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
10510

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

lsusb -vvd 1df7:2500 Bus 002 Device 003: ID 1df7:2500 Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 2.00 bDeviceClass 255 Vendor Specific Class bDeviceSubClass 255 Vendor Specific Subclass bDeviceProtocol 255 Vendor Specific Protocol bMaxPacketSize0 64 idVendor 0x1df7 idProduct 0x2500 bcdDevice 2.00 iManufacturer 0 iProduct 0 iSerial 0 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 66 bNumInterfaces 1 bConfigurationValue 1 iConfiguration 0 bmAttributes 0x80 (Bus Powered) MaxPower 400mA Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 bNumEndpoints 0 bInterfaceClass 255 Vendor Specific Class bInterfaceSubClass 255 Vendor Specific Subclass bInterfaceProtocol 255 Vendor Specific Protocol iInterface 0 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 1 bNumEndpoints 1 bInterfaceClass 255 Vendor Specific Class bInterfaceSubClass 255 Vendor Specific Subclass bInterfaceProtocol 255 Vendor Specific Protocol iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x81 EP 1 IN bmAttributes 1 Transfer Type Isochronous Synch Type None Usage Type Data wMaxPacketSize 0x1400 3x 1024 bytes bInterval 1 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 2 bNumEndpoints 1 bInterfaceClass 255 Vendor Specific Class bInterfaceSubClass 255 Vendor Specific Subclass bInterfaceProtocol 255 Vendor Specific Protocol iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x81 EP 1 IN bmAttributes 1 Transfer Type Isochronous Synch Type None Usage Type Data wMaxPacketSize 0x0400 1x 1024 bytes bInterval 1 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 3 bNumEndpoints 1 bInterfaceClass 255 Vendor Specific Class bInterfaceSubClass 255 Vendor Specific Subclass bInterfaceProtocol 255 Vendor Specific Protocol iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x81 EP 1 IN bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0200 1x 512 bytes bInterval 0 Device Qualifier (for other device speed): bLength 10 bDescriptorType 6 bcdUSB 2.00 bDeviceClass 255 Vendor Specific Class bDeviceSubClass 255 Vendor Specific Subclass bDeviceProtocol 255 Vendor Specific Protocol bMaxPacketSize0 64 bNumConfigurations 1 Device Status: 0x0000 (Bus Powered)

Pictures