FT4232HL-1000 FTDI [Future Technology Devices International Ltd.], FT4232HL-1000 Datasheet - Page 18

• Manufacturer Part Number: FT4232HL-1000
• Description: QUAD HIGH SPEED USB TO MULTIPURPOSE UART/MPSSE IC
• Manufacturer: FTDI [Future Technology Devices International Ltd.]

4.3.2 RS422 Configuration
Figure 4.2 illustrates how the FT4232H can be configured as a dual RS422 interface. The FT4232H can
have all 4 channels connected as RS422, but only channel A and channel C are shown for clarity.
Figure 4.2 Dual RS422 Configuration
In this case both channel A and channel C are configured as UART operating at TTL levels. The Sipex
SP491 is used as a level converter to convert the TTL level signals from the FT4232H to RS422 levels.
The PWREN# signal is used to power down the level shifters such that they operate in a low quiescent
current when the USB interface is in suspend mode.
FT4232H
SUSPEND#
Copyright © 2010 Future Technology Devices International Limited
PWREN#
DTR#
DSR#
DCD#
RTS#
CTS#
RXD
TXD
DSR#
DCD#
RTS#
CTS#
DTR#
RI#
TXD
RXD
RI#
FT4232H QUAD HIGH SPEED USB TO MULTIPURPOSE UART/MPSSE IC
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16
17
18
19
21
22
23
24
38
39
40
41
43
44
45
46
4
5
3
2
4
5
3
2
4
5
3
2
4
5
3
2
6
6
6
6
D
D
D
D
R
R
7
7
14
14
R
R
7
7
14
14
VCC
VCC
VCC
SP491
SP491
VCC
SP491
SP491
10
11
10
11
9
12
9
12
10
11
10
11
9
12
9
12
Document No.: FT_000060
RS422 Channel A
120R
120R
RS422 Channel C
Clearance No.: FTDI#78
120R
120R
Datasheet Version 2.09
RXDM_A
DB9-M
TXDM_A
RTSM_A
CTSM_A
TXDP_A
RXDP_A
RTSP_A
CTSP_A
RXDM_C
RTSM_C
DB9-M
TXDM_C
RXDP_C
CTSM_C
GND
TXDP_C
RTSP_C
CTSP_C
GND
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