User Guide🔗

Introduction🔗

The PAN9028 M.2 device (ENWF9408AMEF) is an evaluation device (EVD) ideally suited for use of the module in conjunction with host processor evaluation kits that have a M.2 Key E socket.

It features a PAN9028 with an integrated Power Management IC (ENWF9408A1EF).

Features🔗

M.2 Key E form factor
External antenna U.FL connector
Coexistence interface
Wi-Fi and Bluetooth status indicator LEDs
PCM interface

Block Diagram🔗

Board Overview🔗

1 The module

2 Mounting screw indentation
You can use the mounting screw indentation to secure the board in a M.2 Key E socket. Also see Mounting the Device

3 External antenna U.FL connector - ANT1
You can use the U.FL connector to connect an external antenna. Also see Antenna Configuration

4 Wi-Fi status indicator LED
The Wi-Fi status indicator LED for indicating the Wi-Fi status is currently non-operational.

5 Bluetooth status indicator LED
The Bluetooth status indicator LED for indicating the Bluetooth status is currently non-operational.

6 M.2 Key E connector
You can insert the PAN9028 M.2 device into a M.2 Key E socket to connect the modules interfaces to a host processor. Also see M.2 Connector Pin Map

7 Power LED
You can observe the power LED to verify that the board is correctly powered.

Device Dimensions🔗

Initial Preparations🔗

Mounting the Device🔗

To mount the PAN9028 M.2 device in a M.2 Key E socket on a host board execute the following instructions.

Line up the notch on the M.2 Key E connector 6 with the key of the M.2 Key E socket of the host board.
Insert the PAN9028 M.2 device into the socket slightly angled.
Apply some light downward pressure until the PAN9028 M.2 device is parallel to the host board and makes contact to the threaded insert.
Insert a M2.5 x 4 machine screw into the mounting screw indentation 2 and the threaded insert.

The PAN9028 M.2 device is secured in place.

M.2 Connector Pin Map🔗

Description	M.2 Key E Pin	Function	Module Footprint	Module Pin
SDIO Interface	9	SDIO CLK	G5	SD_CLK
	11	SDIO CMD	G6	SD_CMD
	13	SDIO DATA0	G7	SD_DAT0
	15	SDIO DATA1	G8	SD_DAT1
	17	SDIO DATA2	G9	SD_DAT2
	19	SDIO DATA3	G10	SD_DAT3
UART Interface	22	UART RXD / GPIO8	B8	UART_SOUT / IO8
	32	UART TXD / GPIO9	A8	UART_SIN / IO9
	34	UART RTS / GPIO11	A7	UART_RTS / IO11
	36	UART CTS / GPIO10	B8	UART_CTS / IO10
Status LEDs	6	Wi-Fi LED / GPIO2	F8	LED_WLAN / IO2
Status LEDs	16	Bluetooth LED / GPIO3	F9	LED_BT / IO3
PCM Interface	8	I2S SCK / GPIO6	E1	PCM_CLK / IO6
	10	I2S WS / GPIO7	F6	PCM_SYNC / IO7
	12	I2S SD IN / GPIO5	F7	PCM_DOUT / IO5
	14	I2S SD OUT / GPIO4	F10	PCM_DIN / IO4
Coexistence Interface	46	Coexistence RXD / GPIO17	B10	COEX_OUT / IO17
Coexistence Interface	48	Coexistence TXD / GPIO16	F5	COEX_SIN / IO16
Clock	50	32 KHz Oscillator	E6	32KHZ_IN
Power	2, 4, 72, 74	3.3 V	F2, F3	VDD3V3
	56	PMIC Enable	A2	PMIC_EN
	1, 7, 18, 33, 39, 45, 57, 63, 69, 75	GND	A1, A12, B12, C11, C12, D11, D12, E11, E12, F1, F11, F12, G11, EP1, EP2, EP3, EP4	GND, EPAD1, EPAD2, EPAD3, EPAD4
not connected	3, 5, 7, 20, 21, 23, 35, 37, 38, 40, 41, 42, 43, 44, 47, 49, 52, 53, 54, 55, 58, 59, 60, 61, 62, 64, 65, 66, 67, 68, 70, 71, 73	not connected	N/A	N/A

Clock Configuration Pin

The UART_SOUT (M.2 Key E pin 22) doubles as a configuration pin for the clock frequency used by the PAN9028.

