Offline 140W PD3.1 Adapter

PFC + Flyback with the MPX2002


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1. Overview

1.1 Description

The EVX2002-44018A-00B is a 140W, USB Type-C power delivery (PD) 3.1 reference design board. It features a very small form factor with a high power density. Its electrical specifications are well-suited for cellphone and computer power adapters. The reference design board provides very low no-load power consumption, and its high overall efficiency meets DOE Level VI and CoC Tier 2.

The MP44018A is a critical conduction mode (CrM) / discontinuous conduction mode (DCM), multi-mode power factor correction (PFC) controller that provides simple and high-performance active PFC using minimal external components. The switching frequency (fSW) is reduced by dead time (DT) extension technology under light-load conditions, which improves light-load efficiency. The MP44018A also achieves reduced total harmonic distortion (THD) due to variable on-time control in DCM when compared to conventional constant-on-time (COT) control.

The MPX2002 is an all-in-one flyback controller with an integrated primary driving circuit, secondary controller, synchronous rectification driver, and safety-compliant feedback. The device offers the benefits of both primary-side regulation (PSR) and secondary-side regulation (SSR).The MPX2002 adopts novel quasi-resonant (QR) mode switching when it runs in DCM. Due to this feature, the power supply has improved efficiency. Under very light loads, the controller enters burst mode to achieve very low standby power consumption. The MPX2002 offers frequency jittering to help dissipate the energy generated by conducted noise.

The EVX2002-44018A-00B is a reference design for a universal offline, isolated power supply with a 28V/5A, 20V/5A, 15V/3A, 12V/3A, 9V/3A, or 5V/3A output. This datasheet contains the complete specification of the power supply, a detailed circuit diagram, the entire bill of materials required to build the power supply, a drawing of the transformers, and performance testing.

1.2. Features

  • Wide Operating Input Voltage (VIN) Range (from 90V to 265V)
  • High Power Density
  • Low No-Load Consumption
  • Meets DOE VI/CoC Tier 2 Efficiency
  • Meets EN55022 Class B Emissions
  • Surge Endurance: 2kV
  • Short-Circuit Protection (SCP)
  • Over-Voltage Protection (OVP)
  • Under-Voltage Protection (UVP)
  • Over-Temperature Protection (OTP)

1.3. Applications

  • Laptop Charging
  • Mobile Phone Charging

Figure 1: Top View

2 Reference Design

2.1 Block Diagram

Figure 2 shows the reference design board’s system block.

Figure 2: Block Diagram

2.2 Related Solutions

This reference design is based on the following MPS solutions:

Table 1: System Integrated Circuits

MPS Integrated Circuit Description
MPX2002 All-in-one flyback controller
MP44018A CrM/DCM multi-mode PFC controller
HF81 X-capacitor bleeder
MPQ2013A Low quiescent current linear regulator

System Specifications

Table 2: System Specifications

MPS Integrated Circuit Description
Input voltage (VIN) range 90VAC to 265VAC
Output voltage (VOUT) 28/20/15/12/9/5V
Nominal load 28V/5A, 20V/5A, 15V/3A, 12V/3A, 9V/3A, 5V/3A
PF >0.93 at full load
Efficiency >92.3% at full load
No Load-Consumption <100mW
Output Voltage Ripple <200mV
Line Regulation <±3%
Load Regulation <±3%
Short-Circuit Protection Latch
Board form factor 62mmx59mmx23.5mm

3 Design

3.5 Schematics

Figure 3: PFC Stage

Figure 4: Flyback Stage

Figure 5: PD Output Stage

3.9 PCB Layout

Figure 12: Top Layer

Figure 13: Mid-Layer 1

Figure 14: Mid-Layer 2

Figure 15: Bottom Layer