Analog Devices Inc. AD9945KCPZRL7

Overview

AD9945KCPZRL7 from Analog Devices is a complete 12-bit, 40 MSPS CCD signal processor IC featuring a correlated double sampler (CDS), 10-bit VGA (6–40 dB gain), optical black clamp, and integrated 12-bit ADC - all operating from a single 3 V supply in a 32-lead LFCSP package for digital still cameras and camcorders.

For engineers reviewing the AD9945KCPZRL7 datasheet, AD9945KCPZRL7 pinout, AD9945KCPZRL7 application, or AD9945KCPZRL7 equivalent, key selection criteria include guaranteed no-missing-codes ADC performance, 0.1% peak nonlinearity across full signal chain, 1.2 LSB_rms total output noise at 6 dB gain, and programmable CDS timing via SHP/SHD clocks.

Technical Context

The AD9945KCPZRL7 implements a single-channel analog front end optimized for interlaced and progressive-scan CCD arrays, with internal timing generation synchronized to DATACLK, SHP, and SHD inputs. Its CDS stage samples on rising edges of SHP (reference level) and SHD (data level), with 3 ns internal aperture delay and precise 6.25 ns minimum pulse width requirements.

Signal conditioning includes dc restoration via external 0.1 µF coupling capacitor, programmable 8-bit optical black clamp level (0–255 LSB), and 10-bit VGA gain control (1024 steps) using the equation Gain(dB) = 0.035 × Code + 5.3. The 12-bit ADC uses straight binary coding, 2.0 V full-scale input range, and guarantees no missing codes over –20°C to +85°C.

Key Specifications

Pinout & Package

AD9945KCPZRL7 is housed in a 32-lead Lead Frame Chip Scale Package (LFCSP_WQ), 5 mm × 5 mm body, with exposed thermal pad requiring soldering to PCB ground plane per JEDEC MO-220-WHHD standard (CP-32-7).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar CCD signal processor applications.

Compared with AD9945KCPZRL7, the TDC1308IPWPR offers lower integration and resolution for cost-driven line-scan use cases, while the LM98714BCMTX/NOPB provides higher bit depth and dual-supply flexibility at the expense of power and board space - making AD9945KCPZRL7 optimal for compact, single-supply 12-bit area-array CCD systems.

Availability

AD9945KCPZRL7 is available at Aetrix Electronics and suitable for digital still cameras, CCTV surveillance systems, and portable CCD imaging devices requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for AD9945KCPZRL7 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

Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and consumer markets with precision technology.

The AD9945KCPZRL7 belongs to Analog Devices' CCD signal processor product line, engineered specifically for high-fidelity, low-noise analog front ends in portable and embedded imaging systems using interlaced or progressive CCD sensors.

FAQ

What is the required start-up sequence for the AD9945KCPZRL7?

The AD9945KCPZRL7 requires a mandatory start-up write of 0x838 to Register 0xD within 1 ms after power-on to initialize internal calibration and timing circuits. This value must be loaded via the 3-wire serial interface (SCK, SDATA, SL) before normal operation begins. Failure to perform this write results in undefined behavior and potential loss of CDS synchronization. The AD9945KCPZRL7 includes internal power-on reset circuitry that completes in ~1 ms, during which serial writes are ignored until reset finishes.

Does the AD9945KCPZRL7 support both interlaced and progressive scan CCDs?

Yes, the AD9945KCPZRL7 supports both interlaced and progressive scan CCD arrays through its configurable CDS timing architecture. The SHP and SHD clocks operate independently and can be aligned to match field-based (interlaced) or frame-based (progressive) sampling windows. Internal timing registers allow polarity inversion and programmable delays to accommodate varying CCD timing specifications. The AD9945KCPZRL7's 40 MSPS sampling rate and pipeline latency of 10 cycles are validated for both scan types in Analog Devices' system applications diagram (Figure 10).

How is the optical black clamp function implemented in the AD9945KCPZRL7?

The AD9945KCPZRL7 implements optical black clamping using an internal feedback loop that compares the ADC output during CLPOB-active periods (optical black pixels) against a user-programmed 8-bit clamp level (0–255 LSB). The resulting error is filtered and applied via an 8-bit DAC to the ADC input path. CLPOB must be asserted for ≥20 pixels to minimize noise; shorter pulses degrade low-frequency tracking. The AD9945KCPZRL7 also allows disabling the clamp loop (via Bit D3 in Operation Register) while retaining programmable offset adjustment capability.

What are the decoupling requirements for the AD9945KCPZRL7's analog and digital supplies?

The AD9945KCPZRL7 requires separate 0.1 µF ceramic decoupling capacitors placed within 2 mm of each supply pin: AVDD/AVSS, DVDD/DVSS, and DRVDD/DRVSS. REFT and REFB each need individual 0.1 µF capacitors to AVSS. A continuous analog ground plane is mandatory, with DRVSS connected directly to it. Digital supplies should share the same ground plane but be routed to avoid coupling noise into analog sections. The exposed thermal pad must be soldered to this ground plane to ensure thermal stability and noise immunity.

Can the AD9945KCPZRL7 operate with a 2.85 V supply instead of 3.0 V?

Yes, the AD9945KCPZRL7 is fully specified at 2.85 V for DRVDD and DVDD (per Digital Specifications table), and operates reliably across 2.85 V to 3.6 V for all supplies (AVDD, DVDD, DRVDD). At 2.85 V, typical power consumption decreases slightly, and timing parameters remain within spec - including 40 MSPS sampling and 10 MHz SCK limit. However, full 12-bit performance (DNL, SNR) is guaranteed only at 3.0 V per System Specifications; operation at 2.85 V is validated for functional compatibility but may reduce noise margin by ~0.2 LSB_rms.