LM940 Hardware Design Guide
1VV0301352 Rev. 18
Page 57 of 75
2022-01-04
Not Subject to NDA
•
100uF for VBATT
Please note that capacitance mainly depends on the conditions of their application board.
Generally, additional capacitance is required when the power line is longer.
And if customers use the fast power down function, then more bypass capacitors should
be mounted on the application board.
EMC Recommendations
EMC protection on the pins in the table below should be designed by application side
according to the customer’s requirement.
Pin
Signal
I/O
Function
Type
Comment
USB HS 2.0 Communication Port
38
USB_D+
I/O
USB 2.0 Data Plus
Analog
36
USB_D-
I/O
USB 2.0 Data Minus
Analog
USB SS 3.0 Communication Port
33
USB_SS_RX_P
I
USB 3.0 super-speed receive
–
plus
Analog
31
USB_SS_RX_M
I
USB 3.0 super-speed receive
–
minus
Analog
25
USB_SS_TX_P
O
USB 3.0 super-speed transmit
–
plus
Analog
23
USB_SS_TX_M
O
USB 3.0 super-speed transmit
–
minus Analog
SIM Card Interface 1
14
SIMRST1
O
Reset output to an external UIM1 card
1.8 / 2.85V
12
SIMCLK1
O
Clock output to an external UIM1 card
1.8 / 2.85V
10
SIMIO1
I/O
Data connection with an external UIM1
card
1.8 / 2.85V
8
SIMVCC1
O
Supply output for an external UIM1
card
1.8 / 2.85V
Power
SIM Card Interface 2
*
SIMRST2
O
Reset output to an external UIM2 card
1.8 / 2.85V
See note
17
SIMCLK2
O
Clock output to an external UIM2 card
1.8 / 2.85V
19
SIMIO2
I/O
Data connection with an external UIM2
card
1.8 / 2.85V
*
SIMVCC2
O
Supply output for an external UIM2
card
1.8 / 2.85V
Power
See note
Digital I/O (GPIOs)