Preliminary XRD64L43 Dual 10-Bit 40MSPS CMOS ADC July 2003 APPLICATIONS FEATURES Medical Imaging 10-Bit Resolution Instrumentation Two Monolithic Complete 10-Bit ADCs Data Aquisition Systems 40 MSPS Conversion Rate On-Chip Track-and-Hold Digital Comunications On-Chip Voltage Reference BENEFITS Low 5 pF Input Capacitance TTL/CMOS Outputs Reduction of Components Tri-State Output Buffers Reduction of System Cost Single +3.0V Power Supply Operation High Performance Low Power Dissipation Low Power Dissipation: 200mW-typ 2.7V Long Term Time and Temperature Stability Power Down Mode Less Than 5mW 75dB Crosstalk (fin=1.0MHz) -40C to +85C Operation Temperature Range GENERAL DESCRIPTION The XRD64L43 is two 10-bit, monolithic, 40 MSPS user after the initial 4.2ms calibration (168,000 initial clock cycles). ADCs. Manufactured using a standard CMOS pro- cess, the XRD64L43 offers low power, low cost and excellent performance. The on-chip track-and-hold The power dissipation is only 200mW at 40 MSPS with +2.7V power supply. amplifier(T/H) and voltage reference (VREF) eliminate the need for external active components, requiring only an external ADC conversion clock for the application. The digital output data is straight binary format, and the tri- The XRD64L43 analog input can be driven with ease state disable function is provided for common bus interface. due to the high input impedance. The XRD64L43 internal reference provides cost savings The design architecture uses 17 time- interleaved 10- and simplifies the design/development. The output voltage bit SAR ADCs in each converter to achieve high of the internal reference is set by two external resistors. The conversion rate of 40 MSPS minimum. In order to internal reference can be disabled if an external reference is insure and maintain accurate 10-bit operation with used for a power savings of 50mW. respect to time and temperature, XRD64L43 incorpo- rates an auto-calibration circuit which continuously adjusts and matches the offset and linearity of each ADC. This auto-calibration circuit is transparent to the ORDERING INFORMATION Part Number Package Type Temperature Range XRD64L43AIV 64-Lead LQFP -40C to +85C Rev. P1.00 EXAR Corporation, 48720 Kato Road, Fremont, CA 94538 (510) 668-7000 FAX (510) 668-7017XRD64L43 Preliminary VINA+VINA- 10 Bit A/D s ADC A Bandgap A/D 1a VBG + DA9 - DA0, 11 VFBK - OTRA VRHF TRI A A/D 17a VRHS DIFF SYNCO K PD CONTROL LOGIC CKIN VRLS 10 Bit A/D s ADC B A/D 1b VRLF DB9 - DB0, 11 OTRB + VCMO - TRI B A/D 17b VINB+VINB- Figure 1. XRD64L43 Simplified Block Diagram Rev. P1.00 2