5G Module Series
RM505Q-AE Hardware Design
RM505Q-AE_Hardware_Design 31 / 79
“*” means under development.
RM505Q-AE supports (U)SIM card hot-plug via the USIM_DET pin. With a normally closed (U)SIM card
connector, the USIM_DET is normally short-circuited to ground when a (U)SIM card is not inserted, and
the USIM_DET will change from low to high voltage level when a (U)SIM card is inserted. The rising edge
indicates an insertion of the (U)SIM card. When the (U)SIM card is removed, USIM_DET will change from
high to low voltage level. This falling edge indicates a removal of the (U)SIM card.
Normally Closed (U)SIM Card Connector:
⚫
When the (U)SIM is absent, CD is short-circuited to ground and USIM_DET is at low voltage level.
⚫
When the (U)SIM is inserted, CD is open from ground and USIM_DET is at high voltage level.
The following figure shows a reference design of (U)SIM interface with a normally closed (U)SIM card
connector.
Module
(U)SIM Card
Connector
USIM_DET
USIM_DATA
USIM_CLK
RST
CLK
CD
IO
USIM_VDD
USIM_VDD
USIM_RST
VCC
GND
VPP
GND
TVS
Note:
All these resistors, capacitors and TVS should be close to (U)SIM card connector in PCB layout.
10-20k
22R
22R
22R
3
3
p
F
3
3
p
F
3
3
p
F
100 nF
Figure 14: Reference Circuit for Normally Closed (U)SIM Card Connector
Normally Open (U)SIM Card Connector:
⚫
When the (U)SIM is absent, CD1 is open from CD2 and USIM_DET is at low voltage level.
⚫
When the (U)SIM is inserted, CD1 is short-circuited to 1.8 V and USIM_DET is at high voltage level.
The following figure shows a reference design of (U)SIM interface with a normally open (NO) (U)SIM card
connector.
NOTE