Memory Card Interface from STMicroelectronics for Portable Applications

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.