Two years ago, Semtech launched the GN25L98. The laser driver contains a boost chip. Since the chip optimizes the stability of the laser driver, it has attracted customers' attention as soon as it was launched. Therefore, in 2019, in response to the faster network bandwidth, based on the previous IC architecture, GN28L96 will be further introduced in the design of 10G EPON & XGSPON FTTh ONU/ONT BoB.
PON application transmission mode of GN28L96
– Downstream: OLT can send data to any GN28L96 at any time. In the upstream direction, the OLT can only receive data from one GN25L98 at the same time. If two GN28L96s send data to the OLT at the same time, the OLT cannot receive the data correctly (ONU transmission conflict).
– Uplink: Divide the fiber occupation into time periods according to a certain length of time. In each time period, only one GN28L96 can occupy the fiber to send data to the OLT, and the remaining GN28L96 control the laser to be turned off. The OLT specifies the time period for GN28L96 to send data by sending control data packets.
In addition, EYEMAX technology for 10G bandwidth is added, which can optimize the eye diagram at a faster network speed.
Semtech GN28L96 only needs to provide free development software interface for R&D and use. Customers can easily adjust the register through computer visualization through the USB to I2C adapter board interface provided by Semtech (as shown below)
It can easily adjust the optical power required for transmission and the functions of the matting pen, etc.
Therefore, this can save the trouble of initial development, and provide software source code in the later stage for reference by software personnel in developing production programs.
Semtech also provides design circuits for customer reference, reduces the burden of R&D personnel, and provides layout review support
(1) TX full temperature range eye diagram
IC MCU 8BIT 768B OTP 28SDIP
IC MCU 32BIT 256KB FLASH 100TQFP
IC MCU 32BIT 128KB FLASH 64LQFP
IC MCU 16BIT 64KB FLASH 28UQFN