Naked hardware #13: Logitec LDT-1S310U/J

Logitec LDT-1S310U/J teardown!

It is Mirics MSi3101 reference design and nothing more. 

Logitec LDT-1S310U/J

Key components:

Mirics MSi2500
Mirics MSi001

General info

First  of all, check my earlier post about Mirics MSi3101 Linux driver as that device is similar from the hardware point of view. Device is sold as a 1seg ISDB-T TV tuner for Japan market. 1seg aka One Seg is mobile digital television standard used in few countries like Japan and Brazil. Only thing that makes this device as 1seg receiver is bundled software. As a SDR based DTV solution it is possible to use same hardware for receiving other standards just using another software.

Device has no eeprom, which means USB ID is the one defined by chipset itself 1df7:2500 (chipset default ID). That means it is compatible with all software released for Mirics MSi3101.

Initial Linux support for that device has gone to the Kernel 3.12 as a staging quality.

Hardware internals

PCB top side
All relevant components, MSi2500 and MSi001, could be found from that side of PCB. 24.000 MHz crystal is also visible. It offers reference clock for both chips.

PCB is rather tiny, only 37 x 17 mm. MSi2500 is integrated USB interface ADC. MSi001 is silicon RF tuner. I am not going to chip details now as I have done it earlier, just look my older blog posts about MSi3101 for more detailed information.

Antenna connector looks like typical MCX but it is not. Type of that connector is unknown for me but, fortunately package contains antenna pigtail cable having standard F female on the other end. There is also two small antennas bundled. Other antenna is quite unusual small telescope without a cable and another is typical mini-magnet type, coming along with almost every of these DTV sticks.

PCB has some printings:
LWE 88 94V-0

PCB bottom side is almost empty

PCB bottom side 

Nothing to say.

PCB printings:
ISDBT2036 Ver 1.0

Connected antennas

MSi001 antenna inputs

VHF (pins 9, 10), BAND3 (pins 3, 4) and BAND45 (pins 6, 7) antennas are connected. AM (pins 37, 38 & 39, 40) and LBAND (pins 24, 25) inputs are not connected. That limits actual frequency range to 50 - 960MHz.

It is possible to connect those unconnected inputs but it is not very trivial as chip is very small. Likely microscope soldering station is needed.

USB interface

IDLE current drain without a driver: 32mA


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