MCM20027 Datasheet, PDF (19/73 Pages) Motorola, Inc – Color SXGA Digital Image Sensor 1280 x 1024 pixel progressive scan solid state image sensor

MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
ImageMOS
7.5 Global Digital Offset Voltage Adjust (DOVA)
A programmable global offset adjustment is available
on the MCM20027. A user defined offset value is loaded
via a 6-bit signed magnitude programming code via the
Global DOVA Register, (Table 28), on page 47.
Offset correction allows fine-tuning of the signal to re-
move any additional residual error which may have ac-
cumulated in the analog signal path. This function is
performed directly before analog to digital conversion
and introduces a fixed gain of 2.0X. This feature is use-
ful in applications that need to insert a desired offset to
adjust for a known system noise floor relative to AVSS
and offsets of amplifiers in the analog chain.
7.6 Analog to Digital Converter (ADC)
The ADC is a fully differential, low power circuit. A pipe-
lined, Redundant Signed Digit (RSD) algorithmic tech-
nique is used to yield an ADC with superior
characteristics for imaging applications.
Integral Noise Linearity (INL) and Differential Noise Lin-
earity (DNL) performance is specified at +1.0 and +0.5,
respectively, with no missing codes. The input voltage
resolution is 2.44 mV with a full-scale 2.5 V_pp input (2.5
V_pp/2¹⁰). The input dynamic range of the ADC is pro-
grammed via a Programmable Voltage Reference Gen-
erator. The positive reference voltage (VREFP) and
negative reference voltages (VREFM) can be pro-
grammed from 2.5V to 1.25V and 0V to 1.25V respec-
tively in steps of 5mV via the Reference Voltage
Registers (Table 17 and Table 18). This feature is used
independently or in conjunction with the DPGAs to max-
imize the system dynamic range based on incident illu-
mination. The default input range for the ADC is 1.9V for
VREFP and 0.6V for VREFM hence allowing a 10 bit
digitization of a 1.3V peak to peak signal.
Revision 8.0 - 28 November 2001 : MCM20027
MOTOROLA
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