si4021 Silicon Laboratories, si4021 Datasheet - Page 5

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

PACKAGE PIN DEFINITIONS, EEPROM MODE
Pin type key: D=digital, A=analog, S=supply, I=input, O=output, IO=input/output
EEPROM Mode Pin Assignment
Pin
10
11
12
13
14
15
16
1
2
3
4
5
6
7
8
9
Name
nSEL
nLBD
MOD
SDO
VDD
SCK
VSS
RFN
RFP
FSK
PB1
PB2
PB3
PB4
XTL
SDI
Type
AIO
DO
DO
DO
AO
AO
DO
DI
DI
DI
DI
DI
DI
DI
S
S
Function
Data input of serial control interface
Clock output of serial control interface
Chip select output 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)
Data output of serial control interface
Crystal connection (other terminal of crystal to VSS)
Ground reference
Connect to logic low (EEPROM mode)
Power amplifier output (open collector)
Power amplifier output (open collector)
Low battery voltage detector output (active low)
Positive supply voltage
Not used, connect to VDD or VSS
IA4221
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