회사 블로그 TI DDC2256 Single-Chip 24-Bit 256-Channel Current-Input Analog-To-Digital Converter

Shenzhen Mingjiada Electronics Co., Ltd. supplies the TI DDC2256 single-chip 24-bit, 256-channel current-input analogue-to-digital converter.

The DC2256 is an integrated 24-bit, 256-channel current-input analogue-to-digital converter launched by TI, forming part of the DDC charge-to-digital conversion series. A single chip can simultaneously acquire 256 weak current signals, integrating the integration amplification and ADC conversion within the same chip, thereby eliminating the need for a large number of discrete transimpedance amplifier circuits. It is particularly well-suited for signal acquisition in high-density photodetector array applications and is commonly used in equipment such as CT (computed tomography) scanners, multi-channel photodiode arrays, radiation detection and spectroscopic analysis. Texas Instruments.

The DDC2256 device incorporates 256 independent, low-noise integration channels, each equipped with a dedicated integrator capable of fully capturing the sensor’s output charge without any charge loss, whilst supporting synchronous sampling. The integration time is flexibly configurable, ranging from 58.8 μs to 100 ms, with a maximum sampling rate of 17 kSPS per channel. This enables high-precision measurement of weak currents in the fA to μA range, catering to detection requirements across varying brightness levels and radiation intensities. Texas Instruments.

1. Key Specifications of the DDC2256
- Resolution: 24 bits
- Number of channels: 256 independent current input channels, synchronous integration acquisition
- Integration mode: Charge integration architecture, with built-in integration capacitance and a programmable full-scale charge range
- Sampling rate: Minimum integration time of 58.8 μs, up to 17 kSPS per channel; integration duration is configurable to balance noise and speed
- Linearity: Integration non-linearity ±0.025% FSR (typically ±1 ppm FSR)
- Noise performance: Minimum background noise as low as 0.2 fC rms (approximately 1,250 electrons), suitable for extremely weak charge detection applications
- Power supply architecture: analogue ±2.5 V and 1.8 V for the analogue core, 1.8 V for the digital core
- Per-channel power consumption: typically 1.7 mW
- Operating temperature: 0 °C to 70 °C
- Digital interface: LVDS high-speed serial output interface
- Package: 323-pin NFBGA, 14 mm × 16 mm

2. DDC2256 Product Features
1. Native current-input architecture directly acquires charge signals, eliminating the need for an external TIA (transimpedance amplifier) and reducing signal-chain noise and the number of components
2. All 256 channels feature synchronous integration and synchronous readout, ensuring high timing consistency between channels and eliminating timing deviations caused by time-division switching
3. Full-scale charge can be switched by configuring the integration capacitance, allowing users to adjust gain as required and flexibly optimise the noise floor and dynamic range
4. 24-bit high resolution and wide dynamic range, capable of simultaneously capturing faint charge signals with vast differences in amplitude
5. Built-in reference and integration control logic; the I-V conversion and ADC conversion are performed internally, simplifying the system architecture
6. LVDS differential serial interface enables high-speed, low-noise transmission; it is compatible with FPGA back-end reception and suppresses common-mode interference in the transmission link
7. Excellent channel consistency with controllable gain and offset deviations between channels, reducing the workload for back-end calibration
8. Supports cascading multiple chips to expand the channel array, enabling the construction of ultra-large-area detection systems

3. Core Advantages of the DDC2256
High integration is the most prominent advantage of the DDC2256A. A single chip accommodates 256 acquisition channels; compared to solutions using multiple low-channel-count ADCs, this significantly reduces PCB area, lowers BOM costs and facilitates the miniaturisation of the entire system. The synchronous parallel acquisition mechanism is ideally suited to imaging array detectors, ensuring that all pixels are exposed and integrated simultaneously, thereby preventing image distortion caused by scanning timing.

