The MP5490 is a fully integrated power management integrated circuit (PMIC) specifically designed for transmitter optical sub-assemblies (TOSA) in optical modules, developed by Monolithic Power Systems (MPS). This device integrates multiple precision analog and digital functions to support high-performance optical transmission applications.

　　Key Features:

　　·Four-channel high-precision current source (IDAC): Each channel delivers up to 250 mA with 10-bit DAC resolution, enabling fine current control with a step size of 0.25 mA per LSB.

　　·Four-channel electro-absorption modulated laser (EML) negative bias voltage generation: Output voltage is programmable from –0.1 V to –2.5 V (default range) or –5.0 V (optional range), with each channel capable of driving up to 60 mA load current.

　　·Four-channel monitoring photodiode (MPD) current measurement: Supports input current range from 0 mA to 5 mA for real-time optical output monitoring.

　　·Six-channel general-purpose input/output (GPIO): Configurable as either analog inputs for ADC measurement or digital outputs for system control.

　　·High-accuracy 12-bit analog-to-digital converter (ADC): Provides external voltage measurement capability with an input range of 0 V to 2.5 V.

　　· I²C serial interface: Enables configuration, monitoring, and control via standard I²C protocol; supports hardware reset and fault interrupt signaling for enhanced system reliability.

　　·Package: Compact WLCSP-36 package measuring 3.0 mm × 4.25 mm, suitable for space-constrained optical module designs.

　　2. Functional Module Descriptions

　　2.1 Current Source Module

　　Specifications:

　　Number of channels: 4 (ID1–ID4)

　　Output current range: 0 mA to 250 mA per channel

　　Resolution: 10-bit DAC (step size: 0.25 mA/LSB)

　　Control method: Programmable via I²C interface or non-volatile MOTP memory

　　Independent enable control via dedicated LD_ON pin for each channel

　　Protection features: Channel-level short-circuit protection (SCP), configurable for auto-recovery or latched shutdown mode

　　2.2 EML Bias Voltage Module

　　Specifications:

　　Number of channels: 4 (VB1–VB4)

　　Output voltage range: –0.1 V to –2.5 V (default), extendable to –5.0 V (optional)

　　Load current capability: Up to 60 mA per channel

　　Resolution: 10-bit DAC (voltage step size: 2.5 mV/LSB)

　　Control method: Configurable via I²C interface or stored in MOTP memory

　　Protection mechanism: Overcurrent protection threshold set at 150 mA per channel

　　2.3 Monitoring and ADC Functions

　　Functional Overview:

　　Four-channel MPD current sensing (TX1–TX4): Measures monitor photodiode currents within the 0 mA to 5 mA range for optical feedback control.

　　Six-channel universal ADC: Incorporates a 12-bit high-resolution ADC with an input voltage range of 0 V to 2.5 V.

　　GPIO functionality: The six GPIO pins can be individually configured as ADC inputs or general-purpose digital outputs.

　　On-chip temperature monitoring: Integrated temperature sensor provides thermal data with a sensitivity of 0.074°C per LSB, supporting accurate thermal compensation and system diagnostics.

　　Technical Specifications

　　Input Voltage Range (VIN1)：2.7 to 5.5V

　　Input Voltage Range (VIN2)：1.2 to VIN1V

　　Negative Input Voltage (VIN3)：-5 to -2V

　　Operating Temperature：-40 to +125°C

　　Package：WLCSP-36 (3×4.25mm)

　　Applications

　　QSFP/QSFP-DD optical modules

　　400G/800G coherent optical transceivers

　　High-speed data center interconnects

　　5G fronthaul optical equipment

For more details about MPS products, please consult CORE customer service.