VSP2254GSJR

Overview

The VSP2254GSJR is a dual-channel mixed-signal integrated circuit designed for CCD signal processing, manufactured by Texas Instruments. It integrates two independent channels of Correlated Double Sampling (CDS) and a 14-bit Analog-to-Digital Converter (ADC). The device operates on a single supply voltage ranging from 2.7 V to 3.6 V. Key electrical specifications include a maximum conversion rate of 36 MHz, a typical power dissipation of 210 mW at 3 V, and a Signal-to-Noise Ratio (SNR) of 75 dB. It features black level clamping, input signal clamping, and offset correction capabilities.

Feature Summary

• Integrates dual-channel Correlated Double Sampling (CDS) with 14-bit ADCs for high-resolution CCD signal digitization.
• Includes an auto-zero black level clamp loop using optical black pixels to establish accurate reference levels.
• Supports portable operation through low-voltage compatibility and dedicated standby mode for power reduction.
• Provides input clamping and offset correction to maintain signal integrity during CCD data acquisition.

Applications

• Digital Video Camera (DVC)
• Digital Still Camera (DSC)
• Front-end processing for dual-channel CCD sensors

Procurement Notes

Verify the specific suffix 'GSJR' corresponds to the tape and reel transport media and the -25°C to 85°C operating temperature range as defined in the ordering information. Confirm that the BGA 96 package code matches the required PCB footprint. Ensure design compliance with ESD handling precautions due to the sensitivity of precision analog circuits. Cross-reference the latest datasheet revision for any updates to absolute maximum ratings or decoupling recommendations.

Selection Notes

Select this component when designing systems requiring simultaneous dual-channel CCD signal processing with high resolution. It is suitable for applications demanding low power consumption in portable devices. Designers must account for the 8-clock data latency and ensure proper timing alignment between SHP, SHD, and ADCCK signals. Adequate decoupling of analog and digital supplies is critical to maintain the specified SNR and linearity performance.

Part Context

The VSP2254 belongs to Texas Instruments' family of mixed-signal processors optimized for image sensor interfaces. It addresses the need for compact, low-power solutions in consumer imaging electronics. The device replaces discrete CDS and ADC implementations, reducing board space and complexity. Its architecture supports direct interfacing with CCD outputs via AC coupling, simplifying front-end circuit design for camera manufacturers.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.

FAQ

How does the VSP2254 handle black level calibration?

The device uses an auto-zero loop that identifies the black level from CCD optical black pixels. A 10-bit current DAC adjusts the CDS offset until the ADC output code converges to the black level reference during the active CLPOB period.

What is the data latency of the VSP2254?

The VSP2254 has a fixed data latency of 8 clocks. Digital output data appears at the rising edge of ADCCK with a delay of seven clock cycles relative to the input sampling event.

Can the VSP2254 be powered down to save energy?

Yes, forcing the STB input high places the device in standby mode. In this state, all function blocks are disabled, digital outputs go to zero, and power consumption drops to approximately 14 mW.