ANALOG DEVICES ADPL54203-AZ Micropower No Opto Isolated Flyback Converter User Guide

ANALOG DEVICES ADPL54203-AZ Micropower No Opto Isolated Flyback Converter

General Description

The evaluation circuit EVAL-ADPL54203-AZ is a micropower no-opto isolated flyback converter featuring the ADPL54203. This demo circuit outputs 5V and maintains tight regulation with a load current from 10mA to 2.2A over an input voltage from 10V to 28V. The output current capability increases with the input voltage. The ADPL54203 typically needs less than 0.5% of its full output power as a minimum load to maintain good output voltage regulation. On the EVAL ADPL54203-AZ, to avoid preloading, a 5.6V Zener diode is placed between its VOUT+ and VOUT– to serve as a minimum load.

Transformer leakage inductance causes a voltage spike on the primary side after the power switch turns off. To limit this leakage inductance spike within the MOSFET voltage rating of 60V, an RC snubber and a TVS clamp are installed to dampen the ringing and clamp the MOSFET drain voltage to a safe level.

The Performance Summary table summarizes the performance of the demo board at room temperature. The demo circuit can be easily modified for different \applications with some predesigned transformers. The ADPL54203 is a simple- to-use monolithic micropower isolated flyback converter. By sampling the isolated output voltage directly from the primary-side flyback waveform, the part requires no third winding or optoisolator for \regulation. The output voltage is programmed with two external resistors and a third optional temperature compensation resistor. By integrating the loop compensation and soft-start inside, the part reduces the number of external components. Boundary mode operation provides a small magnetic solution with excellent load regulation.

Low ripple Burst Mode® operation maintains high efficiency at light load while minimizing the output voltage ripple. A 3.4A, 60V DMOS power switch is integrated along with all the high-voltage circuitry and control logic into a thermally enhanced 8-lead SO package. The ADPL54203 data sheet gives a complete description of the part, operation and application information and must be consulted with this quick start guide for evaluation circuit EVAL- ADPL54203-AZ. Design files for this circuit board are available at Product

Performance Summary (TA = 25C)

Quick Start Procedure

The evaluation circuit EVAL-ADPL54203-AZ is easy to set up to evaluate the performance of the ADPL54203. For proper measurement equipment setup, see Figure 1 and do the following procedures

1. With power off, connect the input power supply to the board through VIN (TP1) and GND (TP2) terminals. Connect the load to the terminals VOUT+ (TP3) and VOUT– (TP4) on the board.

2. Turn on the power at the input. Increase VIN slowly to 10V.
   NOTE: Make sure that the input voltage is always within spec. To operate the board with higher input/output voltage, input/output capacitor, and output diode with higher voltage ratings are needed.

3. Check for the proper output voltages. The output should be regulated at 5.0V (±5%).
   NOTE: The EVAL-ADPL54203-AZ requires a very small minimum load to maintain good output voltage regulation. A Zener diode is placed on the output to clamp the voltage to 5.6V. This Zener diode can be replaced with a560Ω resistor at the trade-off of lower efficiency.

4. Once the proper output voltage is established, adjust the input voltage and load current within the operating range and observe the output voltage regulation, ripple voltage, efficiency, and other parameters.
   NOTE: When measuring the input or output voltage ripple, care must be taken to avoid a long ground lead on the oscilloscope probe. Measure the input or output voltage ripple by touching the probe tip directly across the
   VIN (TP1) and GND (TP2), or VOUT+ (TP3) and VOUT– (TP4) terminals.

Performance
(TA = +25C unless otherwise noted.)

