In voltage mode, the "rungs" or arms of the ladder are switched between Vref and ground and the output is taken from the end of the ladder. The voltage output is the advantage in this mode, as is the constant output impedance, which eases the neutralizing of any amplifier on the output node. Additionally, the switches switch the arms of the ladder between a low impedance Vref connection and low impedance ground so capacitive glitch currents tend not to flow in the load. On the other hand, the switches must operate over a wide voltage range (Vref to ground), which is difficult from a design and manufacturing viewpoint. In addition to this, the reference input impedance varies widely with code, so that the reference input must be driven from a very low impedance. Also, the gain of the DAC cannot be adjusted by a resistor in series with the Vref terminal.