DPA426SN Power Integrations, DPA426SN Datasheet

IC CONV DC-DC DPA SWITCH SPAK

DPA426SN

Manufacturer Part Number
DPA426SN
Description
IC CONV DC-DC DPA SWITCH SPAK
Manufacturer
Power Integrations
Series
DPA-Switch®r
Datasheets

Specifications of DPA426SN

Applications
Converter, Power Over Ethernet and Telecom Applications
Voltage - Input
16 ~ 75 V
Number Of Outputs
1
Voltage - Output
220V
Operating Temperature
-40°C ~ 125°C
Mounting Type
Surface Mount
Package / Case
SPak (5 leads + Tab)
Mounting Style
SMD/SMT
Lead Free Status / RoHS Status
Lead free / RoHS Compliant

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
DPA426SN
Manufacturer:
POWER
Quantity:
15 000
DPA-Switch
Converter Design Guide
Application Note AN-31
Introduction
The single-ended forward converter topology is usually the
best solution for DC-DC applications in industrial controls,
Telecom central office equipment, digital feature phones, and
systems that use distributed power architectures.
The feature set of DPA-Switch offers the following advantages
in DC-DC single-ended forward converter designs:
• Low component count
• High efficiency (typically >91% with synchronous
• Built in soft-start to minimize stress and overshoot
• Built in accurate line under-voltage detection
• Built-in accurate line overvoltage shutdown protection
• Built in adjustable current limit
• Built-in overload and open loop fault protection
• Built-in thermal shutdown
• Programmable duty cycle reduction to limit duty cycle
• Very good light-load efficiency
Figure 1. Typical Configuration of DPA-Swtich in a Single-Ended DC-DC Forward Converter with One Output.
excursion at high line and transient load conditions
rectification)
INPUT
DC
+
Clamp
Drain
D
S
CONTROL
CONTROL
L
R
F
UVLO
DPA-Switch
DC-DC Forward
C
C
CLAMP
U1
Transformer
C
Power
BYPASS
R
C
FC
FC
Snubber
• Selectable 300 kHz or 400 kHz operation
• Lossless integrated cycle-by-cycle current limit
The example circuits in this design guide illustrate the use of
these and other features of DPA-Switch.
Scope
This document gives guidance for the design of a single-
ended forward converter with DPA-Switch in applications
that require a single output voltage. It is intended for systems
engineers and circuit designers who wish to become familiar
with the capabilities and requirements of DPA-Switch in
DC-DC applications. This application note provides background
material that will assist users of the DPA-Switch DC-DC forward
converter design utility that is included in the software design
tool, PI Expert. Subsequent application notes will provide
comprehensive procedures for designs of greater complexity.
Designers are advised to check Power Integrationsʼ website at
www.powerint.com for the latest application information and
design tools.
Input
Return
FEEDBACK CIRCUIT
Inductor
Voltage
Output
+
Bias
TL431 with
Frequency
Compensation
Output
Capacitor
PI-2873-062204
V
July 2004
+
O

Related parts for DPA426SN

DPA426SN Summary of contents

Page 1

... DPA-Switch DC-DC forward converter design utility that is included in the software design tool, PI Expert. Subsequent application notes will provide comprehensive procedures for designs of greater complexity. Designers are advised to check Power Integrationsʼ website at www.powerint.com for the latest application information and design tools. Snubber ...

Page 2

AN-31 Description Input Input Voltage Input Voltage UV Turn ON Input Voltage UV Turn Off Input Voltage OV Turn On Input Voltage OV Turn Off Output Output Voltage Output Ripple and Noise Output Current Line Regulation Load Regulation Transient Response ...

Page 3

DPA-Switch D L CONTROL CONTROL Input Derived (a) + DPA-Switch D L CONTROL CONTROL Output Coupled Inductor Bias (c) Figure 2. Methods for Generation of Bias Voltage. Output Rectifiers Output ...

