
VCC  | 
SCL  | VCC  | 
SDA  | 
  | 
SCHEMATIC:
mounted.  | R1  | 
They are not  | R2  | 
  | GND  | 
SEL  | 
  | 
  | IC1  | ||
  | 
  | 
  | 
  | ||
  | 
  | 2  | P0.0  | P2.0  | |
  | 
  | 1  | |||
  | 
  | P0.1  | P2.1  | ||
SJ1  | 
  | 28  | |||
  | P0.2  | P2.2  | |||
NRES 1  | 2  | 27  | |||
P0.3  | P2.3  | ||||
  | TX  | 26  | |||
  | P0.4  | P2.4  | |||
  | RX  | 25  | |||
  | P0.5  | P2.5  | |||
IRQ  | 
  | 24  | |||
  | P0.6  | P2.6  | |||
  | 
  | 23  | |||
  | 
  | P0.7  | P2.7  | ||
  | 
  | 
  | |||
SCK  | 
  | 22  | P1.0  | P3.0/C2D  | |
MISO  | 
  | 21  | |||
  | P1.1  | 
  | |||
MOSI  | 
  | 20  | 
  | ||
  | P1.2  | /RST/C2CK  | |||
  | 
  | 19  | |||
  | 
  | 
  | 
  | ||
14
13
12
11
10
9
8
7
6
5
SW1
6  | ON  | 1  | 1  | 
5  | 
  | 2  | 2  | 
4  | 
  | 3  | |
  | 3  | ||
  | 
  | 
  | 
GND
R4
R5 820
820
![]()
D1
R6
820
Yellow
D3
Green
D2
Red
MOSI
SCK
SEL
MISO
IRQ
FFS
IC2
1  | SDI  | NINT/VDI  | 
  | ||
2  | SCK  | ARSSI  | 
  | ||
3  | NSEL  | VDD  | 
  | ||
4  | SDO  | RF1  | 
  | ||
5  | NIRQ  | RF2  | 
  | 
6FSK/DATA/NFFS VSS
16INT/VDI ![]()
15
 ARSSI
14![]()
VCC
13
12
11  | GND  | 
C8  | 
  | 
  | 
  | GND  | 
  | 
  | |||
L1  | 
  | |||
  | 
  | |||
C9  | 
  | X1  | ||
  | 
  | |||
50 OHM
FFS  | 18  | P1.3  | 
  | |
P1.4  | VDD  | |||
FFIT  | 17  | |||
P1.5  | 
  | |||
INT/VDI  | 16  | 
  | ||
P1.6  | 
  | |||
ARSSI  | 15  | 
  | ||
P1.7  | GND  | |||
  | 
  | 
4 ![]()
VCC
  | C1  | R7  | NRES  | 
  | 
  | 
  | |
3  | 100nF  | 1k  | 
  | 
  | 
  | ||
  | 
  | 
  | 
FFIT
7DCLK/CFIL/FFIT NRES
8  | CLK  | XTL/REF  | 
  | 
10NRES
9
C2  | Q1  | 
GND  | 
L3  | 
C8051F311
It is not mounted.  | 
GND GND
IA4420
Only rev. C or above!
4,7nF
 10MHz
 3 TX
2RX
1
SERIAL
GND
3![]()
2
1
DEBUG
GND
GND GND
  | 
  | VCC  | 
C5  | C6  | C7  | 
1uF  | 100pF  | 10pF  | 
1  | 
  | 
  | 
  | 
  | 
  | VCC  | 3,3V  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
POWER  | 
  | 
  | 
  | 
  | IC3  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | |
2  | 
  | 
  | 
  | 1 IN OUT  | 5  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | |
3  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | C3  | 
  | 2  | GND  | 
  | C4  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
BATTERY  | 100k  | 
  | 
  | 
  | 
  | R9  | 4,7k R10  | 4,7k R11  | 4,7k  | 
  | 
  | |||
2,2uFR8  | 3  | ON POK  | 4  | 2,2uF  | 3  | 
  | 
  | |||||||
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | ||
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | ||
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | LCD  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 2  | 
  | 
  | 
  | 1  | VLCD  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | R3 10k  | 1  | 
  | 
  | 
  | 
  | 2  | |
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | VSS  | |||
  | 
  | GND  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 3  | |
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | VDD  | ||
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | SDA  | 
  | 
  | 
  | 4  | |
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | SDA  | ||
  | GND  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 5  | |
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | POR  | ||
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | GND  | SCL  | 
  | 
  | 
  | 6  | |
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | SCL  | |||
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | |
BT21605
GND
GND
REPEATER DEMO
Fig 9 . IA4420 Transceiver Repeater Demo Schematic
12