2 LC MOS Single Supply, a 12-Bit 600 kSPS ADC AD7892 FEATURES FUNCTIONAL BLOCK DIAGRAM Fast 12-Bit ADC with 1.47 s Conversion Time REF OUT/REF IN V DD 600 kSPS Throughput Rate (AD7892-3) 500 kSPS Throughput Rate (AD7892-1, AD7892-2) 2k +2.5V MODE Single Supply Operation AD7892 REFERENCE On-Chip Track/Hold Amplifier Selection of Input Ranges: DB0 10 V or 5 V for AD7892-1 DB2 0 V to +2.5 V for AD7892-2 DB3/RFS 12-BIT DB4/SCLK 2.5 V for AD7892-3 ADC DB5/SDATA V High Speed Serial and Parallel Interface IN1 SIGNAL DB10/LOW SCALING V Low Power, 60 mW typ IN2 DB11/LOW Overvoltage Protection on Analog Inputs (AD7892-1 TRACK/HOLD and AD7892-3) CLOCK CONTROL LOGIC CS RD EOC CONVST AGND DGND STANDBY GENERAL DESCRIPTION The AD7892 is fabricated in Analog Devices Linear Compat- 2 The AD7892 is a high speed, low power, 12-bit A/D converter ible CMOS (LC MOS) process, a mixed technology process that operates from a single +5 V supply. The part contains a that combines precision bipolar circuits with low power CMOS 1.47 s successive approximation ADC, an on-chip track/hold logic. It is available in a 24-lead, 0.3 wide, plastic or hermetic amplifier, an internal +2.5 V reference and on-chip versatile DIP or in a 24-lead SOIC. interface structures that allow both serial and parallel connec- tion to a microprocessor. The part accepts an analog input range PRODUCT HIGHLIGHTS of 10 V or 5 V (AD7892-1), 0 V to +2.5 V (AD7892-2) and 1. The AD7892-3 features a conversion time of 1.47 s and a 2.5 V (AD7892-3). Overvoltage protection on the analog inputs track/hold acquisition time of 200 ns. This allows a through- for the AD7892-1 and AD7892-3 allows the input voltage to go put rate for the part up to 600 kSPS. The AD7892-1 and to 17 V or 7 V respectively without damaging the ports. AD7892-2 operate with throughput rates of 500 kSPS. The AD7892 offers a choice of two data output formats: a 2. The AD7892 operates from a single +5 V supply and con- single, parallel, 12-bit word or serial data. Fast bus access times sumes 60 mW typ making it ideal for low power and portable and standard control inputs ensure easy parallel interface to applications. microprocessors and digital signal processors. A high speed 3. The part offers a high speed, flexible interface arrangement serial interface allows direct connection to the serial ports of with parallel and serial interfaces for easy connection to microcontrollers and digital signal processors. microprocessors, microcontrollers and digital signal In addition to the traditional dc accuracy specifications such as processors. linearity, full-scale and offset errors, the part is also specified for dynamic performance parameters including harmonic distortion and signal-to-noise ratio. REV. C Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. use, nor for any infringements of patents or other rights of third parties Tel: 781/329-4700 World Wide Web Site: (V = +5 V 5%, AGND = DGND = 0 V, REF IN = +2.5 V. All specifications T to T DD MIN MAX AD7892SPECIFICATIONS unless otherwise noted.) 1 2 Parameter A Versions B Versions S Version Unit Test Conditions/Comments DYNAMIC PERFORMANCE AD7892-1, AD7892-2 f = 100 kHz. f = 500 kSPS IN SAMPLE 3 Signal to (Noise + Distortion) Ratio 70 70 70 dB min 3 Total Harmonic Distortion 78 78 78 dB max typ 84 dB 3 Peak Harmonic or Spurious Noise 79 79 79 dB max 3 Intermodulation Distortion fa = 49 kHz, fb = 50 kHz 2nd Order Terms 78 78 78 dB max typ 84 dB 3rd Order Terms 78 78 78 dB max typ 84 dB AD7892-3 f = 100 kHz. f = 600 kSPS IN SAMPLE 3 Signal to (Noise + Distortion) Ratio 70 70 dB min 3 Total Harmonic Distortion 78 78 dB max 3 Peak Harmonic or Spurious Noise 79 79 dB max 3 Intermodulation Distortion fa = 49 kHz, fb = 50 kHz 2nd Order Terms 78 78 dB max 3rd Order Terms 78 78 dB max DC ACCURACY Resolution 12 12 12 Bits Minimum Resolution for Which No Missing Codes Are Guaranteed 12 12 12 Bits 3 Relative Accuracy 1.5 1 1 LSB max 3 Differential Nonlinearity 1 1 1 LSB max AD7892-1 3 Positive Full-Scale Error 4 4 5 LSB max 3 Negative Full-Scale Error 4 4 5 LSB max 3 Bipolar Zero Error 3 2 3 LSB max AD7892-3 3 Positive Full-Scale Error 4 4 LSB max 3 Negative Full-Scale Error 4 4 LSB max 3 Bipolar Zero Error 4 3 LSB max AD7892-2 3 Positive Full-Scale Error 5 5 5 LSB max 3 Unipolar Offset Error 4 3 4 LSB max ANALOG INPUT AD7892-1 Input Voltage Range 10 10 10 Volts Input Applied to V with V Grounded IN1 IN2 Input Voltage Range 5 5 5 Volts Input Applied to V and V IN1 IN2 Input Resistance 8 8 8 k min Input Applied to V with V Grounded IN1 IN2 AD7892-2 Input Voltage Range on V 0 to +2.5 0 to +2.5 0 to +2.5 Volts Input Applied to V IN1 IN1 Input Current 10 10 50 nA max Input Voltage Range on V 50 50 50 mV max IN2 AD7892-3 Input Voltage Range on V 2.5 2.5 Volts Input Applied to V IN1 IN1 Input Resistance 2 2 k min REFERENCE OUTPUT/INPUT REF IN Input Voltage Range 2.375/2.625 2.375/2.625 2.375/2.625 V min/V max 2.5 V 5% Input Impedance 1.6 1.6 1.6 k min Resistor Connected to Internal Reference Node 4 Input Capacitance 10 10 10 pF max REF OUT Output Voltage 2.5 2.5 2.5 V nom REF OUT Error +25C 10 10 10 mV max T to T 20 20 25 mV max MIN MAX REF OUT Temperature Coefficient 25 25 25 ppm/C typ REF OUT Output Impedance 5.5 5.5 5.5 k nom LOGIC INPUTS Input High Voltage, V 2.4 2.4 2.4 V min V = 5 V 5% INH DD Input Low Voltage, V 0.8 0.8 0.8 V max V = 5 V 5% INL DD Input Current, I 10 10 10 A max V = 0 V to V IN IN DD 4 Input Capacitance, C 10 10 10 pF max IN 2 REV. 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