Page 15
© 2009 Active Research Limited
Specifications
Parameter
Conditions
Min.
Max.
Unit
Supply
Supply voltage
From USB port
4.75
5.25
V
Supply current drawn from USB port
Supply voltage = 5v (no load)
40
46
mA
Supply voltage = 5v (output shorted)
75
80
mA
RS485 Transceiver Input / Output
Input voltage b/-
Logical ‘1’
2.0
15.0
V
Logical ‘0’
-0.3
0.5
V
Input current
-
1.0
mA
Differential input voltage
Required level for data to be detected
-0.2
0.2
V
Output voltage b/- and ground
(under no load)
Logical ‘1’
0.0
0.5
V
Logical ‘0’
4.5
5.0
V
Output current at max load of 100 ohm
At maximum load, differential drive
voltage reduces to 1.4v
-
14
mA
Output short circuit current (note 1)
Due to short circuit protection
50
55
mA
Galvanic isolation
From USB ground
1500
V
Static discharge protection
Yes
PC Communication settings
Baud rate
Both input & output Baud rates are set
by the PC software settings
300
115200
bps
General
Ambient temperature
-20
+70
°C
Table 2 – USG-1-485 specifications
All specifications are taken with reference to an ambient temperature (T
A
) of +2
5
°C.
Note:
1. Short circuit may be applied indefinitely. The RS485 transceiver input / output may be short-circuited directly to a
30 volt battery supply without damage. A maximum current of 50mA will flow due to “polyfuse” auto-resetting fuse
technology being used.
Summary of Contents for USG-1-B-485
Page 2: ......
