Overview
The AD9845B, produced by Analog Devices Inc., is a complete 12-bit, 30 MSPS (Mega Samples Per Second) CCD (Charge-Coupled Device) signal processor. This component is designed to sample and condition the outputs of both interlaced and progressive scan area CCD arrays. It features a single-channel architecture and includes a comprehensive signal chain consisting of an input clamp, a correlated double sampler (CDS), a Pixel Gain Amplifier (PxGA), a digitally controlled variable gain amplifier (VGA), a black level clamp, and a 12-bit A/D converter. The AD9845B is an improved version of the AD9845A, offering enhanced performance and additional features such as programmable gain adjustment, black level adjustment, and power-down modes through a 3-wire serial digital interface.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Temperature Range (Operating) | -20 | 85 | °C | |
| Temperature Range (Storage) | -65 | 150 | °C | |
| Power Supply Voltage | 2.7 | 3.0 | 3.6 | V |
| Power Consumption (Normal Operation) | 153 | mW | ||
| Maximum Clock Rate | 30 | MHz | ||
| PxGA Gain Range | -2.5 dB | 9.5 dB | ||
| VGA Gain Range | 0 dB | 36 dB | ||
| Input Range before Saturation | 1.0 V p-p | |||
| Package Type | 48-Lead LQFP |
Key Features
- Single-channel architecture designed to sample and condition CCD array outputs.
- Comprehensive signal chain including input clamp, CDS, PxGA, VGA, black level clamp, and 12-bit A/D converter.
- Programmable features via a 3-wire serial digital interface: gain adjustment, black level adjustment, input configuration, and power-down modes.
- Single 3 V power supply operation with low power consumption (typically 153 mW).
- Space-saving 48-lead LQFP package.
- Additional input modes for processing analog video signals.
Applications
- High-performance digital still cameras.
- Industrial and scientific imaging applications.
Q & A
- What is the primary function of the AD9845B?
The AD9845B is a complete 12-bit, 30 MSPS CCD signal processor designed to sample and condition the outputs of interlaced and progressive scan area CCD arrays.
- What are the key components of the AD9845B's signal chain?
The signal chain includes an input clamp, a correlated double sampler (CDS), a Pixel Gain Amplifier (PxGA), a digitally controlled variable gain amplifier (VGA), a black level clamp, and a 12-bit A/D converter.
- How is the AD9845B programmed?
The internal registers are programmed through a 3-wire serial digital interface.
- What are the programmable features of the AD9845B?
Programmable features include gain adjustment, black level adjustment, input configuration, and power-down modes.
- What is the power supply requirement for the AD9845B?
The AD9845B operates from a single 3 V power supply.
- What is the typical power consumption of the AD9845B?
The typical power consumption is 153 mW.
- What is the maximum clock rate of the AD9845B?
The maximum clock rate is 30 MHz.
- What are the gain ranges for the PxGA and VGA?
The PxGA gain range is from -2.5 dB to 9.5 dB, and the VGA gain range is from 0 dB to 36 dB.
- In what package is the AD9845B available?
The AD9845B is packaged in a 48-lead LQFP.
- What are some common applications of the AD9845B?
Common applications include high-performance digital still cameras and industrial/scientific imaging.
