
EXAR Corporation, 48720 Kato Road, Fremont, CA 94538
(510) 668-7000 FAX (510) 668-7017
Rev. P1.00
Preliminary
Dual 10-Bit 40MSPS CMOS ADC
July 2003
FEATURES
10-Bit Resolution
Two Monolithic Complete 10-Bit ADCs
40MSPSConversionRate
On-ChipTrack-and-Hold
On-ChipVoltageReference
Low 5 pF Input Capacitance
TTL/CMOS Outputs
Tri-State Output Buffers
Single +3.0V Power Supply Operation
Low Power Dissipation: 200mW-typ @ 2.7V
Power Down Mode Less Than 5mW
75dB Crosstalk (fin=1.0MHz)
-40°Cto+85°COperationTemperatureRange
APPLICATIONS
MedicalImaging
Instrumentation
DataAquisitionSystems
DigitalComunications
BENEFITS
ReductionofComponents
Reduction of System Cost
High Performance @ Low Power Dissipation
Long Term Time and Temperature Stability
GENERAL DESCRIPTION
The XRD64L43 is two 10-bit, monolithic, 40 MSPS
ADCs. Manufactured using a standard CMOS pro-
cess, the XRD64L43 offers low power, low cost and
excellent performance. The on-chip track-and-hold
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 XRD64L43 analog input can be driven with ease
due to the high input impedance.
The design architecture uses 17 time- interleaved 10-
bit SAR ADCs in each converter to achieve high
conversion rate of 40 MSPS minimum. In order to
insure and maintain accurate 10-bit operation with
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
user after the initial 4.2ms calibration (168,000 initial clock
cycles).
Thepowerdissipationisonly200mWat40MSPSwith+2.7V
power supply.
The digital output data is straight binary format, and the tri-
statedisablefunctionisprovidedforcommonbusinterface.
The XRD64L43 internal reference provides cost savings
andsimplifiesthedesign/development.Theoutputvoltage
oftheinternalreferenceissetbytwoexternalresistors.The
internalreferencecanbedisabledifanexternalreferenceis
used for a power savings of 50mW.
ORDERING INFORMATION
Part Number
Package Type
Temperature Range
XRD64L43AIV
64-Lead LQFP
-40°C to +85°C
XRD64L43