Texas Instruments TRS3232RGTEVM, User Manual

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4 Schematic and Layout
The TRS3232RGTEVM has simple connections to all necessary pins of the TRS3232 transceiver device, and
jumpers where necessary to provide flexibility for device. The TRS3232RGTEVM provides test points for all
RS-232 (TX1, RTS1, RX1, CTS1) and logic (TX2, RTS2, RX2, CTS2) communication lines. Additionally test
points of GND, VCC, and charge pump output voltage are available for probing and evaluation.
4.1 Schematic
The schematic is shown in Figure 4-1 . The function of each jumper and test point is listed in Table 4-1 .
GND
GND
VCC
VCC
VCC
GND
16V
0.1uF
C2
16V
0.1uF
C4
16V
0.1uF
C1
16V
0.1uF
C3
0
R3
0
R4
0
R5
0
R6
0
R7
10.0k
R1
10.0k
R2
CTS1
CTS1
TX1
TX1
RTS1
RTS1
RX1
RX1
RX2
RX2
CTS2
CTS2
TX2
TX2
RTS2
RTS2
V-
V+
1 2
3 4
5 6
7 8
9 10
11 12
13 14
15 16
J2
C1-
1
C2+
2
C2-
3
V-
4
DOUT2
5
RIN2
6
ROUT2
7
TIN2
8
TIN1
9
ROUT1
10
RIN1
11
DOUT1
12
GND
13
VCC
14
V+
15
C1+
16
PAD
17
TRS3232RGT
U0
GND
1
2
3
4
5
6
7
8
9
1
1
1
0
J1
618009231121
10V
1uF
C5
25V
1uF
C6
Figure 4-1. TRS3232RGTEVM schematic
Table 4-1. Jumpers and Test Points
Connection Type Description
J1 9-pin connector Female DB9 connector to connect to PC
J2 16-pin jumper Used for supply and TTL signal
V+ Test point Charge pump positive output
V- Test point Charge pump negative output
Power and logic signal go through the J1 connector. Table 4-2 lists each pin’s connection.
Table 4-2. J1 pin connection
Connection Type Description
1 NC Not connected
2 Output RX1, pin 12 of transceiver
3 Input TX1, pin 11 of transceiver
4 Loopback Connected to pin 6
5 GND Ground
6 Loopback Connected to pin 4
7 Input RTS1, pin 6 of transceiver
8 Output CST1, pin 5 of transceiver
9 NC Not connected
The female DB9 port ( Figure 4-2 ) provides access to the TRS3232RGT device through a standard RS-232
pinout. The TRS3232RGT female port is DCE to mate with a computer's male DTE port. The pin names are
counterintuitive on the DCE side. For example the RX pin on EVM is connected to a driver and TX connects to a
receiver. The pin connection is listed in
Table 4-3 . The reason pins 4 and 6 are shorted together by a 0 Ω resistor
is to loopback the unused handshaking lines.
Schematic and Layout www.ti.com
4 TRS3232RGTEVM Evaluation Module SLLU320 – NOVEMBER 2020
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