LTC1272 12-Bit, 3s, 250kHz Sampling A/D Converter FEATURES DESCRIPTION n AD7572 Pinout The LTC1272 is a 3s, 12-bit, successive approximation n 12-Bit Resolution sampling A/D converter. It has the same pinout as the n 3s and 8s 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 (Pin23, 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 operation, it provides a 2.42V reference output instead of APPLICATIONS 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 1s sample- n Digital Signal Processing (DSP) and-hold acquisition time is allowed between conversions. n Multiplexed Data Acquisition Systems n The output data can be read as a 12-bit word or as two Single Supply Systems 8-bit bytes. This allows easy interface to both 8-bit and L, 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, 3s, 12-Bit Sampling ADC 1024 Point FFT, f = 250kHz, f = 10kHz S IN 5V LTC1272 0 ANALOG INPUT A V IN DD (0V TO 5V) 2.42V 20 S + = 72.1 V V NC REF REF (N+D) + 10F 0.1F OUTPUT 10F 0.1F AGND BUSY 40 D11 (MSB) CS 60 P D10 RD CONTROL LINES 80 D9 HBEN D8 CLK OUT 100 D7 CLK IN 120 D6 D0/8 8 OR 12-BIT PARALLEL 140 D5 D1/9 BUS 0 20 40 60 80 100 120 D4 D2/10 FREQUENCY (kHz) DGND D3/11 LTC1272 F02 LTC1272 F01 1272fc 1 For more information www.linear.com/1272 AMPLITUDE (dB)LTC1272 ABSOLUTE MAXIMUM RATINGS (Notes 1 and 2) Supply Voltage (V ) ..................................................6V Operating Temperature Range DD Analog Input Voltage (Note 3) ....................0.3V to 15V LTC1272-XAC, CC .................................... 0C to 70C Digital Input Voltage ...................................0.3V to 12V Storage Temperature Range ...................65C to 150C Digital Output Voltage .....................0.3V to V + 0.3V Lead Temperature (Soldering, 10 sec) .................. 300C DD Power Dissipation ...............................................500mW PIN CONFIGURATION TOP VIEW TOP VIEW A 1 24 V A 1 24 V IN DD IN DD V 2 23 NC V 2 23 NC REF REF AGND 3 22 BUSY AGND 3 22 BUSY (MSB) D11 4 21 CS (MSB) D11 4 21 CS D10 5 20 RD D10 5 20 RD D9 6 19 HBEN D9 6 19 HBEN D8 7 18 CLK OUT D8 7 18 CLK OUT D7 8 17 CLK IN D7 8 17 CLK IN D6 9 16 D0/8 D6 9 16 D0/8 D5 10 15 D1/9 D5 10 15 D1/9 D4 11 14 D2/10 D4 11 14 D2/10 DGND 12 13 D3/11 DGND 12 13 D3/11 N PACKAGE SW PACKAGE 24-LEAD PDIP 24-LEAD PLASTIC SO WIDE T = 110C, = 100C/W T = 110C, = 130C/W JMAX JA JMAX JA ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC1272ACN-3 PBF LTC1272ACN-3 TRPBF LTC1272-3ACN 24-Lead PDIP 0C to 70C LTC1272CCN-3 PBF LTC1272CCN-3 TRPBF LTC1272-3CCN 24-Lead PDIP 0C to 70C LTC1272ACN-8 PBF LTC1272ACN-8 TRPBF LTC1272-8ACN 24-Lead PDIP 0C to 70C LTC1272CCN-8 PBF LTC1272CCN-8 TRPBF LTC1272-8CCN 24-Lead PDIP 0C to 70C LTC1272ACSW-3 PBF LTC1272ACSW-3 TRPBF LTC1272-3ACSW 24-Lead Plastic SO Wide 0C to 70C LTC1272CCSW-3 PBF LTC1272CCSW-3 TRPBF LTC1272-3CCSW 24-Lead Plastic SO Wide 0C to 70C LTC1272ACSW-8 PBF LTC1272ACSW-8 TRPBF LTC1272-8ACSW 24-Lead Plastic SO Wide 0C to 70C LTC1272CCSW-8 PBF LTC1272CCSW-8 TRPBF LTC1272-8CCSW 24-Lead Plastic SO Wide 0C to 70C Consult LTC Marketing for parts specified with wider operating temperature ranges. Consult LTC Marketing for information on nonstandard lead based finish parts. For more information on lead free part marking, go to: