The LM98725 is a fully integrated, high performance 16-Bit, 81 MSPS signal processing
solution for digital color copiers, scanners, and other image processing applications. The LM98725
achieves high-speed signal throughput with an innovative architecture utilizing Correlated Double
Sampling (CDS), typically employed with CCD arrays, or Sample and Hold (S/H) inputs (for higher
speed CCD or CMOS image sensors). The signal paths utilize 8 bit Programmable Gain Amplifiers
(PGA), a ±9-Bit offset correction DAC, and independently controlled Digital Black Level correction
loops for each input. The independently programmed PGA and offset DAC allow unique values of gain
and offset for each of the three analog inputs. The signals are then routed to a 81 MHz high
performance analog-to-digital converter (ADC). The fully differential processing channel shows
exceptional noise immunity with a very low noise floor of –74 dB. The 16-bit ADC has excellent
dynamic performance making the LM98725 transparent in the image reproduction chain.
A very flexible integrated Spread Spectrum Clock Generation (SSCG) modulator is included
to assist with EM compliance and reduce system costs.
The LM98725 is a fully integrated, high performance 16-Bit, 81 MSPS signal processing
solution for digital color copiers, scanners, and other image processing applications. The LM98725
achieves high-speed signal throughput with an innovative architecture utilizing Correlated Double
Sampling (CDS), typically employed with CCD arrays, or Sample and Hold (S/H) inputs (for higher
speed CCD or CMOS image sensors). The signal paths utilize 8 bit Programmable Gain Amplifiers
(PGA), a ±9-Bit offset correction DAC, and independently controlled Digital Black Level correction
loops for each input. The independently programmed PGA and offset DAC allow unique values of gain
and offset for each of the three analog inputs. The signals are then routed to a 81 MHz high
performance analog-to-digital converter (ADC). The fully differential processing channel shows
exceptional noise immunity with a very low noise floor of –74 dB. The 16-bit ADC has excellent
dynamic performance making the LM98725 transparent in the image reproduction chain.
A very flexible integrated Spread Spectrum Clock Generation (SSCG) modulator is included
to assist with EM compliance and reduce system costs.