SNVS120G
April 2000 – May 2019
LM2585
PRODUCTION DATA.
1
Features
2
Applications
3
Description
Device Images
12-V Flyback Regulator Design Example
4
Revision History
5
Pin Configurations
6
Specifications
6.1
Absolute Maximum Ratings
6.2
ESD Ratings
6.3
Recommended Operating Ratings
6.4
Thermal Information
6.5
Electrical Characteristics: 3.3 V
6.6
Electrical Characteristics: 5 V
6.7
Electrical Characteristics: 12-V
6.8
Electrical Characteristics: Adjustable
6.9
Electrical Characteristics: All Versions
6.10
Typical Characteristics
7
Detailed Description
7.1
Overview
7.2
Functional Block Diagram
7.3
Feature Description
7.3.1
Step-Up (Boost) Regulator Operation
8
Application and Implementation
8.1
Application Information
8.2
Typical Applications
8.2.1
Typical Boost Regulator Applications
8.2.2
Typical Flyback Regulator Applications
8.2.2.1
Transformer Selection (T)
8.2.2.2
Transformer Footprints
8.2.2.2.0.1
T6
8.2.2.2.0.2
T6
8.2.3
Design Requirements
8.2.4
Detailed Design Procedure
8.2.4.1
Custom Design With WEBENCH® Tools
8.2.4.2
Programming Output Voltage (Selecting R1 And R2)
8.2.4.3
Short Circuit Condition
8.2.4.4
Flyback Regulator Input Capacitors
8.2.4.5
Switch Voltage Limits
8.2.4.6
Output Voltage Limitations
8.2.4.7
Noisy Input Line Condition
8.2.4.8
Stability
8.2.5
Application Curve
8.3
Additional Application Examples
8.3.1
Test Circuits
9
Layout
9.1
Layout Guidelines
9.2
Heat Sink/Thermal Considerations
10
Device and Documentation Support
10.1
Device Support
10.1.1
Third-Party Products Disclaimer
10.1.2
Development Support
10.1.2.1
Custom Design With WEBENCH® Tools
10.2
Receiving Notification of Documentation Updates
10.3
Community Resources
10.4
Trademarks
10.5
Electrostatic Discharge Caution
10.6
Glossary
11
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
NDH|5
MMSF011
KTT|5
MPSF007E
Thermal pad, mechanical data (Package|Pins)
KTT|5
PPTD277
Orderable Information
snvs120g_oa
snvs120g_pm
8.3.1
Test Circuits
C
IN1
—100 μF, 25V Aluminum Electrolytic
C
IN2
—0.1 μF Ceramic
T—22 μH, 1:1 Schott #67141450
D—1N5820
C
OUT
—680 μF, 16V Aluminum Electrolytic
C
C
—0.47 μF Ceramic
R
C
—2k
Figure 47.
Lm2585-3.3 And Lm2585-5.0
C
IN1
—100 μF, 25V Aluminum Electrolytic
C
IN2
—0.1 μF Ceramic
L—15 μH, Renco #RL-5472-5
D—1N5820
C
OUT
—680 μF, 16V Aluminum Electrolytic
C
C
—0.47 μF Ceramic
R
C
—2k
For 12V Devices: R
1
= Short (0Ω) and R
2
= Open
For ADJ Devices: R
1
= 48.75k, ±0.1% and R2 = 5.62k, ±1%
Figure 48.
Lm2585-12 And Lm2585-Adj
Figure 49.
Flyback Regulator
Figure 50.
Boost Regulator