Rohde & Schwarz Debuts Linear Power Supplies for Testing Applications

The R&S NGA 100 series from Rohde and Schwarz (R&S) is not an attempt to derail switched-mode power supplies (SMPS). Rather, the new devices take advantage of the capabilities that linears offer for generating the very precise voltages that can often be so necessary for testing purposes.

Dual and single output members of the R&S NGA 100 series. Image courtesy of R&S

 

The Members of the R&S NGA100 Series

The R&S NGA101 and the R&S NGA141 both feature one output. Voltages and currents can be adjusted for a maximum of 40 watts output

• The R&S NGA101 can supply up to 40 watts of output power composed of voltages of up to 35 volts and currents of up to 6 amps.
• For the R&S NGA141, the maximum voltage and currents are 100 volts and 2 amps.

The R&S NGA102 and the R&S NGA142 both feature two outputs. Voltages and currents can be adjusted for a maximum of 80 watts output

• The R&S NGA102 can supply up to 80 watts of output power composed of voltages of up to 35 volts and currents of up to 6 amps. The outputs can be combined in series for a maximum of 70 volts or in parallel for a 12 amp maximum.
• For the R&S NGA142, the 80 watt maximum can be supplied with maximum voltage and currents are 100 volts and 2 amps. Combined in series, there is a 200 volt ceiling, and combined in parallel, as much as 4 amps is possible.

It is important to note that the dual output NGA102 and NGA142, the two outputs are completely independent, and neither are connected to chassis ground.

 

A Linear Design

The NGA100 features a linear design throughout its output circuits. This choice enables a higher level of performance as compared to what today’s SMPS devices can provide, allowing for a readback resolution of 1mV/100 µA. For currents under 200 mA, resolution is 1 µA, exactly what is needed to test the low current levels of ICs in standby or sleep mode. In active mode, the unit has the dynamic range for power and current spikes.

 

Sensing and Control

The NGA100 offers logging voltage and current values for analysis, with a sample rate of up to up to 10 samples per second. Operators can specify sequences of voltage/current settings at intervals down to 10 ms. For control of the unit and for transmitting data, Ethernet and USB are provided as standard. Options include external triggering via digital I/Os and communication via WLAN.

A remote sensing function allows measurement to be recorded at the device under test. This will compensate for any cable losses that might be apparent at the 1mV level that the NGA100 can function at.

 

Electrical Specifications

Voltage Ripple and Noise measured between 20 Hz to 20 MHz

• NGA101 and the NGA102:  less than 0.5 mVRMS, 10 mV (P-P)
• NGA141 and the NGA142:  less than 1.5 mVRMS, 20 mV (P-P)

Voltage Load Regulation for a load change between 10 and 90%

• NGA101 and the NGA102:   ±(0.01% of output + 5 mV offset) 
• NGA141 and the NGA142:   ±(0.01% of output + 10 mv offset)
• Current Ripple and Noise: measured between 20 Hz to 20 MHz, is less than 500 μA (RMS) 
• Current Load Regulation: ±(0.01% of output + offset of 5 mA)