Overview
The AD9940BCPZ, produced by Analog Devices Inc., is a high-speed, correlated double sampler designed for high-speed digital imaging applications. It integrates a programmable timing driver using the Precision Timing core, which allows for precise control over high-speed clocks necessary for CCD imaging systems. The device features a 56 MHz CDS amplifier with 6 dB of fixed gain, an internal voltage reference supply, and output buffers for driving PCB traces and connecting directly to an image signal processor like the AD9941. The AD9940 operates from a single 2.7 V power supply and is available in 48-lead LQFP and 48-lead LFCSP packages.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Operating Temperature Range | -25 | +85 | °C | |
| Storage Temperature Range | -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 (excluding H/RG drive current) | 105 | mW @ 2.7V | ||
| Power Dissipation (excluding H/RG drive current) | 115 | mW @ 3.0V | ||
| 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
- 56 MSPS correlated double sampler (CDS) with 6 dB fixed gain
- Integrated programmable timing driver using the Precision Timing core with 0.37 ns resolution at 56 MSPS
- Single-supply operation (2.7 V min)
- Internal voltage reference supply
- Output buffers providing drive strength for PCB traces and direct connection to an image signal processor like the AD9941
- Fully differential outputs for good signal integrity
- Includes H-drivers for H1 to H4, HL, and RG clocks, supporting up to 3.6 V H-drive voltage
- DC restore circuit to reduce large dc offset of the CCD output signal
- Low power CMOS: 105 mW at 2.7 V (115 mW at 3.0 V)
- Available in 48-lead LQFP and 48-lead LFCSP packages
Applications
- Professional HDTV camcorders
- Professional/high-end digital cameras
- Broadcast cameras
- Industrial high-speed cameras
- High-speed data-acquisition systems
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.
- How much power does the AD9940 typically dissipate?
The AD9940 typically dissipates 105 mW at 2.7 V and 115 mW at 3.0 V, excluding the H/RG drive current.
- What types of packages are available for the AD9940?
The AD9940 is available in 48-lead LQFP and 48-lead LFCSP packages.
- What is the resolution of the Precision Timing core in the AD9940?
The Precision Timing core in the AD9940 has a resolution of 0.37 ns at 56 MSPS.
- How are the CCD and AFE timing parameters programmed into the AD9940?
The CCD and AFE timing parameters are programmed into the AD9940 from the system microprocessor through a 3-wire serial interface.
- What is the purpose of the DC restore circuit in the AD9940?
The DC restore circuit is used to reduce the large dc offset of the CCD output signal, restoring the dc level to approximately 1.5 V.
- 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 are some common applications of the AD9940?
The AD9940 is commonly used in professional HDTV camcorders, high-end digital cameras, broadcast cameras, industrial high-speed cameras, and high-speed data-acquisition systems.
