General Description

The i7520 is a combined burst mode laser driver and limiting amplifier for use within fiber optic modules for FTTx applications. Used with a low cost serial EEPROM or microcontroller it forms a complete PON diplexer silicon solution.

The transmit block includes a high frequency modulator and a bias current generator. The bias current can be controlled either by a fast settling APC loop or in open loop mode which uses a temperature lookup table.

The receiver includes a limiting amplifier with programmable bandwidth. A Signal Detect/Loss Off Signal function is implemented using the input signal modulation amplitude with user selectable threshold and hysteresis.

Operating with a 3.3V supply and rated from -40 to +85°C ambient, the i7520 is housed in a 32pin, 5x5mm, RoHS compliant, QFN package.

特性 Features

● Burst-Mode common anode laser driver with up to 90mA modulation and 100mA bias current

● 4ns output switching in Burst Mode operation.

● Closed or open loop bias mode with temperature lookup table.

● Temperature compensated modulation current setting stored in look up table

● Limiting amplifier with programmable low pass filter and output swing

● Device settings stored in external 2k EEPROM or MCU

● Support TX-SD function

● Lock APC Loop in 1 burst signal

● Support SPI interface and I2C interface

● Integrate APD voltage control

● Full compliance with SFF8472 and SFP MSA

Applications

GEPON/GPON ONU Transmitters

Passive Optical Network (PON) Transmitters

Fiber-to-the-Home(FTTH) and Fiber-to-the-Premises(FTTP) Broadband Access Systems