Keithley 2657A, Reference Manual, Page: 205 / 805

Section 4: Theory of operation Model 2657A High Power System SourceMeter® Instrument Reference Manual
4-4 2657A-901-01 Rev. B/December 2012
Operating boundaries
Source or sink
Depending on how it is programmed and what is connected to the output (load or source), the
instrument can operate in any of the four quadrants. The four quadrants of operation are shown in the
continuous operating boundaries figures. When operating in the first (I) or third (III) quadrant, the
instrument is operating as a source (V and I have the same polarity). As a source, the instrument is
delivering power to a load.
Figure 68: Four quadrants of operation
When operating in the second (II) or fourth (IV) quadrant, the instrument is operating as a sink (V and
I have opposite polarity). As a sink, it is dissipating power rather than sourcing it. An external source
or an energy storage device, such as a capacitor or battery, can force operation in the sink region.
Continuous power operating boundaries
The general operating boundaries for Model 2657A continuous power output are shown in the
following figure. For derating factors, see the
General power equation (on page 4-3). In this drawing,
the illustrated voltage and current magnitudes are nominal values. Also note that the boundaries are
not drawn to scale.
Figure 69: Model 2657A continuous power operating boundaries
-V
+V
+I
-I
(IV)
Sink
(III)
Source
(I)
Source
Energy storage DUT
Energy storage DUT
(II)
Sink
Energy storage DUT
Energy storage DUT
≤ 30 °C
T
amb
+I
-I
-V +V
(IV)
Sink
(III)
Source
(I)
Source
(II)
Sink
+120 mA
+60 mA
+20 mA
-60 mA
-120 mA
-3 kV -1.5 kV +1.5 kV +3 kV
-20 mA