It offers outstanding adaptability to weak signals; the charge-integration architecture is highly suited to microcurrent signals in the picoampere and pico-coulomb ranges, allowing direct interfacing with photodiodes and X-ray detector arrays. The programmable full-scale charge design enables a single chip to support both low-noise, high-precision modes and high-charge-range modes, allowing a single hardware configuration to accommodate a variety of detection scenarios.

Power consumption is excellently controlled; overall power consumption remains manageable even when all 256 channels are active, making it suitable for equipment requiring prolonged continuous imaging. The differential LVDS output offers strong immunity to interference, ensuring better data stability in complex electromagnetic environments such as medical equipment and industrial radiation detection. Additionally, TI provides the DDC2256AEVM evaluation board, which supports rapid verification and algorithm debugging, thereby shortening the overall system development cycle.

4. Typical Applications of the DDC2256
- CT (Computed Tomography) detector arrays; X-ray detection and readout circuits for medical CT equipment (this device is a classic, dedicated ADC for CT imaging)
- Signal acquisition for photodiode arrays and silicon photomultiplier tube arrays
- Particle detection, ionisation chambers, and radiation detection array readout
- Spectral imaging and multi-channel low-light detection equipment
- Industrial non-destructive testing and surface array detectors for radiographic testing
- High-channel-density scientific instruments and instruments for measuring minute charges

[Supply Process]
Mingjiada Electronics supports sample requests, small-batch trial production and long-term mass production framework supply for the DDC2256. We also provide complementary supply of other models within the TI DDC series, whilst adhering to genuine product control procedures throughout the entire process:

1. Requirements Coordination and Technical Pre-assessment
Customers submit details regarding the DDC2256 model, package type, required quantity, lead time and application scenario via email, online enquiries or through their account manager. Technical engineers simultaneously verify whether the device specifications, power supply, interfaces and temperature range are compatible with the project requirements, and provide data sheets and evaluation reference materials. For high-reliability projects such as medical imaging, requirements regarding production batches and traceability documentation can be discussed concurrently.
 

2. Stock Verification and Formal Quotation
The supply chain team verifies stock levels at our Shenzhen and Hong Kong warehouses, as well as TI’s factory production schedule, and promptly provides feedback on stock availability, unit prices and lead times, distinguishing between sample prices and tiered volume pricing. We clarify whether original manufacturer Certificates of Conformity (COCs) and batch reports can be provided, and lock in delivery dates for long-lead-time orders.
 

3. Order Confirmation and Agreement Signing
Both parties confirm the quotation and delivery terms, and may sign a purchase contract and an NDA (Non-Disclosure Agreement); we support various payment methods, including T/T. For long-term mass production projects, we can negotiate a framework stockholding agreement to secure supply and lock in prices.
 

4. Incoming Goods Inspection and Warehouse Control
Upon arrival at the warehouse, components undergo incoming goods inspection: visual inspection, silkscreen verification, verification of moisture-proof and anti-static packaging, and entry of batch information into the traceability system. For BGA packages, particular attention is paid to the integrity of the solder balls to prevent the inclusion of refurbished, loose new or re-coded materials.
 

5. Anti-static and Moisture-proof Packaging for Dispatch
As the DDC2256 is a precision BGA component, it is packaged for dispatch in vacuum moisture-proof bags on anti-static trays, labelled with the model number, lot number, quantity and inspection label. Samples are prioritised for express delivery; domestic spot orders are dispatched within 48 hours, whilst cross-border orders can be arranged for delivery to a Hong Kong warehouse or via DDP door-to-door logistics.
 

6. Logistics Tracking and Incoming Goods Inspection Support
A tracking number is provided for end-to-end tracking following dispatch. Upon delivery, we support customers’ re-inspection of incoming goods; relevant original manufacturer’s quality documentation is supplied with the shipment. Should there be any queries regarding specifications or packaging, our technical and commercial teams will liaise promptly to resolve the matter. We can subsequently provide restocking services, recommendations for alternative models, and the supply of complementary DDC devices from the same series.