Tektronix Keithley 2601B-PULSE Reference Manual

Model 2601B-PULSE System SourceMeter Instrument Reference Manual Section 7: Theory of operation
2601B-PULSE-901-01A April 2020 7-3
To calculate the maximum duty cycle (DC
MAX
), use the general power equation shown below. The
general power equation describes how much power an instrument can source and sink before the
total power cannot be fully dissipated by the cooling system of the instrument. This equation
incorporates all the factors that can influence the power dissipated by the instrument.
V
OA
The instrument output amplifier voltage. This constant can be found in the table below.
V
P
The voltage level the instrument is attempting to force while at the pulse level.
When operating in quadrants 1 or 3 (sourcing power), the sign of this voltage must be
positive when used in the power equations.
When operating in quadrants 2 or 4 (sinking power), the sign of this voltage must be
negative when used in the power equations.
I
P
The current flowing through the instrument channel while at the pulse level.
V
B
The voltage level the instrument is attempting to force while at the bias level.
When operating in quadrants 1 or 3 (sourcing power), the sign of this voltage must be
positive when used in the power equations.
When operating in quadrants 2 or 4 (sinking power), the sign of this voltage must be
negative when used in the power equations.
I
B
The current flowing through the instrument channel while at the bias level.
P
CS
The maximum power generated in an instrument channel that can be properly dissipated
by the instrument cooling system measured in watts. For the 2601B-PULSE, this constant
equals 56.
P
DER
= T
AMB
- 30
This factor represents the number of watts the instrument is derated when operating in
environments above 30 °C. The maximum output power is reduced by 1 W per degree C
above 30 °C.
P
DER
is 0 when the ambient temperature is below 30 °C.
T
AMB
The ambient temperature of the instrument operating environment.
The following equation applies to sinking and sourcing power simultaneously. If a duty cycle less than
100% is required to avoid overheating, the maximum on-time must be less than 10 seconds.
When attempting to determine the maximum duty cycle, where the off state will be 0 V or 0 A:
▪ I
B
is 0
▪ I
P
and V
P
are the current and voltage levels when the instrument is on
Maximum duty cycle equation constants
Constant
100 mV range
1 V range
6 V range
40 V range
V
OA
18
18
18
55

Tektronix Keithley 2601B-PULSE Specifications

General

Brand	Tektronix
Model	Keithley 2601B-PULSE
Category	Measuring Instruments
Language	English