Huawei EM820W manual Certification Test, 8SIM IO requirements, Vcc Vcc+0.3, ESD protection

HUAWEI EM820W HSPA+ PC Embedded Module
Hardware Guide			Description of the Application Interfaces
	Table 3-8SIM IO requirements
	IO	Minimum		Maximum
	VIL	0		0.4
	VIH	0.7Vcc		Vcc
	VOL	–0.3		0.2 Vcc
	VOH	0.7 Vcc		Vcc+0.3

The VOLmax of 0.45 V for the output is specified at an output current of 3 mA whereas the

VILmax of 0.4 V for the SIM IO input is specified at an input current of 1 mA. With the smaller current drive, the output voltage would be driven lower than the stated maximum value.

zESD protection

Since the SIM is a CMOS device, ESD protection devices should be placed near the SIM connector to provide protection before connecting to the module. In addition, all the SIM interface signals should be bypassed with a 10 pF capacitor.

The used ESD device (PESD3V3L5UY, NXP) in Figure 3-2 is a low capacitance 5-fold ESD protection diode arrays in SOT363 package.

zClock frequency

The SIM must support clock frequencies between 1 MHz and 4 MHz. (The Mini Card can be programmed to generate a clock of 1.625 MHz, 2.6 MHz, or 3.25 MHz.)

zRouting recommendations

The SIM interface signals consist of four signals that are UIM_PWR, UIM_RST, UIM_CLK, and UIM_DATA (UIM_Vpp is neither connected nor used in many applications). Due to the relatively low clock frequencies involved, the concern is not the degradation of the SIM signals but that of routing of the SIM interface signals through areas considered to be of high risk for RF noise coupling (crosstalk and RF contamination), which can desensitize the radio circuitry. The general guidelines that should be followed are listed as follows:

−It is recommended that these signals should be routed over a continuous ground plane.

−SIM interface signals should not be routed near high transient signals (power supply chokes and DC/DC switching FETs).

−Prevent routing of these signals near output connectors.

−Keep SIM interface signals isolated from other signals. 2x width spacing (1.5x min) between SIM interface signals and all other signal routing is recommended.

3.6.3Certification Test

Using test equipment simulates a (U)SIM card to test U(SIM) protocol in GCF or PTCRB test, If some test. If you encounter some issues during SIM/USIM test, please contact Huawei for more details.

Issue 01 (2010-12-31)	Huawei Proprietary and Confidential	13
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