Interfacing SD-Cards with their host computers almost always requires a voltage-level translator. This is because most of these memory cards operate at signal levels between 1.7 and 3.6 VDC, while their hosts operate with nominal supply levels varying from 1.1 to 1.95 VDC. Until now, bidirectional level translators for SD 3.0 memory cards were WLCSP devices with 20 bumps or solder balls. The new translator for SD 3.0 memory cards, from Nexperia, is a WLCSP device with 16 bumps. Its footprint is 40% smaller than the 20-bump types. The new device, NXS0506UP, supports multiple data and clock transfer rates for signaling levels that the SD 3.0 standard specifies. Moreover, this includes the SDR104 mode for ultra-high speeds.

While shifting the voltage levels between the memory card and the I/O lines of the host device, the new translator operates at clock frequencies of up to 208 MHz and handles data rates up to 104 Mbps. To automatically detect whether data and control signals should move from the host to the memory card (card write mode) or from the memory card to the host (card read mode), the device uses its integrated auto-directional control.

Apart from the auto-directional control, Nexperia has substantially reduced the BOM cost of their NXS0506UP device by integrating the pull-up and pull-down resistors. These resistors are essential in establishing the voltage levels at the chip IO lines, and discrete resistors push up the BOM cost. In addition, the input/output driver stages of the device have inbuilt EMI filters that help to reduce interference. Moreover, Nexperia has provided robust ESD protection, according to the IEC 61000-4-2 standard, on all the side pins of the memory card. While the 16-bump WLCSP has a physical measurement of just 1.45 x 1.45 x 0.45 mm, its operating temperature ranges from -40 °C to +85 °C.

The NXS0506UP SD card voltage level translator is useful for consumer devices like automotive systems, medical devices, notebook PCs, digital cameras, and smartphones. The SD 3.0 standard compatible level translator is a bidirectional dual supply device with auto-direction control. Nexperia has designed the card for interfacing cards operating from 1.7 to 3.6 VDC levels to hosts with a nominal supply voltage between 1.1 to 1.95 VDC. Apart from the SD 3.0 standard, the device also supports the SDR12, SDR25, DDR50, SDR50, SDR104, and the SD 2.0 standards at default speeds of 25 MHz and high speeds of 50 MHz. The device offers built-in protection from ESD and EMI conforming to the IEC 61000-4-2, level 4 standard.

There are several benefits to using the NXS0506UP SD card voltage level translator. The primary benefit is it supports a maximum clock rate of 208 MHz. It translates voltage levels for default and high-speed modes. It has auto-direction sensing for data and controls. The power consumption is low, while the device integrates pull-up and pull-down resistors. The integrated EMI filter suppresses higher harmonics at digital IOs. Buffers at the IO lines help to keep ESD stresses away with the zero-clamping concept. The 16-bump WLCSP package offers a pitch of 0.35 mm.