Specifications

Rev 1 Dec.10 Proprietary and Confidential - Specifications subject to change 75
Each digital output has a maximum current of 15mA.
5.8.2 Electrical characteristics
Tabl e 5- 1 9 describes the power rail signal’s electrical characteristics.
5.8.3 Application notes
Caution: This section is under review and subject to change.
5.8.3.1 VREF_1V8—1.8 V logic reference
Note: VREF_1V8 is only available when the AirPrime SL808X Embedded Module is ON.
The following are good design practices to consider:
• Total current draw must be < 1 mA.
• If used as a reference only (host provides its own pull-up voltage rail), a
100  resistor should be put in series.
• Depending on the host PCB trace length for this signal, PCB provision for
decoupling capacitors may be required.
5.9 Reserved
The AirPrime SL808X Embedded Module includes pins that may not be used in
your host design. These pins should be handled in the following ways:
• Pins marked ‘Reserved - DNC’—Leave these pins untouched. (See Ta bl e 4- 2
on page 34 for pin assignments/names.)
• Unused inputs/outputs on specific interfaces (USB, USIM, etc.)—Leave as
no-connects.
62 W_DISABLE_N Wireless disable
63 WAKE_N Wake Host Interface
60 LED_FLASH LED driver
a. USIM interface may be configured as 1.8 V or 3.0V.
Table 5-19: VREF_1V8 signal electrical characteristics
Parameter Minimum Typical Maximum Unit
VREF_1V8 Output voltage 1.76 1.8 1.94 V
Output current 1 mA
Table 5-18: 1.8 V connector pins (Continued)
Pin Signal name Description