Only the 26 MHz configuration is valid since the PAN9028 includes a crystal with this frequency.

Keep this pin floating or on logical high level during firmware initialization. A low level during firmware initialization prevents the firmware from starting up.

Hardware Modifications🔗

You can modify the PAN9028 M.2 device to suit your application and your specific host processor by making some hardware modifications.

The following sections describe how you can reconfigure the reference voltages and how you activate the external antenna U.FL connector ANT1 3.

SDIO Reference Voltage🔗

In case your host processor board only supports a SDIO signal voltage of 3.3 V you can reconfigure the PAN9028 M.2 device to use the 3.3 V generated by the PMIC as V_IOSD.

The PAN9028 supports 1-bit or 4-bit SDIO transfer modes with full clock range up to 208 MHz. The SDIO Interface pins are powered from the V_IOSD voltage supply with either 1.8 V or 3.3 V.

On the PAN9028 M.2 device by default V_IOSD is connected to the V_OUT1V8 of the PMIC, hence it is set to 1.8 V.

IO Reference Voltage

Setting V_IOSD to 3.3 V also configures the IO reference voltage to be 3.3 V as well.

To set V_IOSD to 3.3 V execute the following instructions.

Unsolder the resistors R8 and R9.
Place a 0 Ohm resistor (0402) for R13 and or bridge it with a solder blob.
Place a 0 Ohm resistor (0402) for R10 and or bridge it with a solder blob.

This connects V_IOSD to 3.3 V.

Note

SDIO clock speeds higher than 50 MHz can only be achieved with a SDIO signal voltage level (V_IOSD) of 1.8 V and a host processor that supports the SDIO 3.0 Standard.

The maximum achievable data rate is limited by the used SDIO clock speed.

For further information please refer to the module product specification at

IO Reference Voltage🔗

In case your host processor board supports only IO voltage levels of 3.3 V you can reconfigure the PAN9028 M.2 device to use 3.3 V as voltage level for its UART and IOs.

The voltage used by the IOs and the UART interface is determined by the voltage applied to V_IO. You can configure it to either 1.8 V or 3.3 V.

On the PAN9028 M.2 device by default V_IO is connected to V_OUT1V8 of the PMIC, hence it is set to 1.8 V.

Warning

In case you have set V_IOSD to 3.3 V as described in SDIO Reference Voltage the IO reference voltage is also configured to be 3.3 V.

Please note, if V_IOSD is set to 3.3 V it is not possible to set the IO reference voltage to 1.8 V since this would create a short between 3.3 V and 1.8 V.

To set V_IO to 3.3 V execute the following instructions.

Unsolder R8.
Place a 0 Ohm resistor (0402) for R13 or bridge it with a solder blob.

This connects V_IO to 3.3 V.

Antenna Configuration🔗

You can evaluate PAN9028 M.2 device in conjunction with an external antenna by activating the external antenna U.FL connector ANT1 3 with some hardware modifications. By default the chip antenna is active.

External Antenna

To activate the external antenna U.FL connector ANT1 3 execute the following instructions.

Unsolder R3.
Place a 0 Ohm resistor (0402) for R4 or bridge it with a solder blob.

Chip Antenna

In case you modified the PAN9028 M.2 device to use the external antenna U.FL connector ANT1 3 execute the following instructions to switch back to the chip antenna.

Unsolder R4.
Place a 0 Ohm resistor (0402) for R3 or bridge it with a solder blob.