6-34 Keysight B2900 User’s Guide, Edition 5
Function Details
Over Temperature Protection
Over Temperature Protection
The over temperature protection is effective for preventing damage to a channel
from over temperature. If B2900 is used in an environment over 30 C, channel
outputs are limited to the value less than the maximum value. If a channel output
reaches the limit, all channels automatically and immediately set the output to 0 V
and set the output switch to off. And the causal channel is locked automatically.
To unlock the channel, the self-test must be performed. If the self-test does not
report any problem, you can use the channel soon. For performing the self-test, see
“Self-test” on page 3-11.
The maximum output for the condition over 30 C is less than the maximum output
for the specification condition of 23 C 5 C. The channel output limit is given by
the following formula.
DC
MAX
( [ ( P
CS
+ 30 - T
AMB
) - |V
OAB
I
B
| ] / |V
OAP
I
P
| )
2
100
The parameters are described below.
•DC
MAX
: Allowable maximum duty ratio in %, or 0 for DC bias output
•P
CS
: Maximum power, 64 W
•T
AMB
: Ambient temperature, in C
•V
OAB
= 250 V, for |I
B
| 105 mA
V
OAB
= 39 V, for |I
B
| > 105 mA and |V
B
| > 6V
V
OAB
= 21 V, for |I
B
| > 105 mA and |V
B
| 6V
V
B
: Pulse base voltage setting value or DC bias voltage setting value, in V
•I
B
: Current at pulse base or DC current, in A
•V
OAP
= 250 V, for |I
P
| 105 mA
V
OAP
= 39 V, for |I
P
| > 105 mA and |V
P
| > 6V
V
OAP
= 21 V, for |I
P
| > 105 mA and |V
P
| 6V
V
P
: Pulse peak voltage setting value, in V
•I
P
: Current at pulse peak, in A