S/(N+D) (dB) LTC1278 12-Bit, 500ksps Sampling A/D Converter with Shutdown DESCRIPTIO FEATURES n Single Supply 5V or 5V Operation The LTC 1278 is a 1.6s, 500ksps, sampling 12-bit A/D n Two Speed Grades,500ksps (LTC1278-5) converter that draws only 75mW from a single 5V or 5V 400ksps (LTC1278-4) supplies. This easy-to-use device comes complete with n 70dB S/(N + D) and 74dB THD at Nyquist a 200ns sample-and-hold, a precision reference and an n No Missing Codes Over Temperature internally trimmed clock. Unipolar and bipolar conver- n 75mW (Typ) Power Dissipation sion modes add to the flexibility of the ADC. The low n Power Shutdown with Instant Wake-Up power dissipation is made even more attractive by a n Internal Reference Can Be Overdriven Externally 8.5mW power-down feature. Instant wake-up from shut- n Internal Synchronized Clock No Clock Required down allows the converter to be powered down even n High Impedance Analog Input during brief inactive periods. n 0V to 5V or 2.5V Input Range The LTC1278 converts 0V to 5V unipolar inputs from a n New Flexible, Friendly Parallel Interface to DSPs single 5V supply and 2.5V bipolar inputs from 5V and FIFOs supplies. Maximum DC specs include 1LSB INL and n 24-Pin Narrow PDIP and SW Packages 1LSB DNL. Outstanding guaranteed AC performance includes 70dB S/(N + D) and 78dB THD at the input APPLICATI S frequency of 100kHz over temperature. n High Speed Data Acquisition The internal clock is trimmed for 1.6s conversion time. n Digital Signal Processing The clock automatically synchronizes to each sample n Multiplexed Data Acquisition Systems command, eliminating problems with asynchronous clock n Audio and Telecom Processing noise found in competitive devices. A separate convert n Spectrum Analysis start input and a data ready signal (BUSY) ease connec- , LTC and LT are registered trademarks of Linear Technology Corporation. tions to FIFOs, DSPs and microprocessors. TYPICAL APPLICATI Single 5V Supply, 500kHz, 12-Bit Sampling A/D Converter Effective Bits and Signal-to-(Noise + Distortion) vs Input Frequency LTC1278-5 5V 24 1 ANALOG INPUT A AV 12 74 IN DD 2.42V (0V TO 5V) + 2 23 V V 0.1F 11 68 REFERENCE REF SS 10F + 3 22 OUTPUT 0.1F AGND BUSY 10 62 NYQUIST 10F 4 21 P CONTROL 9 FREQUENCY 56 D11(MSB) CS 5 20 LINES D10 RD 8 6 19 D9 CONVST CONVERSION START INPUT 7 7 18 6 D8 SHDN POWER DOWN INPUT 17 8 D7 DV 5 DD 9 16 D6 D0 4 10 15 12-BIT D5 D1 3 PARALLEL 11 14 2 BUS D4 D2 12 13 DGND D3 1 f = 500kHz SAMPLE 0 10k 100k 1M 2M INPUT FREQUENCY (Hz) LT1278 G4 LTC1278 TA01 1 EFFECTIVE NUMBER OF BITS UO UO ULTC1278 O ABS LUTEXAI U RATI GS PACKAGE/ORDER I FOR ATIO AV = DV = V (Notes 1, 2) DD DD DD ORDER TOP VIEW Supply Voltage (V ) .............................................. 12V DD PART NUMBER A 1 AV 24 IN DD Negative Supply Voltage (V ) SS V 2 V 23 REF SS Bipolar Operation Only .......................... 6V to GND LTC1278-4CN AGND 3 BUSY 22 D11 (MSB) 4 CS 21 Total Supply Voltage (V to V ) LTC1278-5CN DD SS D10 5 RD 20 Bipolar Operation Only ....................................... 12V LTC1278-4IN D9 6 CONVST 19 Analog Input Voltage (Note 3) LTC1278-4CSW D8 7 SHDN 18 Unipolar Operation ................... 0.3V to V + 0.3V D7 8 DV LTC1278-5CSW 17 DD DD D6 9 D0 16 Bipolar Operation............... V 0.3V to V + 0.3V LTC1278-4ISW SS DD D5 10 D1 15 Digital Input Voltage (Note 4) D4 11 D2 14 Unipolar Operation ................................0.3V to 12V DGND 12 13 D3 Bipolar Operation........................... V 0.3V to 12V SS N PACKAGE SW PACKAGE 24-LEAD PDIP 24-LEAD PLASTIC SO WIDE Digital Output Voltage T = 110C, = 100C/W (N) JMAX JA Unipolar Operation ................... 0.3V to V + 0.3V DD T = 110C, = 130C/W (SW) JMAX JA Bipolar Operation................ V 0.3V to V + 0.3V SS DD Power Dissipation ............................................. 500mW Consult factory for Military grade parts. Operating Temperature Range LTC1278-4C, LTC1278-5C ..................... 0C to 70C LTC1278-4I ....................................... 40C to 85C Storage Temperature Range ................ 65C to 150C Lead Temperature (Soldering, 10 sec)................. 300C With Internal Reference (Notes 5, 6) CO VERTERCCHARA TERISTICS LTC1278-4/LTC1278-5 PARAMETER CONDITIONS MIN TYP MAX UNITS Resolution (No Missing Codes) l 12 Bit Integral Linearity Error (Note 7) l 1 LSB Differential Linearity Error l 1 LSB Offset Error (Note 8) 4 LSB l 6 LSB Gain Error 15 LSB Gain Error Tempco I = 0 l 10 45 ppm/C OUT(REF) (Note 5) A ALOG I PUT LTC1278-4/LTC1278-5 SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V Analog Input Range (Note 9) 4.95V V 5.25V (Unipolar) l 0 to 5 V IN DD 4.75V V 5.25V, 5.25V V 2.45V (Bipolar) l 2.5 V DD SS I Analog Input Leakage Current CS = High l 1 A IN C Analog Input Capacitance Between Conversions (Sample Mode) 45 pF IN During Conversions (Hold Mode) 5 pF 2 U U U U WU U W W W