HUAWEI ME909 Series LTE LGA Module
Hardware Guide
Description of the Application Interfaces
Issue V0.3 (2013-05-21)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
24
Figure 3-3
Recommended power circuit of ME909 module
When the system power restarts, a discharge circuit is recommended to make sure
the power voltage drops below 1.8 V and stays for 100 ms at least. This is very
important. If POWER_ON_OFF is asserted when the VBAT is between 1.8 V to 3.2 V,
the module may enter an unexpected status.
3.3.3
Output Power Supply Interface
Output power supply interface is VCC_EXT1 and SIM_VCC.
Through the output power supply interface, the ME909 module can supply 1.8 V
power externally with an output current of 10 mA (typical value) for external level
conversion or other applications.
If the ME909 module is in sleep mode, the output power supply interface is in the low
power consumption state (< 500
μA). If the ME909 module is in power down mode,
the output power supply is in the disabled state.
Through the SIM_VCC power supply interface, the ME909 module can supply 1.8 V
or 2.85 V power to USIM card. The transient current can reach 200 mA, so special
attention on PCB design should be taken at the host side.
3.4 Signal Control Interface
3.4.1
Overview
The signal control part of the interface in the ME909 module consists of the following:
Power-on/off (POWER_ON_OFF) pin
System reset (RESIN_N) pin
WAKEUP_IN Signal (WAKEUP_IN) pin
WAKEUP_OUT Signal (WAKEUP_OUT) pin
SLEEP_STATUS Signal (SLEEP_STATUS) pin
LED control signal(LED_MODE) pin
Table 3-3 lists the pins on the signal control interface.
Module
(DCE)
VBAT
VBAT
100 nF
10 μF
+
220
μF
+
220
μF
+
220
μF
+
220
μF
+
220
μF