MEZS7-PDPowerbank-MP2651 Reference Design

REFERENCE DESIGN

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Performance Summary ⁽¹⁾

Specifications are at T_A = 25°C, unless otherwise noted.

1) Refer to the MP2651 datasheet for more details.

2) These parameters can be configured by the MPF52002 via the I²C interface.

3) These parameters are configured automatically by the MPF52002, according to protocol.

Evaluation Board

LxWxH (6cmx5cmx2.1cm)

Table 1: Battery Cell Number Setting ⁽⁴⁾

4) Set PB2 and PB3 to configure the number of cells before charging a real battery.

Quick Start Guide

The MEZS7-PDPowerBank-MP2651 solution module is a reference design for USB PD applications, and includes a DRP USB Type-C port. The charge current is preset to 3A, and the charge-full voltage is preset to 8.4V for a 2-cell series Li-ion battery. In reverse source mode, the output is preset at 5V/3A or 27W PD.

The user can download their own charge parameter settings to the MPF52002’s volatile memory via the I²C after start-up. Data in the volatile memory resets when the part turns off. The user can also download these parameters to the MPF52002’s non-volatile memory (NVM). Data in the NVM does not reset even when the part turns off.

To prepare the battery connections for testing, follow the steps below:

1. Connect the series battery terminals to:
• Positive (+): VBATT
• Negative (-): GND


2. If a battery simulator is used:
1. Preset the battery voltage, then turn off the simulator.
2. Connect the battery simulator output terminals to:
• Positive (+): VBATT
• Negative (-): GND
3. Turn the battery simulator on.



Before plugging in the adapter, ensure that the settings for PB2 and PB3 are correct (see Figure 1). Otherwise, the system load and battery may be damaged.

Sink Mode

The MPF52002 automatically requests the maximum input power (P_IN) according to the adapter’s protocol. Connect the USB Type-C port to an adapter with either a USB Type-C to USB Type-C or a USB Type-A to USB Type-C cable. The MP2651’s input current (I_IN) limit and adapter’s output voltage (V_OUT) are set according to the protocol. After that, the device will start the charge operation. For 2-cell applications, the default battery full regulation voltage is 8.4V, and the charge current limit is set to 3A.

The default firmware of the MPF52002 on this evaluation board supports the following protocols in sink mode:

• PD3.1 V1.8
• For a non-PD adapter, the bus voltage (V_BUS) is 5V. The default input current (I_IN) limit is 900mA. If there is a R_P on source CC termination, the I_IN limit can rise to 1.5A or 3A, according to the R_P value.



The charge current may be limited by the input power (P_IN). If the maximum adapter output power is less than the MEZS7-PDPowerbank-MP2651’s output power (P_OUT), the I_IN limit loop adjusts the charge current to avoid overloading the source adapter.

Figure 1 shows the set-up for sink mode.



Figure 1: Sink Mode Set-Up

Source Mode

Connect the devices to a USB Type-C port using a USB Type-C to USB Type-C, USB Type-C to micro-B, or USB Type-C to lighting cable. Source mode can start automatically and provide proper voltage to the devices as requested.

The default firmware for the MPF52002 on this evaluation board supports the following protocols in source mode:



• PD3.1 V1.8
• DCP
• Apple mode




V_BUS starts up automatically at the voltage set by the PD protocol sniffer or mobile device. The PD protocol sniffer can select different PDO outputs. The default PD output power (P_OUT) is 27W. The battery discharge current limit is 6.4A.




Figure 2 shows the set-up for source mode.



Figure 2: Source Mode Set-Up

I²C Target Function Description

The MP2651 and the MPF52002 can be controlled or monitored via the I²C between the MPF52002 and the I²C initiator. The initiator should connect to the MPF52002 via PB6 and PB7 instead of the MP2651 (see Figure 3). The MPF52002 periodically reads the charge parameters, alerts the status of the MP2651, and updates the information to the I²C target registers. The initiator can also send some I²C commands to the MP2651 through the MPF52002.



Figure 3: MPF52002 I²C Target Diagram Block

I²C Connection Hardware Set-Up

In only battery mode, the MPF52002 can enter deep sleep to save power, and the I²C target registers are disabled. There are two methods to turn the I²C target function back on:



1. Short the INT pin in CN3 (PB1) to GND.
2. Connect a USB Type-C device or adapter to the USB Type-C port.



Next, connect the PC and the MEZS7-PDPowerbank-MP2651 with the EVKT-USBI2C-02 communication interface ⁽⁵⁾ (see Figure 4). The I²C SCL line should be connected via PB6, which has the SWDIO silkscreen print, and the I²C SDA line should be connected on PB7, which has the SWCLK silkscreen print.



Figure 4: Hardware Connected for the I²C Communication




5) Contact an MPS FAE or request through the MPS website to obtain the EVKT-USBI2C-02 communication interface.




Time Requirements for the I²C Initiator

• The initiator SCL clock frequency is 400kHz (fast mode), compliant with the 100kHz to 400kHz clock.
• Read or write 1 byte in every command. The MPF52002 does not support read/write multiple bytes.
• It is recommended to have a 10ms or longer delay between I²C commands.




Evaluation Board Schematic ^{(6) (7)}



Figure 5: Evaluation Board Schematic




6) A 0.1μF capacitor (Cx) can be paralleled on R9 to avoid inrush current when ACGATE turns on the MOSFET Q1.

