SNAS714C
November 2016 – August 2021
LMS3635-Q1
,
LMS3655-Q1
PRODUCTION DATA
1
Features
2
Applications
3
Description
4
Revision History
5
Device Comparison Tables
6
Pin Configuration and Functions
7
Specifications
7.1
Absolute Maximum Ratings
7.2
ESD Ratings
7.3
Recommended Operating Conditions
7.4
Thermal Information
7.5
Thermal Information (for Device Mounted on PCB)
7.6
Electrical Characteristics
7.7
System Characteristics
7.8
Timing Requirements
7.9
Typical Characteristics
8
Detailed Description
8.1
Overview
8.2
Functional Block Diagram
8.2.1
Control Scheme
8.3
Feature Description
8.3.1
RESET Flag Output
8.3.2
Enable and Start-Up
8.3.3
Soft-Start Function
8.3.4
Current Limit
8.3.5
Hiccup Mode
8.3.6
Synchronizing Input
8.3.7
Undervoltage Lockout (UVLO) and Thermal Shutdown (TSD)
8.3.8
Input Supply Current
8.4
Device Functional Modes
8.4.1
AUTO Mode
8.4.2
FPWM Mode
8.4.3
Dropout
8.4.4
Spread-Spectrum Operation
9
Application and Implementation
9.1
Application Information
9.2
Typical Applications
9.2.1
General Application
9.2.1.1
Design Requirements
9.2.1.2
Detailed Design Procedure
9.2.1.2.1
Custom Design With WEBENCH® Tools
9.2.1.2.2
External Components Selection
9.2.1.2.2.1
Input Capacitors
9.2.1.2.2.2
Output Inductors and Capacitors
9.2.1.2.2.2.1
Inductor Selection
9.2.1.2.2.2.2
Output Capacitor Selection
9.2.1.2.3
Setting the Output Voltage
9.2.1.2.4
FB for Adjustable Output
9.2.1.2.5
VCC
9.2.1.2.6
BIAS
9.2.1.2.7
CBOOT
9.2.1.2.8
Maximum Ambient Temperature
9.2.1.3
Application Curves
9.2.2
Fixed 5-V Output for USB-Type Applications
9.2.2.1
Design Requirements
9.2.2.2
Detailed Design Procedure
9.2.2.3
Application Curves
9.2.3
Fixed 3.3-V Output
9.2.3.1
Design Requirements
9.2.3.2
Detailed Design Procedure
9.2.3.3
Application Curves
9.2.4
6-V Adjustable Output
9.2.4.1
Design Requirements
9.2.4.2
Detailed Design Procedure
9.2.4.3
Application Curves
9.3
Do's and Don't's
10
Power Supply Recommendations
11
Layout
11.1
Layout Guidelines
11.2
Layout Example
12
Device and Documentation Support
12.1
Device Support
12.1.1
Third-Party Products Disclaimer
12.1.2
Development Support
12.1.2.1
Custom Design With WEBENCH® Tools
12.2
Documentation Support
12.2.1
Related Documentation
12.3
Receiving Notification of Documentation Updates
12.4
Support Resources
12.5
Trademarks
12.6
Electrostatic Discharge Caution
12.7
Glossary
13
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
RNL|22
MPQF443E
Thermal pad, mechanical data (Package|Pins)
RNL|22
QFND674
Orderable Information
snas714c_oa
snas714c_pm
1
Features
AEC-Q100-qualified for automotive applications
Device temperature grade 1: –40°C to +125°C ambient operating temperature
Device HBM classification level 2
Device CDM classification level C6
96% Peak efficiency while converting 12 V to 5 V
Low EMI and minimized switch node ringing
400-kHz (±10%) fixed switching frequency
–40°C to +150°C junction temperature range
External frequency synchronization
RESET
output with internal filter and 3-ms release timer
Automatic light load mode for improved efficiency
Pin-selectable forced PWM mode
Built-In compensation, soft start, current limit, thermal shutdown, and UVLO
0.35-V dropout with 3.5-A Load at 25°C (Typical)
18-µA I
Q_VIN
: quiescent current at 3.3 V
OUT
and no load (typical)
Output voltage: 5 V, 3.3 V, and ADJ (1 V to 20 V)
±1.5% reference voltage tolerance
Create a custom design using the LMS3655-Q1 with the
WEBENCH®
Power Designer