SI4420-D1-FT Datasheet, PDF (4/33 Pages) List of Unclassifed Manufacturers – Si4420 Universal ISM Band FSK Transceiver

PACKAGE PIN DEFINITIONS
Pin type key: D=digital, A=analog, S=supply, I=input, O=output, IO=input/output
Si4420
Pin Name Type Function
1
SDI
DI
Data input of the serial control interface
2
SCK DI
Clock input of the serial control interface
3
nSEL DI
Chip select input of the serial control interface (active low)
4
SDO DO Serial data output with bus hold (tri-state)
5
nIRQ DO Interrupt request output (active low)
FSK DI
Transmit FSK data input
6
DATA DO Received data output (FIFO not used)
nFFS DI
FIFO select input (active low) In FIFO mode, when bit ef is set in Configuration Setting Command
DLCK DO Received data clock output (Digital filter used, FIFO not used)
7
CFIL AIO External data filter capacitor connection (Analog filter used)
FFIT
DO
FIFO interrupt (active high) Number of the bits in the RX FIFO that reach the preprogrammed limit
In FIFO mode, when bit ef is set in Configuration Setting Command
8
CLK DO Microcontroller clock output
9
XTL
AIO Crystal connection (the other terminal of crystal to VSS) or external reference input
REF AIO External reference input. Use 33 pF series coupling capacitor
10
nRES DIO Open drain reset output with internal pull-up and input buffer (active low)
11
VSS S
Ground reference voltage
12
RF2
AIO RF differential signal input/output
13
RF1
AIO RF differential signal input/output
14
VDD S
Positive supply voltage
15
ARSSI AO Analog RSSI output
16
nINT DI
Interrupt input (active low)
VDI
DO Valid data indicator output
Note: The actual mode of the multipurpose pins (pin 6 and 7) is determined by the TX/RX data I/O settings of the transceiver.
4