Datasheet LTC1272 (Analog Devices)

LTC1272 12-Bit, 3µs, 250kHz Sampling A/D Converter
FEATURES DESCRIPTION
n AD7572 Pinout The LTC1272 is a 3µs, 12-bit, successive approximation n 12-Bit Resolution sampling A/D converter. It has the same pinout as the n 3µs and 8µs Conversion Times industry standard AD7572 and offers faster conversion n On-Chip Sample-and-Hold time, on-chip sample-and-hold, and single supply opera- n Up to 250kHz Sample Rates tion. It uses LTBiCMOS™ switched-capacitor technology n 5V Single Supply Operation to combine a high speed 12-bit ADC with a fast, accurate n No Negative Supply Required sample-and-hold and a precision reference. n On-Chip 25ppm/°C Reference The LTC1272 operates with a single 5V supply but can n 75mW (Typ) Power Consumption also accept the 5V/–15V supplies required by the AD7572 n ESD Protected on All Pins (Pin 23, the negative supply pin of the AD7572, is not con- n 24-Pin Narrow DIP and SOL Packages nected on the LTC1272). The LTC1272 has the same 0V to 5V input range as the AD7572 but, to achieve single supply
APPLICATIONS
operation, it provides a 2.42V reference output instead of the –5.25V of the AD7572. It plugs in for the AD7572 if the n High Speed Data Acquisition reference capacitor polarity is reversed and a 1µs sample- n Digital Signal Processing (DSP) and-hold acquisition time is allowed between conversions. n Multiplexed Data Acquisition Systems n Single Supply Systems The output data can be read as a 12-bit word or as two L 8-bit bytes. This allows easy interface to both 8-bit and , LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and LTBiCMOS is a trademark of Linear Technology Corporation. All other trademarks are the higher processors. The LTC1272 can be used with a crystal property of their respective owners. or an external clock and comes in speed grades of 3ms and 8ms.
TYPICAL APPLICATION Single 5V Supply, 3µs, 12-Bit Sampling ADC 1024 Point FFT, fS = 250kHz, fIN = 10kHz
LTC1272 5V 0 ANALOG INPUT A IN VDD 2.42V (0V TO 5V) + –20 V S REF REF V NC + 10µF 0.1µF (N+D) = 72.1 OUTPUT 0.1µF 10µF AGND BUSY –40 D11 (MSB) CS µP –60 D10 RD CONTROL LINES D9 HBEN –80 AMPLITUDE (dB) D8 CLK OUT –100 D7 CLK IN –120 D6 8 OR 12-BIT D0/8 PARALLEL D5 D1/9 BUS –140 0 20 40 60 80 100 120 D4 D2/10 FREQUENCY (kHz) DGND D3/11 LTC1272 • F02 LTC1272 • F01 1272fc For more information www.linear.com/1272 1 Document Outline FEATURES APPLICATIONS DESCRIPTION TYPICAL APPLICATION ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION ORDER INFORMATION CONVERTER CHARACTERISTICS INTERNAL REFERENCE CHARACTERISTICS DIGITAL AND DC ELECTRICAL CHARACTERISTICS DYNAMIC ACCURACY ANALOG INPUT TIMING CHARACTERISTICS PIN FUNCTIONS TYPICAL PERFORMANCE CHARACTERISTICS APPLICATIONS INFORMATION REVISION HISTORY PACKAGE DESCRIPTION