1. General description

The TZA3046 is a transimpedance amplifier with Automatic Gain Control (AGC), designed
to be used in Fiber Channel/Gigabit Ethernet (FC/GE) fiber optic links. It amplifies the
current generated by a photo detector (PIN diode or avalanche photodiode) and converts
it to a differential output voltage. It offers a current mirror of average photo current for
RSSI monitoring to be used in SFF-8472 compliant modules.
The low noise characteristics makes it suitable for FC/GE applications, but also for
FTTx applications.

2. Features

nLow equivalent input noise current, typically 126 nA (RMS)
nWide dynamic range, typically 2.5 µA to 1.7 mA (p-p)
nDifferential transimpedance of 7.5 kΩ (typical)
nBandwidth from DC to 1050 MHz (typical)
nDifferential outputs
nOn-chip AGC with possibility of external control
nSingle supply voltage 3.3 V, range 2.97 V to 3.6 V
nBias voltage for PIN diode
nOn-chip current mirror of average photo current for RSSI monitoring
nIdentical ports available on both sides of die for easy bond layout and RF polarity
selection

3. Applications

nDigital fiber optic receiver modules in telecommunications transmission systems, in
high-speed data networks or in FTTx systems.

TZA3046

Fiber Channel/Gigabit Ethernet transimpedance amplifier

Rev. 01 — 19 May 2006 Product data sheet
CAUTION
This device is sensitive to ElectroStatic Discharge (ESD). Therefore care should be taken
during transport and handling.