Specifications
L506 Hardware Design 
Copyright©  Shanghai  Mobiletek  Communication  Ltd                                                              45 
L506
LED
VLED
R2
R1
 Figure 3-22 Status indicator reference circuit 
Note: R1, R2 value according to the voltage VLED and LED working current. 
Table 3-21 NETLIGHT status 
Net Status 
Module working status  
Always on 
Searching Network/Call Connect 
200ms ON, 200ms OFF 
Data Transmit 
800ms ON, 800ms OFF 
Registered network 
OFF 
Power off / Sleep 
Note: NETLIGHT output low level as “ON”, and high level as “OFF”. 
3.12 SD card interface 
3.12.1 Pin descriptions 
L506provides  a  4-bit  SD/MMC  interface  with  clock  rate  up  to  52MHz.  The  operation  voltage  of 
MMC/SD interface is 2.85V with SD/MMC memory cards up to 128G(FAT4), which is compatible 
with SDIO Card Specification (version 3.0), Secure Digital (Physical Layer Specification, version 3.0) 
and Multimedia Card Host Specification MMC (version 4.4) 
  Table 3-22 SD characteristics 
Symbol 
Parameter 
Min. 
Typ. 
Max. 
Unit 
VDD_EXT** 
LDO output 
- 
2.85 
- 
V 
VIH 
High-level input 
voltage 
0.625*VDD_
EXT 
- 
VDD_EXT+0.3 
V 
VIL 
Low-level input 
voltage 
-0.3 
0 
0.25*VDD_EX
T 
V 










