In semi-conductor components, more particularly memory components such as DRAMs (Dynamic Random Access Memory and/or dynamic read/write memory) an internal voltage level used inside the component can differ from an external voltage level used outside the component.
In particular, an internally used voltage level can, for instance, be smaller than the externally used voltage level, for instance, an internally used voltage level can amount to 1.5 V or 1.8 V and the voltage level used externally for instance to 2.5 V or 2.9 V.
The reason for this can, for instance, be because the external voltage supply is subject to relatively strong fluctuations, and therefore needs to be converted to an internal voltage (which is subject only to relatively minor fluctuations and regulated to a particular constant value) by a voltage regulator, which allows the component to be operated in a fault-free way. The use of voltage regulators can however cause a voltage drop, which causes the voltage level used inside the component to be lower than the voltage level used out-side. An internal voltage level lower than that used externally can, for instance, have the advantage of reducing the power dissipation in the semi-conductor component.
Alternatively or additionally, an internal voltage level that is “turned up” or “boosted” in relation to the external voltage level can, for instance, also be used.
If necessary, several different internal voltage levels can also be used in the semi-conductor component (for example 1.5 V and 1.8 V, etc.).
If a different, more particularly a lower voltage level, than externally, is used inside the component (or several other, in particular, lower voltage levels), the signals generated inside the semi-conductor component must first—before being emitted to the outside—by a so-called voltage converter be converted to a corresponding—more particularly a higher—voltage.
Such a voltage converter can, for instance, contain an amplifier circuit, consisting of cross-coupled p- and/or n-channel field effect transistors.
With the aid of the amplifier circuit, internal, low-voltage signals generated in the component can be converted—although subject to certain delay times—into corresponding high-voltage signals.
The delay times occurring with conventional voltage converters can however be relatively large.
Furthermore, with conventional voltage converters it is only possible to attain a certain—limited—differential in levels between output signals (particularly at a higher level) and input signals (particularly at a lower level).