Application information

EMIF06-MSD02N16

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Application information

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 k

Ω 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 k

Ω. 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.