Specifications

605xA and 606xB: Electronic Loads Below 3 Volts

Question: Is there a way I can use an 606xB or 605xA Electronic load below 3 volts without derating?

Answer: Yes. Use a boost supply in series with the UUT. The load will now meet all its specs with no derating,

because it always operates above 3 volts (refer to the figure below).

The boost supply can be a low-cost fixed output 3 V or 5 V supply with a current rating at least as high as the

maximum peak load current needed. The 6641A (8 V, 20 A), 6651A (8 V, 50 A), 6671A (8 V, 220 A), or 6681A (8

V, 580 A) are all excellent choices. The voltage setting of a programmable boost supply should be set to 3 volts, and

the current limit set to full scale. Select a boost power supply with low peak-peak (p-p) ripple and noise. The

constant current load will compensate for low frequency p-p ripple and noise below a few kHz, but high frequency

ripple and noise from the boost will appear across the UUT.

DC Boost

Supply

UUT

-S

A COM

EXT PRG

FLT

PORT

D COM

Boost supply operates in

constant voltage at ~3.5 volts;

must be able to handle UUT's

I(max) discharge current

Unit under test must be attached

to the negative terminal of the

Load for the remote voltage sensing

to function correctly.

Electronic Load

Operated in constant voltage

or constant current

LOAD