FEATURES
· 12-Bit, 21-MSPS, Analog-to-Digital
Converter
· Low Power: 70 mW Minimum
Power-Down Mode: 4 mW
· Low Input-Referred Noise: 75-dB
SNR Typical at 0-dB Gain
· Novel Optical-Black (OB) Calibration
· Low-Aperture Delay
· Single 3-V Supply Operation
· DNL: <±0.5 LSB and
INL: <±1.5 LSB Typical at 0-dB Gain
· Programmable-Gain Range: 0 dB to 36 dB,
Gain Resolution of 0.05 dB/Step
· 48-Pin TQFP Package

APPLICATIONS
· Digital Still Camera
· Digital Video Camera

DESCRIPTION
The VSP1221 is a highly-integrated mixed-signal IC
used for signal conditioning and analog-to-digital
conversion at the output of a CCD array. The IC has
correlated double sampler (CDS) and an analog
programmable-gain amplifier (PGA) stage followed by
analog-to-digital converter (ADC) and a digital
PGA stage. The CDS is used to sample the CCD
signal and is followed by the analog PGA stage. The
ADC is a12-bit, 21-MSPS pipelined ADC. The digital
PGA provides further amplification.
Additionally, there is an offset calibration loop for
optical-black correction. The optical-black reference
level is user-programmable. The chip also has two
bit digital-to-analog converters (DAC) for external
analog settings.
The chip has a serial port for configuring internal
control registers.
The VSP1221 is available in a 48-pin TQFP package
and operates from a single 3-V power supply.