TN-3: Interfacing with UltraVolt High Voltage Power Supplies
High Power C Series & High Power 8C–30C Series
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In this Technical Note, we provide tips for interfacing with the interconnection pins and leads of the UltraVolt High Power C and High Power 8C–30C Series. This document augments the data sheets for each of the series. Complete product data sheets can be found here.
A few remarks about these UltraVolt series:The High Power C Series delivers 0 to125 volts through 0 to 6 kV
at power levels of 60-watts, 125-watts, or 250-watts maximum.
The High Power 8C–30C Series deliver 0 to 8 kV through 0 to
30 kV at power levels of 60-watts or 125-watts maximum.
AN OVERVIEW OF THE CONNECTIONS
Pins 1 and 8 — Input Power
Ground Return: These pins are the Input Power Ground for the 60-watt and 125-watt models. 250-watt units have a separate power connector to handle the higher input currents. Refer to the specific data sheets for details.
Pins 2, 9 and 10 (HPC 60W or 125W) – Positive
Power Input: These pins are the Positive Power Input for the 60-watt
and 125-watt 1/8C through 6C units. The input voltage range is 23Vdc
to 30Vdc; however, these power supplies will perform over a wider range
of input voltage with proper de-rating. See the data sheet for de-rating
Pins 2 and 9 (HP 8C–30C) – Positive
Power Input: These pins are the input power for 8C through 30C
units. The input voltage range is 23Vdc to 30Vdc; however, these power
supplies will perform over a wider range of input voltages with proper
de-rating. See the data sheet for de-rating information.
Pins 2, 9, and 10 (HPC 250W) – No
Connection: These pins are not used in the 250-watt High
Power C Series. All 250-watt units have an additional 4-pin connector
to handle the higher input current. Refer to the data sheet for
Pin 3 – Iout Monitor: This
pin serves as the Iout Monitor
pin, as depicted in Figure 1. Scale factors vary and are unique to each
model. The HV Multiplier in each high-voltage power supply is grounded
through the RSense resistor, as shown in
Figure 1. The HV Feedback resistors and the HV Test Point resistors are
returned to ground and are seen by the power supply as an internal load.
This internal load is the source of an offset on the Iout monitor
that must be accounted for when making output current measurements. Refer
to the individual models’ data sheets for details.
Figure 1. Current Monitoring Circuitry — a
Pin 4 – Enable/Disable: The
enable function is the same for all models. A HIGH signal enables and
a LOW signal disables the output. If pin 4 is left open, the power supply
defaults to an enabled state. The data sheet has detailed information
on logic levels.
Pin 5 – Signal Ground
Return: The signal ground
should be used as the reference point for both the remote adjust
and the monitors. Do
not return the HV load here. If input current is allowed
to flow through the signal return path, offsets and errors may
occur in the control and monitoring functions.
Pin 6 – Remote Adjust
Input: The remote adjust
pin allows the high-voltage power supply to be programmed from
0% output voltage to 107.5% of rated output voltage. Positive power
supplies are scaled so 4.64V on the remote adjust will result in
100% of output voltage, while 5.00V will provide 107.5% of full
voltage. The remote adjust pin has an input impedance of 1.1MΩ;
this resistor to ground is provided to program the power supply
to zero output if the control pin is left open. See Figure 3A.
A negative power supply has the
opposite sense on the control voltage (see Figure 2 below). 0V on
the remote adjust programs the power supply for 107.5% of rated voltage
and 0.32V provides 100% output. Driving the remote adjust pin to
5.00V on a negative power supply will program zero output voltage.
A 1.1MΩ resistor pull-up
to the Vref pin internally provides zero output voltage if the control
pin is left open. See Figure 3B.
Figure 2. Remote Adjust Inputs — Negative and Positive High Voltage Supplies
Figure 3. Remote Adjust Inputs
Pin 7 – +5VDC Reference
Output: A +5VDC reference
voltage is provided for programming the power supply. The reference
voltage has an output impedance of 464Ω. See the data sheet
of your model for characteristics.
Pins 11, 12, 13 – No
Pin 14 –
Eout Monitor (Output voltage monitor): The Eout Monitor is accomplished with a high-voltage divider resistor
set. The scale factor is model dependent and will be either a 100:1
or 1000:1 ratio. The divider resistor set is designed to be properly
scaled with a 10MΩ input-impedance
meter connected to the circuit. It is possible to shunt the lower
divider resistor to create different scale factors. The resistor
values are available in the model-specific data sheets.
Pins 15 and 16 – High
Voltage Ground Return: Internally,
the Power Ground, the HV Ground, and the Signal Ground are common.
The high-voltage load return should be connected here.
Pins 19 and 20 – Positive
Power Input: These pins
are the input power for 250-watt units due to the higher input
current at this power level. The input voltage range is 23Vdc to
30Vdc; however, these power supplies will perform over a wider
range of input voltages with proper de-rating. See the data sheet
for de-rating information.
Pins 21 and 22 –Input
Power Ground Return: These
pins are the input power return for 250-watt units and must be
used as power ground for the higher input currents.
*** END OF TECH NOTE TN-3 ***