Page 4

AN-31 Efficiency Designing a DC-DC converter with DPA-Switch involves several engineering tradeoffs that weigh efficiency against cost and complexity. The circuit configuration in Figure 1 achieves efficiencies greater than 85% over the range of input voltage at medium loads. In ...

Page 5

Input Voltage Bias Type Range (V) DC Input Derived Bias Transfer Bias (unregulated) Output Coupled Inductor Bias Transformer Bias (regulated) Table 2. Bias Voltage Solution Comparison. of input ...

Page 6

AN-31 90% 88% 86% 84% 82% 80 Input Voltage Figure 3. Efficiency of the Low Cost EP-21 Prototype with Different Devices in the DPA-Switch Family (Synchronous Rectification Would Improve Efficiency). If the transformer ...

Page 7

If power dissipation is a problem with the smallest device, select the next larger device and program the current limit with the X pin to 10% above the peak primary current. This is done to limit overload power capability. Refer ...

Page 8

AN-31 C3, C4, C5 µF, IN 100 V (x4) 36-72 VDC L1 J1-1 1 µH 2 UF4003 C8 470 pF 200 µF 1 µF 100 V 100 V L2 100 µH ...

Page 9

T S 200 150 100 50 0 -50 -100 2.5 0 Time (µs) (a) 300 250 200 150 100 50 0 -50 -100 2.5 0 Time (µs) (b) 300 250 200 150 ...

Page 10

AN-31 the transformer increases in the positive direction during t and resets to zero during the interval the magnetizing inductance is removed during t the reset capacitor and the clamp capacitor to maximum voltage. The flux increases ...

Page 11

DPA-Switch U1 D CONTROL CONTROL Figure 9. Essential Components of the Feedback Circuit. The Schematic Does Not Show ESR of the Output Capacitors (Component Designators are the Same as in the EP-21 Prototype). The phase margin is ...

Page 12

AN-31 60 1-Gain 56 dB Loop Gain Degrees Phase 30 180 Degrees Phase Margin 1-Phase -10 -20 -30 -40 P1 -50 -60 0.1 1 Figure 10. Gain and Phase of a Typical Feedback Loop ...

Page 13

The zero introduced by R4 and the ESR of C6 should be at approximately 25% of the output filter resonant frequency. This ...

Page 14

AN- µH IN 2.5 A 36-75 VDC R1 619 kΩ 1% C1, C2 & µF 100 V D CONTROL CONTROL S X VR1 SMBJ 150 V IN Figure 11. Example of DPA-Switch in a ...

Page 15

R15 Q1 Q2 (a) C17 R15 R16 (b) Figure 12. Synchronous Rectification (a) Winding Driven DC Coupled. (b) Winding Driven AC Coupled. output. For output, an efficiency of 85% with Schottky rectifiers would typically ...

Page 16

AN-31 Synchronous Rectifier Type Winding Driven DC Coupled Winding Driven AC Coupled Active Drive Table 4. Comparison of Synchronous Rectification Techniques. winding. Capacitor C17 should be chosen to capacitively divide the winding voltage between C17 and the C Q2, to ...

Page 17

Solder Side Component Side TOP VIEW V + DPA-Switch - Maximize hatched copper area for optimum heat sinking Via between board layers V Figure 13. Layout Considerations for DPA-Switch Using R Package. board material is used (such as FR4), providing ...

Page 18

AN-31 4. Thermal check – At maximum output power, minimum input voltage and maximum ambient temperature, verify that temperature specifications are not exceeded for the transformer, output diodes, output inductors and output capacitors. The DPA-Switch is fully protected against overtemperature ...

Page 19

AN- 7/04 ...

Page 20

... For the latest updates, visit our Web site: www.powerint.com Power Integrations may make changes to its products at any time. Power Integrations has no liability arising from your use of any information, device or circuit described herein nor does it convey any license under its patent rights or the rights of others. POWER INTEGRATIONS MAKES NO WARRANTIES HEREIN AND SPECIFICALLY DISCLAIMS ALL WARRANTIES INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT OF THIRD PARTY RIGHTS ...

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