This document is a datasheet for the Sipex SP8126B, a high-speed differential amplifier designed for Automatic Power Control (APC) systems, particularly in optical pickup heads. Here's a summary of the key information:

Core Function: The SP8126B converts photodiode current to a differential voltage, providing a signal used to maintain consistent laser power in optical drives (CD, DVD, Blu-ray).

Key Features & Specifications:

️· High Speed: Designed for fast response times crucial for tracking data on optical media.
️· Differential Output: Provides a more noise-immune signal.
️· Adjustable Gain: Gain can be set via external resistors (R_GAIN) to optimize performance for different applications and laser power levels. Target gain settings with corresponding R_GAIN values are provided in a table.
️· Low Power Consumption: Suitable for portable devices.
️· Compact Size: Available in a small 8-lead Chip-on-Board (COB) package (3.0mm x 3.5mm).
️· Operating Temperature Range: -20°C to +85°C
️· Supply Voltage: Not explicitly stated, but implied to be around 5V based on example configurations.
️· Capacitive Load Handling: Designed to drive up to 50pF of capacitive load.

Key Design Considerations (from the datasheet):

️· Layout: Critical to minimize parasitic inductance and capacitance, especially around the gain-setting resistors and output traces. Specific routing recommendations are provided.
️· Decoupling: Good supply decoupling is essential for high-frequency performance.
️· Gain Setting: Carefully selecting the R_GAIN resistor is crucial for achieving the desired performance.

️· PCB Material: FR4 material is recommended.

Ordering Information:

️· SP8126CB-3: The part number for the standard version of the chip.

Target Applications:

️· Optical disc drives (CD, DVD, Blu-ray)
️· Automatic Power Control (APC) systems.



In essence, this datasheet provides the necessary technical information for engineers to integrate the SP8126B into their optical drive designs, focusing on its performance characteristics and layout requirements.