TTL-232R-3V3-PCB 参数 Datasheet PDF下载

Document Reference No.: FT_000065

TTL-232R-PCB TTL TO USB SERIAL CONVERTER PCB Datasheet Version 1.01

Clearance No.: FTDI# 54

4.1

TTL-232R-PCB Signal Descriptions

Name

GND

CTS#

VCC

TXD

RXD

RTS#

Type

GND

Input

Output

Output

Input

Output

Description

Device ground supply pin.

Clear to Send Control input / Handshake signal.

+5V output,

Transmit Asynchronous Data output.

Receive Asynchronous Data input.

Request To Send Control Output / Handshake signal.

Table 4.1 TTL-232R-PCB Signal Descriptions

4.2

TTL-232R-PCB +5V/+3.3V Selection

Selection of whether the UART signal are +3.3V levels or +5V levels is done using resistors. The following

table gives details of what resistors are required for the two different voltage levels. Note that the VCC

output signal will always drive at +5V.

Resistor

R1

Fitted

Not Fitted

Resistor

R2

Not Fitted

Fitted

Description

UART signals are +5V level signals

UART signals are +3.3V level signals

Table 4.2 UART Signal Level Selection

4.3

TTL-232R-PCB Electrical Parameters

Parameter

Description

Minimum

Typical

Maximum

Units

Conditions

Dependant on the USB

VCC

Output Power Voltage

4.25

5.0

5.25

V

port that the TTL-232R-

PCB is connected to

I

O

T

Output Power Current

Operating Temperature

Range

-

-40

75

+85

mA

o

C

Table 4.3 TTL-232R-PCB I/O Operating Parameters

Parameter

Voh

Vol

Vin

VHys

Description

Output Voltage High

Output Voltage Low

Input Switching Threshold

Input Switching Hysteresis

Minimum

3.2

0.3

1.0

20

Typical

4.1

0.4

1.2

25

Maximum

4.9

0.6

1.5

30

Units

V

V

V

mV

Conditions

I source = 6mA

I sink = 6mA

Table 4.4 TTL-232R-PCB I/O Pin Characteristics (+5V level signals)

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