Interface & Connectivity



The HXT44100 is a single channel, low power, Linear PAM4 Direct Modulated Laser (DML) driver for LR optical applications that supports signaling rates up to 28GBaud or 56Gbps PAM4. In conjunction with an individual DFB laser diode, the device handles the complete digital-to-optical conversion, including CML input with equalization, laser driver, drive control, and supervision. The HXT44100 also integrates a number of functions required for Automatic Power Control (APC), as well as internal and module temperature measurements and reporting. Using the included RSSI input, the module receive optical power can also be measured and reported. Designed for direct DC-coupled die in TOSA applications with a small number of additional components for cost-effective and compact assemblies. Available in die form.


  • 300mW per channel PDISS if configured for:
    • IMOD = 60mAPP
    • IBIAS = 60mA
  • Supports up to: IMOD = 60mAPP & IBIAS = 60mA with VCC = 2.5V
  • Integrated 12-bit ADC with 6 channel analog multiplexor front-end
  • Programmable 8-bit laser modulation and bias current control
  • Integrated bias monitor, transmit and receive power monitor capability
  • Automatic power control (APC)
  • Programmable input LOS and squelch function with disable, transmit disable, and transmit fault indication
  • Programmable input CTLE equalization
  • Integrated temperature sensor and input for external module temperature sensor
  • Interrupts with user selectable mask control
  • Input polarity inversion
  • Laser disable for IMOD and IBIAS
  • Integrated OTP for calibration
  • 2-wire interface control



Title Type Date
Datasheet - Short-form

Design & Development