Nexperia , the critical semiconductor specialist, has announced the latest addition to its family of voltage level converters, the NXT4557GU and NXT4556UP. These devices enable seamless connectivity of next-generation low-voltage mobile baseband processors with their subscribers' identity module (SIM) cards.
As processor geometries advance into single-digit nanometer nodes, the core voltage of advanced SoCs is decreasing. This development increases the need for voltage converters to connect the SoC to other standard process devices and I/O ports, such as legacy Class B and Class C SIM cards.
The NXT4557GU and NXT4556UP dual power converters support voltage levels between 1.08V and 1.98V on the host processor side and 1.62V to 3.6V on the SIM card side. These operating ranges make these devices compatible with legacy Class B (3.0 V ± 10%) and Class C (1.8 V ± 10%) voltage levels, while maintaining compatibility with the voltage levels, which will be used per future SIM card interface standards (1.2 V ± 10%).
The NXT4557GU and NXT4556UP feature bidirectional IO and unidirectional RESET and clock channels and an intelligent ONE SHOT that enables very low channel propagation delays. These devices have a low operating current of 8 µA with a standby current of just 1 µA to help maximize the battery life of mobile devices. Built-in pull-up resistors help further reduce standby power consumption while reducing overall system BOM space and cost.
The NXT4557GU has an enable (EN) pin and is housed in a lead-free XQFN10 package, while the NXT4556UP is auto-enabled and comes in an ultra-small 0.35mm pitch WLCSP9 package.
“In the event of a system failure or accidental battery removal, the SIM card power supply quickly discharges and there is no time left for the interface device to perform the shutdown sequence,” said Vikram Singh Parihar, senior product manager at Nexperia. “Nexperia’s NXT4557GU and NXT4556UP take care of this clumsy shutdown by implementing orderly shutdown of signals and helping to avoid any improper recording and data corruption.”
