XRD87L85 Datasheet, PDF (1/15 Pages) Exar Corporation – Low-Voltage CMOS 8-Bit High-Speed Analog-to-Digital Converter

FEATURES
• 8-Bit Resolution
• Up to 10 MHz Sampling Rate
• Internal S/H Function
• Single Supply: 3.3V
• VIN DC Range: 0V to V_DD
• VREF DC Range: 1V to V_DD
• Low Power: 25mW typ. (excluding reference)
XRD87L85
Low-Voltage CMOS 8-Bit High-Speed
Analog-to-Digital Converter
April 2002-1
• Latch-Up Free
• ESD Protection: 2000V Minimum
• 20-Pin Package Available: XRD87L75
APPLICATIONS
• Digital Color Copiers
• Cellular Telephones
• CCDs and Scanners
• Video Capture Boards
GENERAL DESCRIPTION
The XRD87L85 is an 8-bit Analog-to-Digital Converter.
Designed using an advanced 3.3V CMOS process,
this part offers excellent performance, low power con-
sumption, and latch-up free operation.
This device uses a two-step flash architecture to
maintain low power consumption at high conversion
rates. The input circuitry of the XRD87L85 includes an
on-chip S/H function which allows the user to digitize
analog input signals between AGND and AV_DD. Careful
design and chip layout have achieved a low analog
input capacitance. This reduces “kickback” and eases
the requirements of the buffer/amplifier used to drive
the XRD87L85. The designer can choose the internally
generated reference voltages by connecting V_RB to
SIMPLIFIED BLOCK AND TIMING DIAGRAM
V_RBS and V_RT to V_RTS, or provide external reference
voltages to the V_RB and V_RT pins. The internal reference
generates 0.4V at V_RB and 1.72V at V_RT. Providing
external reference voltages allows easy interface to
any input signal range between AGND and AV_DD. This
also allows the system to adjust these voltages to
cancel zero scale and full scale errors, or to change the
input range as needed.
The device operates from a single +3.3V supply.
Power consumption is 25mW at FS = 6MHz. Specified
for operation over the commercial/industrial (–40 to
+85°C) temperature range, the XRD87L85 is available
in Plastic Dual-in-line (PDIP), Surface Mount (SOIC)
and Small Outline (SOP) packages in EIAJ and
JEDEC.
Rev. 1.00
EXAR Corporation, 48720 Kato Road, Fremont, CA 94538 • [phone] • FAX [phone]