Texas Instruments DDC316CZXGR

Overview

DDC316CZXGR from Texas Instruments is a 16-bit, 16-channel current-input analog-to-digital converter with dual-switched integrator front-end, programmable full-scale range (3pC to 12pC), integration time down to 10µs, and serial/parallel data output modes. It directly digitizes low-level photodiode currents in medical CT scanner detector acquisition systems.

For engineers reviewing the DDC316CZXGR datasheet, DDC316CZXGR pinout, DDC316CZXGR application, or DDC316CZXGR equivalent, key selection criteria include its 16-channel current-input architecture, ±2 pA input bias current, BGA-64 package, 0°C to +70°C operating temperature, and compatibility with photodiode sensor arrays requiring sub-picoampere sensitivity and high channel density.

Technical Context

The DDC316CZXGR implements a continuous-time dual-switched integrator per channel: while one side (A or B) integrates input current, the other is digitized by the on-chip 16-bit ADC. Integration time is controlled externally via the CONV pin and CLK, with HI_SPEED bit enabling 10µs minimum integration.

It supports two output configurations: TDM mode (all 16 channels multiplexed on DOUT1) and parallel mode (four 4-channel groups on DOUT1–DOUT4). Reference voltage is configurable for internal (VREF) or external (VREF_IN) buffering, and resolution is programmable from 12 to 16 bits via configuration register RES[1:0].

Key Specifications

Pinout & Package

BGA-64 package (GXG/ZXG variant), 9 mm × 9 mm, 0.8 mm pitch, bottom-side thermal pad. Designed for high-density medical imaging PCB layouts with strict analog ground separation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar current-input ADC applications.

Compared with TLC4541IDW and ADAS1000-3BSTZ, the DDC316CZXGR uniquely integrates dual-switched current-to-voltage conversion and 16-channel digitization in a single BGA-64 package, eliminating external analog front-end components required by voltage-input alternatives and offering higher channel density than medical-specific ICs.

Availability

DDC316CZXGR is available at Aetrix Electronics and suitable for CT scanner detector acquisition systems, medical X-ray imaging subsystems, and industrial non-destructive testing arrays requiring stable component supply, long-lifecycle support, and traceable sourcing for Class II medical device manufacturing.

Supply support for DDC316CZXGR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of heritage in precision data converters and medical-grade signal chain solutions.

The DDC316CZXGR belongs to TI's high-precision current-input ADC product line, designed specifically for photon-counting and low-current sensor interfaces in diagnostic imaging, radiation detection, and scientific instrumentation.

FAQ

What is the minimum integration time supported by the DDC316CZXGR?

The DDC316CZXGR supports a minimum integration time of 10µs when the HI_SPEED bit is set to 0 and the master clock (CLK) is 40MHz. This timing is validated in the electrical characteristics table under HI_SPEED = 0 condition and enables high-speed photon counting in pulsed X-ray systems. The DDC316CZXGR achieves this via internal clock division and optimized integrator switching, maintaining ±2 pA input bias current even at shortest integration windows.

How does the DDC316CZXGR handle photodiode sensor capacitance variations?

The DDC316CZXGR compensates for sensor capacitance (CSENSOR) up to 100pF through three selectable integration capacitors (0.75pF, 1.5pF, 3pF) controlled by RANGE[1:0] bits. Its noise performance degrades predictably with CSENSOR-e.g., 3.5 LSB rms at 10pF rising to 9.4 LSB rms at 100pF in Range 1-allowing system designers to select optimal range and integration time. The DDC316CZXGR's dual-switched architecture inherently rejects common-mode capacitance effects across all 16 channels.

Can the DDC316CZXGR operate with an external voltage reference?

Yes, the DDC316CZXGR supports external voltage reference operation via the VREF_IN pin (pin 4B) when the BUFDIS bit is set to 1. In this mode, the internal reference buffer is disabled, allowing connection of precision external references such as REF5040 (4.096V) or ADR4540. This configuration improves long-term stability and reduces temperature drift to ±10 µV/°C DC bias voltage drift, critical for calibrated medical imaging systems. The DDC316CZXGR maintains full 16-bit linearity under external reference conditions.

What is the purpose of the QGND pin on the DDC316CZXGR?

The QGND pin (pin 5H) is a dedicated quiet analog ground terminal isolated from noisy digital ground paths and standard AGND pins. It provides a low-impedance return path for the internal reference buffer and sensitive integrator circuitry, minimizing ground bounce and coupling from digital switching noise. Layout best practices require connecting QGND directly to the analog ground plane with short, wide traces-separate from DGND-and using it as the reference point for VREF and AVDD decoupling capacitors. This design feature is integral to achieving the DDC316CZXGR's specified 8 LSB integral linearity error.

How does the DDC316CZXGR manage channel-to-channel matching?

The DDC316CZXGR guarantees ±0.2% full-scale range (FSR) matching between channels and ±10 ppm/°C range drift match, verified across production lots. This matching is achieved through laser-trimmed on-chip integration capacitors and matched transistor pairs in the dual-switched integrator front-end. The DDC316CZXGR's architecture ensures that gain and offset errors track consistently across temperature and supply voltage, enabling accurate multi-channel differential measurements in CT detector arrays without per-channel calibration. Match specifications apply to both sides (A/B) of each channel.