropout Curve
LMR23610-Q1 D009_SNVSAH2.gif
VIN = 12 V VFB = 1.1 V
Figure 9. IQ vs. Junction Temperature
LMR23610-Q1 D011_SNVSAH2.gif
Figure 11. VIN UVLO Hysteresis vs. Junction Temperature
LMR23610-Q1 D002_SNVSAH4.gif
fSW = 400 kHz VOUT = 3.3 V
Figure 2. Efficiency vs. Load Current
LMR23610-Q1 D004_SNVSAH4.gif
fSW = 1000 kHz (Sync) VOUT = 3.3 V
Figure 4. Efficiency vs. Load Current
LMR23610-Q1 D006_SNVSAH4.gif
VOUT = 5 V
Figure 6. Line Regulation
LMR23610-Q1 D008_SNVSAH4.gif
VOUT = 3.3 V
Figure 8. Dropout Curve
LMR23610-Q1 D010_SNVSAH2.gif
Figure 10. VIN UVLO Rising Threshold vs. Junction Temperature
LMR23610-Q1 D009_SNVSAH4.gif
VIN = 12 V
Figure 12. HS & LS Current Limit vs. Junction Temperature