Bill of Materials

ITEM| QTY| DESIGNATOR| DESCRIPTION| MANUFACTURER, PART NUMBER
---|---|---|---|---
REQUIRED CIRCUIT COMPONENTS
1| 1| C1| Aluminum Electrolytic Capacitor, 22µF, 50V, 20%, 6.3mm × 5.8mm, 0.165A, 2000h, AEC-Q200| Panasonic, EEEFK1H220P
2| 1| C2| Ceramic Capacitor, 10µF, 50V, 10%, X7R, 1210| Murata, GRM32ER71H106KA12L
3| 1| C3| Ceramic Capacitor, 1µF, 25V, 10%, X5R, 0603| AVX Corporation, 06033D105KAT2A
4| 1| C4| Ceramic Capacitor, 220pF, 50V, 5%, C0G, 0805| Yageo, CC0805JRNPO9BN221
5| 3| C5, C6, C7| Ceramic Capacitors, 100µF, 10V, 20%, X5R, 1210| Samsung, CL32A107MPVNNNE
6| 1| C8| Ceramic Capacitor, 4700pF, 250V, 10%, X7R, 1812| Murata, GA343DR7GD472KW01L
7| 1| D1| Diode, Low Forward Voltage (VF), Schottky Barrier

Rectifier

| Diodes Incorporated, PDS1040L
8| 1| D2| Silicon Zener Diode| Central Semiconductor, CMHZ5232B TR
9| 1| D3| Voltage Suppressor Diode| Diodes Incorporated, SMAJ18A-13-F
10| 1| D4| Schottky Rectifier Diode, 1A| Central Semiconductor, CMMSH1-100G TR
11| 1| R1| Resistor, SMD, 1MΩ, 1%, 1/10W, 0603, AEC-Q200| Panasonic, ERJ- 3EKF1004V
12| 1| R2| Resistor, SMD, 200kΩ, 1%, 1/10W, 0603, AEC-Q200| Panasonic, ERJ- 3EKF2003V
13| 1| R3| Resistor, SMD, 100Ω, 1%, 1/4W, 1206| Yageo, RC1206FR-07100RL
14| 1| R4| Resistor, SMD 150kΩ, 1%, 1/10W, 0603, AEC-Q200| Panasonic, ERJ- 3EKF1503V
15| 1| R5| Resistor, SMD, 113kΩ, 1%, 1/10W, 0603, AEC-Q200| Panasonic, ERJ- 3EKF1133V
16| 1| R6| Resistor, SMD, 10kΩ, 1%, 1/10W, 0603, AEC-Q200| Panasonic, ERJ- 3EKF1002V
17| 1| T1| Switching Flyback Transformer| Wurth Elektronik, 750311564
18| 1| U1| IC-ADI Micropower No-Opto Isolated Flyback

Converter

| Analog Devices Inc.,

ADPL54203ES8E#PBF

HARDWARE – FOR DEMO BOARD ONLY

1

| ****

4

| TP1, TP2, TP3, TP4| PCB-Connectors, Solder Terminal Test Point Turret, Mounting Hole Diameter 0.094″, PCB Thickness

0.062″

| ****

Mill-Max, 2501-2-00-80-00-00-07-0

Evaluation Board Schematic

Revision History

ASSUMED BY ANALOG DEVICES FOR ITS USE, NOR FOR ANY INFRINGEMENTS OF PATENTS OR OTHER RIGHTS OF THIRD PARTIES THAT MAY RESULT FROM ITS USE. SPECIFICATIONS ARE SUBJECT TO CHANGE WITHOUT NOTICE. NO LICENCE, EITHER EXPRESSED OR IMPLIED, IS GRANTED UNDER ANY ADI PATENT RIGHT, COPYRIGHT, MASK WORK RIGHT, OR ANY OTHER ADI INTELLECTUAL PROPERTY RIGHT RELATING TO ANY COMBINATION, MACHINE, OR PROCESS WHICH ADI PRODUCTS ALL INFORMATION CONTAINED HEREIN IS PROVIDED “AS IS” WITHOUT REPRESENTATION OR WARRANTY. NO RESPONSIBILITY IS OR SERVICES ARE USED. TRADEMARKS AND REGISTERED TRADEMARKS ARE THE PROPERTY OF THEIR RESPECTIVE OWNERS. analog.com

References

• Mixed-signal and digital signal processing ICs | Analog Devices
• Document Feedback Form | Analog Devices
• ADPL54203 Datasheet and Product Info | Analog Devices
• Product Evaluation Boards and Kits | Analog Devices
• Mixed-signal and digital signal processing ICs | Analog Devices

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