1
1. Minimum System Reference Circuit
Supply 2.8V~3.6V power VCC
Ground all GND pins of the module
Connect RF_IN signal to antenna, note the 50 Ω impedance match on the circuit
Figure 1 Minimum System Reference Circuit
GND
nRESET
RXD
TXD
L1
68nH
GND
C2
100pF
C1
100nF
R2
0
R5
0
GND
C10
100nF
VBCKP
VBCKP
:
1.4V~3.6V
VCC
:
2.8V~3.6V
GND
GND
C4
10 uF
VCC
GND
C3
100nF
J1
Activ e Ant
1
2
3
4
5
+3V
TXD
RXD
A1
UM220-IV-M0
nREST
9
NC2
13
TIMEPULSE
4
NC1
5
NC3
15
VCC_RF
14
GND
10
RF_IN
11
GND
12
VCC_IO
7
NC6
18
NC4
16
NC5
17
TXD
2
RXD
3
V_BCKP
6
VCC
8
GND
1
GND
C7
100nF
C9
100nF
C8
100nF
C5
100nF
U1
MAX
DIN1
11
DIN2
10
ROUT1
12
ROUT2
9
DOUT1
14
DOUT2
7
RIN1
13
RIN2
8
V+
2
C1+
1
C1-
3
C2+
4
C2-
5
V-
6
VCC
16
GND
15
GND
GND
GND
C6
100nF
GND
GND
GND
J2
DB9
5
9
4
8
3
7
2
6
1
10
11
R3
100
R4
100
R1
1K
Active Low