7) PB6/7 can be used as the SWD interface. Before downloading any new firmware with the SWD interface, pull PA3 (boot 0) down to restart the MPF52002. When the firmware update is finished, disconnect PB6/7 from the SWD interface and release PA3, then turn the device on to load the new firmware




MEZS7-PDPowerbank-MP2651 Bill Of Materials

Qty	Ref	Value	Description	Package	Manufacturer	Manufacturer PN
2	C1, C2	4.7μF	Ceramic capacitor, 16V, X7R	0805	Murata	GCM21BR71C475KA73L
5	C3, C20, C27, C34, C35	NS
2	C4, C5	1μF	Ceramic capacitor, 25V, X7R	0603	Wurth	885012207078
13	C6, C7, C8, C12, C13, C14, C17, C23, C24, C29, C36, C37, C38	100nF	Ceramic capacitor, 25V, X7R	0603	Wurth	885012206071
2	C9, C19	100nF	Ceramic capacitor, 25V, X7R	0402	Murata	GRM155R71E104KE14D
4	C10, C11, C25, C26	22μF	Ceramic capacitor, 25V, X5R	0805	Murata	GRM21BR61E226ME44L
4	C15, C16, C21, C22	10μF	Ceramic capacitor, 25V, X7S	0805	Murata	GRM21BC7E106KE11L
1	C18	4.7μF	Ceramic capacitor, 25V, X5R	0603	Murata	GRM188R61E475KE11D
1	C28	10nF	Ceramic capacitor, 25V, X7R	0603	TDK	C1608X7R1E103K
2	C30, C31	4.7μF	Ceramic capacitor, 16V, X5R	0603	Murata	GRM188R61C475KE11D
2	C32, C33	1nF	Ceramic capacitor, 25V, C0G	0603	Murata	GRM1885C1E102JA01D
1	C39	100μF	Hybrid, 25V, 20mΩ	SMD	Nippon Chemi-Con	HHXC250ARA101MF80G
1	R1	2.7MΩ	Film resistor, 1%	0603	Yageo	RC0603FR-132M7L
5	R2, R3, R17, R23, R29	0Ω	Film resistor, 5%	0603	Yageo	RC0603JR-070RL
1	R4	1.1MΩ	Film resistor, 1%	0603	Yageo	RC0603FR-071M1L
4	R5, R6, R7, R10	5.1Ω	Film resistor, 1%	0603	Yageo	RC0603FR-075R1L
2	R8, R12	10mΩ	Current-sensing resistor, 1%, long side, 1W	L1508	Film Tech	RL3720WT-R010-F
1	R9	5.1MΩ	Film resistor, 5%	0603	Yageo	RC0603FR-075M1L
5	R11, R15, R30, R32, RB	NS
1	R13	200kΩ	Film resistor, 1%	0603	Yageo	RC0603FR-07200KL
3	R14, R34, R35	10Ω	Film resistor, 1%	0603	Yageo	RC0603FR-0710RL
1	R16	13kΩ	Film resistor, 1%	0603	Yageo	RC0603FR-0713KL
3	R18, R25, R31	100kΩ	Film resistor, 1%	0603	Yageo	RC0603FR-07100KL
3	R19, R27, R28	2.2kΩ	Film resistor, 5%	0603	Liz	CR0603JA0222G
1	R20	15kΩ	Film resistor, 1%	0603	Yageo	RC0603FR-0715KL
4	R21, R22, R36, R37	2.2Ω	Film resistor, 1%	0603	Yageo	RC0603FR-072R2L
2	R24, R26	5.1kΩ	Film resistor, 1%	0603	Yageo	RC0603FR-075K1L
1	R33	3.6kΩ	Film resistor, 5%	0603	Liz	CR0603JA0362G
1	R38	0Ω	Film resistor, 5%	0805	Yageo	RC0805FR-070RL
1	RNTC1	10kΩ	Film resistor, 1%	0603	Yageo	RC0603FR-0710KL
7	JP1, CN2, CN3, CN4, CN5, CN6, CN7	2.54mm	3-pin, 1-row	DIP	Wurth	61300311121
1	CN1	2.54mm	5-pin, 2-row	DIP	Wurth	61301021121
1	TYPE_C1	USB	USB Type-C receptacle, 16-pin	SMD	Yuehu Electronics	PC-071603863-R
4	VBUS, GND, VBAT	Φ2.0	Copper pin	DIP
1	CFLR	NS
1	LED1	Red	LED	0805	Wurth	150080RS75000
2	D1, D2	IR = 20µA	Schottky diode, 0.5A	SOD123	AUK	SDB0540
1	D3	5V	ESD diode	SOT-363	onsemi	ESD1L001
2	D4, D5	VF = 0.4V when IF = 1mA	60V, 15mA	SOD-323	Diodes, Inc.	SD101AWS
1	Q1	8.5mΩ	MOSFET	PowerPAK1212-8 (3.3mmx3.3mm)	Vishay	SISA14DN-T1-GE3
1	Q2	NS	MOSFET
1	L1	1.5μH	Inductor, 9.7mΩ, 9A	SMD	MPS	MPL-AL5030-1R5
1	U1	MP2013A	Low-power linear regulator	QFN-8 (3mmx3mm)	MPS	MP2013AGQ-5
1	U2	MP2651	Buck-boost charger for battery packs with 1 to 4 cells in series	TQFN-30 (4mmx5mm)	MPS	MP2651GVT-000A
1	U3	MPF52002	Highly integrated USB PD controller with a 32-bit ARM Cortex-M0 microcontroller	QFN-24 (4mmx4mm)	MPS	MPF52002-0001




EVB Test Results

Performance curves and waveforms are tested on the evaluation board. The input power source is a USB PD adapter, V_IN = 20V, V_BATT = 8V, T_A = 25°C, default register data, unless otherwise noted.




PCB Layout



Figure 6: Top Layer



Figure 7: Mid-Layer 1



Figure 8: Mid-Layer 2



Figure 9: Bottom Layer