SNVSB91C
July 2019 – June 2020
LMR36506-Q1
PRODUCTION DATA.
1
Features
2
Applications
3
Description
Device Images
Simplified Schematic
Efficiency versus Output Current VOUT = 3.3 V (Fixed), 2.2 MHz
4
Revision History
5
Device Comparison Table
6
Pin Configuration and Functions
Pin Functions
7
Specifications
7.1
Absolute Maximum Ratings
7.2
ESD (Automotive) Ratings
7.3
Recommended Operating Conditions
7.4
Thermal Information
7.5
Electrical Characteristics
7.6
Timing Characteristics
7.7
Switching Characteristics
7.8
System Characteristics
7.9
Typical Characteristics
8
Detailed Description
8.1
Overview
8.2
Functional Block Diagram
8.3
Feature Description
8.3.1
Enable, Start-up and Shutdown
8.3.2
External CLK SYNC (with MODE/SYNC)
8.3.2.1
Pulse-Dependent MODE/SYNC Pin Control
8.3.3
Adjustable Switching Frequency (with RT)
8.3.4
Power-Good Output Operation
8.3.5
Internal LDO, VCC UVLO, and VOUT/BIAS Input
8.3.6
Bootstrap Voltage and VCBOOT-UVLO (CBOOT Terminal)
8.3.7
Output Voltage Selection
8.3.8
Spread Spectrum
8.3.9
Soft Start and Recovery from Dropout
8.3.9.1
Recovery from Dropout
8.3.10
Current Limit and Short Circuit
8.3.11
Thermal Shutdown
8.3.12
Input Supply Current
8.4
Device Functional Modes
8.4.1
Shutdown Mode
8.4.2
Standby Mode
8.4.3
Active Mode
8.4.3.1
CCM Mode
8.4.3.2
Auto Mode - Light Load Operation
8.4.3.2.1
Diode Emulation
8.4.3.2.2
Frequency Reduction
8.4.3.3
FPWM Mode - Light Load Operation
8.4.3.4
Minimum On-time (High Input Voltage) Operation
8.4.3.5
Dropout
9
Application and Implementation
9.1
Application Information
9.2
Typical Application
9.2.1
Design Requirements
9.2.2
Detailed Design Procedure
9.2.2.1
Choosing the Switching Frequency
9.2.2.2
Setting the Output Voltage
9.2.2.2.1
FB for Adjustable Output
9.2.2.3
Inductor Selection
9.2.2.4
Output Capacitor Selection
9.2.2.5
Input Capacitor Selection
9.2.2.6
CBOOT
9.2.2.7
VCC
9.2.2.8
CFF Selection
9.2.2.8.1
External UVLO
9.2.2.9
Maximum Ambient Temperature
9.2.3
Application Curves
9.3
What to Do and What Not to Do
10
Power Supply Recommendations
11
Layout
11.1
Layout Guidelines
11.1.1
Ground and Thermal Considerations
11.2
Layout Example
12
Device and Documentation Support
12.1
Documentation Support
12.1.1
Related Documentation
12.2
Receiving Notification of Documentation Updates
12.3
Support Resources
12.4
Trademarks
12.5
Electrostatic Discharge Caution
12.6
Glossary
13
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
RPE|9
MPQF528A
Thermal pad, mechanical data (Package|Pins)
RPE|9
QFND681A
Orderable Information
snvsb91c_oa
snvsb91c_pm
7.9
Typical Characteristics
Unless otherwise specified, the following conditions apply: T
A
= 25°C, V
IN
= 13.5 V
V
OUT
= 3.3 V Fixed
F
SW
= 2.2 MHz (FPWM)
Figure 1.
Efficiency 3.3-V Output, FPWM
V
OUT
= 5 V Fixed
F
SW-NOM
= 2.2 MHz (Auto)
Figure 3.
Efficiency 5-V Output, Auto Mode
I
Load
= 300 mA
V
OUT
= 5 V Fixed
F
SW-NOM
= 2.2 MHz (Auto)
Figure 5.
Dropout at Power-Up and Power-Down
V
OUT
= 5 V Fixed
F
SW
= 2.2 MHz (FPWM)
Figure 2.
Efficiency 5-V Output, FPWM
Figure 4.
Typical Input Supply Current at
No Load for Fixed 3.3-V and 5-V Output
Figure 6.
Typical Start-up and Shutdown at
V
OUT
= 5 V