7
hivolt.de
GmbH & Co. KG
Oehleckerring
40
∙
D-22419
Hamburg
∙
Germany
∙
+49 40 537122-0
∙
+49 40 537122-99
∙
∙
www.hivolt.de
Two jumpers (W3, W4) are provided on each amplifier module to configure differential output mode:
W3
1-2 Master
Default
2-3 Slave
W4
1-2 Master
Default
2-3 Slave
3.5
DISABLE
The high voltage amplifier channels can be remotely switched off through the
DISABLE
input. The
signal is available through connector
X1 INTERLOCK
on the HAR42-4 rear panel. It is TTL-compatible.
A LOW-signal turns on all amplifier outputs. In case of open input or HIGH signal, the amplifier
outputs are forced to 0V. During disable the internal high voltage sources are not turned off. The
DISABLE
input can be used to turn on and off the amplifier outputs relatively fast.
If the
DISABLE
input is not needed, a wire jumper can be installed between
DISABLE (X1.4)
and
GND
(X1.5)
to turn on the amplifiers permanently.
The
DISABLE
input is not suitable to achieve a safe state at the amplifier output. It must not be used
for safety relevant purposes.
3.6
Loading Conditions
The amplifiers are designed to drive capacitive and resistive-capacitive loads. The output is stable
even with large capacitive loads. In case of larger load capacitances overshoot of the output may
occur.
The slew rate that can be achieved on the output depends on the load capacitance. The effective load
capacitance C
L
consists of the amplifier’s internal output capacitance (ca. 80pF), capacitance of the
output cable (a typical coaxial cable: ca. 100pF/m) and capacitance of the connected load.
The output stage can provide peak currents (I
OP
) of > ±7.5mA
P
for ca. 1s. The maximum static output
current is +5mA and -5mA.
Achievable slew rate:
SR = I
O
/ C
L
[V/s]
.
If the average positive or negative output current exceeds 5mA (HA2B5-S) or 3mA (HA3B3-S) the
amplifier shuts down with
Overload
.
If the maximum slew rate is exceeded, distortions occur in the output signals. In principle, the
amplifier should thus only be controlled by input signals that satisfy the achievable slew rate for a
given load. However, dynamic override of the inputs (e.g. control by square wave signals) is harmless.
The edges of the output waveform are nearly linear then with a slight overshoot.
Large capacitive loads driven by high frequency signals may result in a DC-offset superimposed on the
output voltage. This occurs if the final value of the desired output voltage can not be reached
periodically.
