
Industrial Environment
Switching Regulators, PCB & Chassis
PSC-Family
Edition 2/96 - Melcher AG
4 - 55
MELCHER
The Power Partners.
4.2
Standards and Approvals
All Melcher power supplies are subject to manufacturing
surveillance in accordance with ISO 9001 standards.
All units are UL recognized as per UL 1950, UL 1012 and
CAN/CSA C22.2 No. 234-M90.
Cleaning Agents
In order to avoid possible damage, any penetration of
cleaning fluids is to be prevented, since the power supplies
are not hermetically sealed.
Protection Degree
The protection degree is defined by IP 20.
Standard Features
i Inhibit
Note: With open i-input, output is enabled (
Uo = on)
The inhibit input allows the switching regulators to be disa-
bled via a control signal. In systems with several units, this
feature can be used, for example, to control the activation
sequence of the regulators by a logic signal (TTL, C-MOS,
etc.).
An output voltage overshoot will not occur when the units
are switched on or off.
Fig. 3
Output response as a function of inhibit signal
Data
Table 3: Inhibit characteristics
Characteristics
Conditions
min
typ
max
Unit
Uinh
Inhibit input voltage to keep
Uo = on
Ui min...Ui max
–50
+0.8
V DC
regulator output voltage...
Uo = off
TC min...TC max
+2.4
+50
t r
Switch-on time after inhibit command
Ui = Ui nom
5ms
t f
Switch-off time after inhibit command
RL = Uo nom /Io nom
10
Ii off
Input current when inhibited
Io = 0, Ui = Ui nom
10
mA
Fig. 2
Definition of Iinh and Uinh
Fig. 4
Inhibit current Iinh versus inhibit voltage Uinh
4
2
0
-50 -40
20
40
-30
0
-20 -10
10
30
50
5
3
1
I inh [mA]
U inh [V]
U o on
U o off
U
inh
=
0.8
V
U
inh
=
2.4
V
Vi+
Gi–
Go–
i
Vo+
Iinh
Uinh
1
0.1
0
Uo/Uo nom
U inh
tr
tf
t
1