si4021 Silicon Laboratories, si4021 Datasheet - Page 3

• Manufacturer Part Number: si4021
• Description: Si4021 Universal Ism Band Fsk Transmitter
• Manufacturer: Silicon Laboratories

PACKAGE PIN DEFINITIONS, MICROCONTROLLER MODE
Pin type key: D=digital, A=analog, S=supply, I=input, O=output, IO=input/output
Microcontroller Mode Pin Assignment
Pin
10
11
12
13
14
15
16
1
2
3
4
5
6
7
8
9
Name
nSEL
MOD
nIRQ
SCK
VSS
RFN
RFP
VDD
PB1
PB2
PB3
PB4
CLK
FSK
XTL
SDI
Type
AIO
DO
DO
AO
AO
DI
DI
DI
DI
DI
DI
DI
DI
DI
S
S
Function
Data input of serial control interface
Clock input of serial control interface
Chip select input of serial control interface (active low)
Push-button input #1 (active low with internal pull-up resistor)
Push-button input #2 (active low with internal pull-up resistor)
Push-button input #3 (active low with internal pull-up resistor)
Push-button input #4 (active low with internal pull-up resistor)
Crystal connection (other terminal of crystal to VSS)
Ground reference
Power amplifier output (open collector)
Power amplifier output (open collector)
Positive supply voltage
Serial data input for FSK modulation
Microcontroller clock (1 MHz-10 MHz)
Connect to logic high (microcontroller mode)
Interrupt request output for microcontroller (active low) and status read output
IA4221
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