EMIF06-MSD02N16 Datasheet, PDF (4/12 Pages) STMicroelectronics – 6-line IPAD™, EMI filter and ESD protection

Application information
2
Application information
EMIF06-MSD02N16
The EMIF06-mSD02N16 is a dedicated interface device for micro SD card/T-Flash card in
mobile phones. The device provides:
● ESD protection
● EMI filterering
● Pull-up resistors
● Card detection circuit
2.1
ESD protection
Each pin is connected to a TVS diode able to withstand 12 kV on all pins except on
DATx_In, CMD_In and CLK_In.
2.2
EMI filtering
DATx, CMD and CLK lines are immunized against EMI radiations thanks to pi-filters. To
avoid any degradation of the signal integrity at high frequency, the total line capacitance
stays lower than 20 pF making the device compatible with a clock frequency up to 52 MHz.
2.3
Pull-up resistors
As recommended by the SD Specifications (Part 1 Physical Layer Version 2.00), all the data
lines DATx and the CMD line must be pulled-up with resistors of 10 to 100 kΩ to avoid bus
floating not only in SD 4-bit mode but also in SD 1-bit and SPI mode.
For the EMIF06-MSD02N16 device the pull-up resistor value has been fixed at 90 kΩ. This
value makes the EMIF06-MSD02N16 compatible with most of the level shifters that may be
used in the circuit including auto direction-sensing translators known to exhibit a weak
current output.
2.4
Card detection circuit
The EMIF06-mSD02N16 provides the flexibility to use either mechanical card detection with
a dedicated pin connected to the memory card slot or the electrical card detection using the
internal pull resistor of DAT3 of the micro SD card/T-Flash card.
In case of mechanical card detection, the user must add a pull-up on the circuit connected to
the CD (Card Detect) of the micro-SD/T-Flash slot as shown in Figure 8.
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