Copyright © 2010 Future Technology Devices International Limited

14

Document Reference No.: FT_000136

USB-COM485-PLUS2 Datasheet

Version 1.3

Clearance No.: FTDI#104

4 Electrical details

4.1 USB

Parameter

Description

Minimum

Typical

Maximum

Units

Conditions

USB_VCC

Input Power Voltage*

4.25

5.0*

5.25

V

*Present when USB

cable is attached and

USB Host or Hub

powered.

Icc

USB current***

30

50

mA

***Does not include

power supplied to

external device

connected to pin 9 of

both ports.

Table 4.1 - USB Electrical Details

4.2 RS485

Parameter

Description

Minimum

Typical

Maximum

Units

Conditions

Vtrans

Transmitter output

voltage swing

2

V

RL = 50R CL = 50pF

Vrec

Receiver input voltage

range

-7

+12

V

RL = 50R CL = 50pF

ESD HBM

N/A

±15

KV

For all RS-485 Inputs

and Outputs pin

Table 4.2 – RS485 Electrical Details

4.3 Power Output

The USB-COM485-PLUS2 provides +5V DC for an external device that requires power on pin9 of DB9.

The maximum allowable current is 500mA, including the circuitry of the USB-COM485-PLUS2 itself. Up to

450mA may be used by the external device. The +5V output is only enabled when the USB interface is

not in suspend.

Parameter

Description

Minimum

Typical

Maximum

Units

Conditions

IO

Output Power Current

0

250*

mA

USB interface is not in

SUSPEND.

*This is total current

between the 2 ports.

Table 4.3 - Power Output for USB-COM485-PLUS2