Fully integrated automotive USB Type-A and USB Type-C charger controller IC

Introduction

The central control system of a car usually provides a USB charging port, which needs to charge mobile devices while transmitting data. For these systems, it is very important to choose an automotive-grade IC with a USB current-limiting switch. This article will introduce MPS's USB charging port buck converter MPQ4228-C-AEC1 and how to apply its high efficiency advantages to USB hubs and other USB Type-C and USB Type-A applications.

MPQ4228-C-AEC1

The MPQ4228-C-AEC1 provides a USB charging solution with an integrated step-down switch-mode converter and a USB current-limiting switch (see Figure 1). It supports BC1.2 CDP mode and USB Type-C 5V @ 3A DFP mode and is available in a small QFN-22 (4mmx4mm) package. The device integrates a synchronous DC/DC step-down converter and a charger port controller supporting CDP mode, which reduces component count, thereby improving EMI performance and reducing PCB size.

Figure 1: MPQ4228-C-AEC1 typical application circuit

The MPQ4228-C-AEC1 provides a variety of powerful protection functions, including hiccup mode current limiting protection (supporting MFI OCP), output overvoltage protection (OVP), USB_OUT/DP/DM/CC1/CC2 to battery short circuit protection, and over temperature protection (OTP).

The MPQ4228-C-AEC1 can also be used in USB Type-A and USB Type-C applications. Its CC2 pin detects connection to configure the interface between the USB Type-C cable and connector. When the CC1 pin is grounded, the MPQ4228-C-AEC1 operates in USB Type-A mode with current limits that comply with the USB Type-A specification.

efficiency

The MPQ4428-C-AEC1 uses a high-efficiency DC/DC converter with a peak efficiency of up to 94.4% and a total load temperature rise of only 31°C. Due to the device's high efficiency, it generates very little heat, which not only reduces the need for heat dissipation, but also reduces the overall solution size. Its efficiency curve is shown in Figure 2.

Figure 2: Efficiency vs. load current

Case temperature test

Figure 3 shows the case temperature test results of MPQ4228-C-AEC1. The test conditions are: input voltage (VIN) = 12V, USB = 5V, output current (IOUT) = 3A. The measurement is performed on a 4-layer PCB (57.4mmx57.4mm); the top and bottom layers are 2oz, and the middle layer 1 and middle layer 2 are 1oz. The ambient temperature (TA) is 25°C.

Figure 3: Case temperature test

Data Transfer

Data transmission requires excellent signal integrity, and the integrity of USB 2.0 signals can be evaluated through eye diagram testing. As shown in Figure 4, 150cm cable has excellent eye diagram performance when host data passes through the internal DP/DM data switch of MPQ4228-C-AEC1. In this test, VIN = 12V, switching frequency (fSW) = 420kHz.

Figure 4: Eye diagram

Electromagnetic Interference (EMI)

With the continuous development of automotive electronic products, the requirements for the electromagnetic compatibility (EMC) performance of the whole vehicle are becoming more and more stringent. Electromagnetic interference (EMI) can degrade device performance; in some applications, it may have a more obvious impact, such as noise generated by the radio.

MPQ4228-C-AEC1 has a spectrum spreading function and can pass CISPR25 Class 5 standard without shielding and common mode inductor. Figure 5 shows its conducted EMI test results. The test conditions are: VIN = 12V, bus voltage (VBUS) = 5V, IOUT = 3A, inductor (L) = 4.7µH, fSW = 420kHz, FREQ pin connected to GND, and the operation mode is forced pulse width modulation (PWM) mode.

Figure 5: Conducted EMI test results

The radiated EMI test results are shown in Figure 6. The test conditions are the same as those for conducted EMI.

Figure 6: Radiated EMI test results

Line voltage drop compensation

There is a certain distance between the vehicle and the USB port, and the line voltage drop during this distance will affect the charging voltage and charging speed of the terminal. Moreover, this distance varies in different models. MPQ4228-C-AEC1 defines a flexibly configurable line loss compensation for this problem.

Figure 7: Line voltage drop compensation vs. load current

The MPQ4228-C-AEC1 is a member of the MPQ4228 series. The series also includes the following devices:

MPQ4228-AEC1 supports Apple 3A Divider mode as well as BC1.2 and 1.2V/1.2V mode DCP solutions.

MPQ4228-Q-AEC1 supports fast charging (QC3.0) mode and is backward compatible with BC1.2, Apple 3A Divider mode and 1.2V/1.2V mode DCP solutions.

The MPQ4228 series provides short-to-battery protection through the VBUS/DM/DP/CC pins and can pass the ±8kV IEC 61000-4-2 contact discharge test and the ±15kV IEC 61000-4-2 air discharge test.

Conclusion

This article introduces the advantages of MPQ4228-C-AEC1, such as high efficiency, excellent EMI performance and optimized thermal performance. In addition, you can also refer to this video to learn about another product in the MPQ4228 series, MPQ4228-AEC1. MPS offers a range of powerful and AECQ-100 certified USB charging ports to meet any design needs.