Product Info

LTE Standard Module Series
EC25 Series Hardware Design
EC25_Series_Hardware_Design 61 / 134
The following figure shows a reference design of wireless connectivity interfaces with Quectel FC20
module.
COEX_UART_RX
137
DI
LTE/WLAN & BT coexistence signal
1.8 V power domain.
Cannot be pulled up
before startup.
If unused, keep it open.
COEX_UART_TX
138
DO
LTE/WLAN & BT coexistence signal
1.8 V power domain.
Cannot be pulled up
before startup.
If unused, keep it open.
WLAN_SLP_CLK
118
DO
WLAN sleep clock
BT Part
BT_RTS
37
DI
BT UART request to send
1.8 V power domain
BT_TXD
38
DO
BT UART transmit data
1.8 V power domain
BT_RXD
39
DI
BT UART receive data
1.8 V power domain
BT_CTS
40
DO
BT UART clear to send
1.8 V power domain.
Cannot be pulled up
before startup.
If unused, keep it open.
PCM_IN
1)
24
DI
PCM data input
1.8 V power domain
PCM_OUT
1)
25
DO
PCM data output
1.8 V power domain
PCM_SYNC
1)
26
IO
PCM data frame synchronization
signal
1.8 V power domain
PCM_CLK
1)
27
IO
PCM data bit clock
1.8 V power domain
BT_EN
139
DO
BT function control via FC20
module.
1.8 V power domain
Active high.