Murata WIT2420 - Reference Design

Murata Electronics Corporation 33 6/2/2021
7.5. Reference Design
WIT2410 Interface
+C2
1 uF
DCD
DTR_SLEEP_3.3V
VCC 3.3V
CTS_3.3V
Optional pullups to keep
RTS and DTR asserted
when left unconnected
RXD_3.3V
TXD_5V
RXD
TXD_3.3V
+
C4
1 uF
If using a 5.0V converter use the
following circuit for TXD,DTR,RTS
R1
6.8k
12
U5
MAX3238
28
25
1
3
16
5
6
7
10
12
24
23
22
19
17
21
20
18
9
11
8
26
27
4
13
14
15
2
C1+
C1-
C2+
C2-
R1OUTB
T1OUT
T2OUT
T3OUT
T4OUT
T5OUT
T1IN
T2IN
T3IN
T4IN
T5IN
R1OUT
R2OUT
R3OUT
R2IN
R3IN
R1IN
VCC
V+
V-
FORCEON
FORCEOFF
INVALID
GND
RTS
R2
6.8k
12
D1
MBR0520L
12
CTS
RS232 Interface
TXD
+
C3
1 uF
R1
10k
1 2
RTS_3.3V
DTR
TXD_3.3V
DCD_3.3V
R2
15k
1 2
C5
0.1uF
12
VCC 3.3V
C1
0.22uF
12