Agilent Technologies 6625A - Manual (Page 47)

Output Connections and Operating Information 47
Figure 4-3 shows the current sink characteristics lower voltages in greater detail. The area in quadrant 4 illustrates the
reverse polarity diode characteristics of each output. Do not operate any output with reverse-voltage currents that are
greater than the maximum rating of the output.
Figure 4-3. Typical Downprogramming Characteristic Below 2.0 V
Operating Ranges
Notice in Figure 4-2, there are four overlapping areas in quadrant one for both the 25 watt and 50 watt outputs. The Low
Range Voltage and Low Range Current ranges are higher precision than the High Range Voltage and High Range Current
ranges. The voltage and current ranges can be set independently (see page 73). If the high resolution range is programmed,
attempting to program values outside this range will result in a number range error.
The 50 watt output (Figure 4-2B) is different from the 25 watt output (Figure 4-2A), in that there is a power limiting
boundary at 1 amp in the High Voltage/High Current range. As a result, the 50 watt output can be set to no more than 1.03
amps at voltage settings above 16.16 volts, and vice versa.
Setting parameters of voltage or current beyond this power limit boundary, but within the High Voltage/High Current range
will cause the other parameter (voltage or current) to automatically be scaled down to the power limiting boundary (see
pages 71 and 73).
The voltage and current programming resolution of the outputs is affected by the setting of the range. The voltage of the 25
watt output, when programmed to the Low Voltage Range, has a voltage programming resolution of 460
µ
V. When
programmed above 7 volts, the High Voltage Range must be selected resulting in a programming resolution of 3.2 mV.
The current of the 25 watt output, when programmed to the High Current Range, has a current programming resolution of 1
µ
A. When programming above 15 mA, the High Current Range must be selected, resulting in a programming resolution of
33
µ
A.
The voltage of the 50 watt output, when programmed to the High Voltage Range, has a voltage programming resolution of
1 mV. When programming above 16.16 volts, the high range must be selected, resulting in a programming resolution of 3.2
mV.
The current of the 50 watt output, when programmed to the High Current Range, has a current programming resolution of
13
µ
A. When programmed above 200 mA, the High Current Range must be selected, resulting in a programming resolution
of 131
µ
A.
The readback range of the outputs is not programmable, and is selected automatically by the power supply.