1 Features

1• 3.3 V Single Supply Operation

• CDS or S/H Processing

• 35 MHz Channel Rate

• Enhanced ESD Protection on Timing, Control and

LVDS Pins

• Low Power CMOS Design

• 12 Terminal to 16 Terminal (Selectable) LVDS

Serialized Data Output

• 4-Wire Serial Interface

• 2 Channel Symmetrical Architecture

• Independent Gain and Offset Correction for Each

Channel

• Digital Black Level Calibration for Each Channel

• Digital White Level Calibration for Each Channel

• Programmable Input Clamp

• Key Specifications

– Maximum Input Level:

– 1.2 Vp-p (CDS Gain = 1.0)

– 0.58 Vp-p (CDS Gain = 2.1)

– Input Sample Rate:

– 5 to 35 MSPS - 6ch mode

– 10 to 35 MSPS - 3ch mode

– PGA Gain Range: 1x to 10x (0 to 20 dB)

– CDS/SH Gain Settings: 1x or 2.1x

– Total Channel Gain: 1x to 21x (0 to 26 dB)

– PGA Gain Resolution: 8 bits - Analog

– ADC Resolution: 10 bits

– ADC Sampling Rate: 10 to 70 MSPS

– SNR: 68.5 dB (Gain = 1x)

– Offset DAC Range:

– ±111 mV or ±59.5 mV - FDAC

– ±281 mV - CDAC

– Offset DAC Resolution:

– ±10 bits - FDAC

– ±4 bits - CDAC

– Supply Voltage: 3.0 V to 3.6 V

– Power Dissipation: 1.02 W (typical)

2 Applications

• High Performance Digital Color Copiers

• Scanners

• Other Image Processing Applications

3 Description

The LM98620 is a fully integrated, 10-Bit, 70 MSPS

signal processing solution for high performance digital color copiers, scanners, and other image processing

applications. High-speed signal throughput is

achieved with an innovative six channel architecture

utilizing Correlated Double Sampling (CDS), or

Sample and Hold (SH) type sampling. Gain settings of 1x or 2x are available in the CDS/SH input stage.

Each channel has a dedicated 1x to 10x (8 bit) PGA

that allows accurate gain adjustment. The Digital

White Level auto calibration loop can automatically

set the PGA value to achieve a selected white target level. Each channel also has a ±4 bit coarse and ±10-

bit fine analog offset correction DAC that allows offset

correction before the sample-and-hold amplifier.

These correction values can be controlled by an automated Digital Black Level correction loop. The

PGA and offset DACs for each channel are

programmed independently allowing unique values of

gain and offset for each of the six channels. A 2-to-1

multiplexing scheme routes the signals to three 70

MHz high performance ADCs. The fully differential

processing channels achieve exceptional noise

immunity, having a very low noise floor of –68.5dB.

The 10-bit analog-to-digital converters have excellent dynamic performance, making the LM98620

transparent in the image reproduction chain.