 connectivityZONE Products for the week of November 5, 2007
STMicroelectronics Says…
Five-Function Memory Card Interface Saves Space and Cost in Portable Applications
One compact chip provides level shifting EMI/ESD protection and LDO voltage regulator for SD/MMC card interfaces
STMicroelectronics has announced a tiny, highly-integrated chip -- produced using the company’s world-leading IPAD (Integrated Passive and Active Devices) technology -- which provides five essential functions required by memory card interfaces in mobile phones, GPS navigation devices, digital cameras and a broad range of other consumer and industrial products that use removable Secure Digital (SD) protocol cards. The new flip-chip EMIF06-SD02F3 memory-card transceiver integrates signal conditioning, bidirectional level shifting, ESD (electrostatic discharge) protection, EMI (electromagnetic interference) filtering, and a 2.9V voltage regulator.
Integration of these circuits into a single monolithic chip increases system reliability and saves more than 75% of the board area required by a typical discrete solution. The EMIF06-SD02F3 requires less than 7 square millimeters of board space, compared to approximately 30 square millimeters to provide the same functions with discrete components, also simplifying the design and layout of the application.
The chip is compliant with standard and high-speed SD standards, and with MiniSD, MMC and uSD/TransFlash. It provides a high level of ESD protection to exposed external memory card slots, efficient EMI filtering to protect data lines against RF interference, and pull-up and pull-down resistors to prevent floating data lines. ESD protection on the card-side pins meets the stringent IEC61000-4-2 Level 4 standard, 15kV air discharge. The 800MHz to 3GHz EMI filter achieves over 20dB attenuation at 1GHz.
In addition, six high-speed bidirectional level shifters, designed for 50MHz operation and with 3ns typical propagation delay, enable the interfacing of 2.9V memory cards with 1.8V host processors. A maximum channel-to-channel skew of 1.5ns ensures data transmission integrity, and the drivers are optimized for low-power applications with quiescent off-current of 1-microamp.
Power for the memory card is provided through an on-chip 2.9V low drop-out (LDO) CMOS voltage regulator, with 200mA current capability and an input voltage range of 3.1V to 5V. The drop-out voltage is 100mV maximum with a 200mA load. A switch-off control pin, with fast 30us turn-on time, helps minimize a product’s power consumption and extend battery life, and the regulator includes thermal shut-down, under-voltage lock-out and short-circuit protection.
EN-Genius Says…
Every once in a while I come a cross a no-brainer product -- a chip, component or piece of software that does not require the usual lengthy deliberative process before you decide to use it in your next design. This STMicro integrated SD memory interface chip is one of those rare no-brainer products because of the reduction in cost, complexity and space requirements it provides to any mobile product packing a SD, MiniSD, or MMC interface. By applying its analog smarts and proprietary processes, STMicro has come up with a part that should enjoy wild popularity, and one that most competitors will find difficult or impossibly tough to imitate. This is one example of why, contrary to popular belief, having your own fab can be a big strategic advantage.
It’s no small trick to integrate a bunch of elements that have such diverse functions and materials requirements but STMicro used a variant of their bipolar process to do just that. The result is a chip that combines a level shifter, a low-pass EMI filter, and an LDO supply, -- plus another 10-15 passives you’d normally have to plunk down to terminate the data, address and control lines. About the only thing the informative release above neglects to mention about the EMIF06-SD02F3 is that it has logic that detects when memory is not present so that its LDO, level shifter, and other sections can go to standby for additional power savings.
 I could not get many details of the process that the STMicro Catania, Sicily, facility uses to produce logic elements, power devices, and high-voltage diodes (they’re IEC 6100-4-3 compliant) on the same die except that they have borrowed some tricks from their digital line to enable embedding of the logic they need. Since some of the capacitors on the chip are probably quite sizable, I’ll speculate that they are using something a bit more exotic than simple oxide in their dielectric layers but I could not get any confirmation of this, let alone the juicy details on just how they do it. But, however they do it, the result is that using their chips should give you around 75% savings in PCB area for a typical application.
The ambitious volumes stated in the pricing below reflects the size of the markets STMicro is aiming for. Beyond all the smart phones, picture phones and multimedia-till-you-drop phones whose innards will clearly benefit from the space savings, there are lots of other consumer applications where this handy little I/O chip will find a warm welcome. Expect to see the EMIF06-SD02F3 tucked nearby the expansion slots of HPCs, cameras, gaming systems, MP3 players, and portable nav systems in the near future.
Surprisingly, STMicro also says they’ve had lots of interest in less-obvious non-handheld applications, such as desktop PCs and printers.
Even if all it did was save space and cost in the memory slots of handheld devices STMicro would have a winner here but this little chip is even bigger news because of the popularity that SD and mini-SD memory interfaces enjoying as an expansion port for other kinds of portable I/O such as Wi-Fi and WiMAX radios. STMicro says that it was not designed to support non-memory applications but I suspect it will find its way there anyway.
The EMIF06-SD02F3 is available in a Pb-free, 24-bump, 400-micron pitch flip-chip, and is in volume production. It is priced at $1.10 for up to 1 million piece lots, and $0.95 for 1 to 5 million pieces.
Data Sheet
|
