19-1601; Rev 2; 11/05
622Mbps, Ultra-Low-Power, 3.3V
Transimpedance Preamplifier for SDH/SONET
The MAX3665 low-power transimpedance preamplifier
for 622Mbps SDH/SONET applications consumes only
70mW at VCC = 3.3V. Operating from a single +3.3V or
+5.0V supply, it converts a small photodiode current to a
measurable differential voltage. A DC cancellation circuit
provides a true differential output swing over a wide
range of input current levels, thus reducing pulse-width
distortion. The differential outputs are back-terminated
with 50Ω per side.
The overall transimpedance gain is nominally 8kΩ. For
input signal levels beyond approximately 50µAp-p, the
amplifier will limit the output swing to 250mV. The
MAX3665’s low 55nA input noise provides a typical
sensitivity of -33.2dBm in 1300nm, 622Mbps receivers.
The MAX3665 is designed to be used in conjunction
with the MAX3676 clock recovery and data retiming IC
with limiting amplifier. Together they form a complete
3.3V or 5.0V 622Mbps SDH/SONET receiver.
In die form, the MAX3665 is designed to fit on a header
with a PIN diode. It includes a filter connection that pro-
vides positive bias for the photodiode through a 1.5kΩ
resistor to VCC. The device is available in an 8-pin
♦ +3.3V or +5.0V Single-Supply Operation
♦ 55nARMS Input-Referred Noise
♦ 70mW Power Consumption at VCC = 3.3V
♦ 8kΩ Gain
♦ 450µA Peak Input Current
♦ 260ps (max) Deterministic Jitter
♦ Differential Output Drives 100Ω Load
♦ 470MHz Bandwidth
-40°C to +85°C
Note: Dice are designed to operate over a -40°C to +140°C
junction temperature (Tj) range, but are tested and guaranteed
at TA = +25°C.
________________________Applications Pin Configuration appears at end of data sheet.
PIN Photodiode Preamplifiers and Receivers
µMAX is a registered trademark of Maxim Integrated Products, Inc.
Regenerators for SDH/SONET
__________________________________________________Typical Application Circuit
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.