Overview
The AD9940BCPZRL, produced by Analog Devices Inc., is a high-speed, correlated double sampler designed for high-speed digital imaging applications. This component integrates a programmable timing driver using the Precision Timing core, making it ideal for CCD imaging systems. It features a 56 MHz CDS amplifier with 6 dB of fixed gain, an internal voltage reference supply, and precise timing control for all high-speed clocks necessary in CCD imaging. The AD9940 operates from a single 2.7 V power supply and is available in 48-lead LFCSP packages.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Temperature Range (Operating) | -25 | 85 | °C | |
| Temperature Range (Storage) | -65 | 150 | °C | |
| Maximum Clock Rate | 56 | MHz | ||
| Power Supply Voltage (AVDD, TCVDD, OVDD, DVDD, HVDD, RGVDD) | 2.7 | 3.0 | 3.6 | V |
| Power Dissipation (AFE supplies = 2.7 V, no H or RG drivers) | 105 | mW | ||
| Power Dissipation (AFE supplies = 3.0 V, no H or RG drivers) | 115 | mW | ||
| High Level Input Voltage (VIH) | 2.1 | V | ||
| Low Level Input Voltage (VIL) | 0.6 | V | ||
| High Level Output Voltage (VOH), IOH = 2 mA | 2.2 | V | ||
| Low Level Output Voltage (VOL), IOL = 2 mA | 0.5 | V |
Key Features
- High-speed correlated double sampler with integrated programmable timing driver using the Precision Timing core.
- 56 MHz CDS amplifier with 6 dB of fixed gain.
- Internal voltage reference supply.
- Precise timing control for all high-speed clocks necessary in CCD imaging systems.
- Output buffers providing drive strength for PCB traces and direct connection to an image signal processor like the AD9941.
- Operates from a single 2.7 V power supply.
- Available in 48-lead LFCSP and LQFP packages.
- H-drivers for H1 to H4, HL, and RG clocks, supporting up to 3.6 V.
- DC restore circuit to reduce large dc offset of the CCD output signal.
Applications
The AD9940 is primarily used in high-speed digital imaging applications, including:
- CCD imaging systems.
- High-speed cameras.
- Industrial high-speed imaging.
- Applications requiring separate placement of CDS and VGA/ADC circuits on different PCBs.
Q & A
- What is the primary function of the AD9940?
The AD9940 is a high-speed, correlated double sampler designed for high-speed digital imaging applications.
- What is the maximum clock rate of the AD9940?
The maximum clock rate of the AD9940 is 56 MHz.
- What is the power supply voltage range for the AD9940?
The power supply voltage range for the AD9940 is 2.7 V to 3.6 V.
- What type of packages is the AD9940 available in?
The AD9940 is available in 48-lead LFCSP and LQFP packages.
- What is the purpose of the Precision Timing core in the AD9940?
The Precision Timing core allows adjustment of high-speed clocks with a resolution of 0.37 ns.
- How does the AD9940 handle dc offset in CCD output signals?
The AD9940 uses a dc restore circuit to reduce the large dc offset of the CCD output signal.
- Can the AD9940 be used with other image signal processors?
Yes, the AD9940 is designed to provide good signal integrity when interfaced with differential input image signal processors like the AD9941.
- What is the typical power dissipation of the AD9940 without H or RG drivers?
The typical power dissipation of the AD9940 without H or RG drivers is 105 mW at 2.7 V and 115 mW at 3.0 V.
- How are the timing parameters programmed into the AD9940?
The timing parameters are programmed into the AD9940 from the system microprocessor through a 3-wire serial interface.
- What is the operating temperature range of the AD9940?
The operating temperature range of the AD9940 is -25°C to +85°C.
