User Guide

LM960 HW Design Guide
1VV0301485 Rev. 15 Page 69 of 88 2020-08-13
9. APPLICATION GUIDE
Debug of the LM960 Module in Production
To test and debug the LM960 module integration, we strongly recommend to add several
test pins on the host PCB for the following purposes:
 Checking the connection between the LM960 itself and the application
 Testing the performance of the module by connecting it with an external computer
Depending on the customer application, these test pins include, but are not limited to the
following signals:
 SYSTEM_RESET_N, W_DISABLE_N, PCIE_WAKE_N
 VBATT, GND
 VREG_L6_1P8
 USB_D-, USB_D+
 USB_SS_TX_M, USB_SS_TX_P, USB_SS_RX_M, USB_SS_RX_P
In addition, the following signals are also recommended (but not mandatory):
 WAN_LED_N
 GPIO_01, GPIO_02, GPIO_03, GPIO_04, GPIO_05, GPIO_06, GPIO_07,
GPIO_08
Bypass Capacitor on Power Supplies
When a sudden voltage step is asserted to or a cut from the power supplies, the steep
transition causes effects such as overshoot and undershoot. This abrupt voltage transition
can affect the device causing it to not operate or to malfunction.
Bypass capacitors are needed to alleviate this behavior, which can appear differently
depending on the various applications. Customers must pay special attention to this issue
when they design their application board.
The length and width of the power lines must be considered carefully, and capacitors
value must be selected accordingly.
The capacitor will also prevent power supplies ripple and the switching noise caused in
TDMA systems, such as GSM.
Most important, a suitable bypass capacitor must be mounted on the following lines on the
application board:
 VBATT
Recommended values are: