AD7880BRZ Analog Devices

2 LC MOS Single +5 V Supply, a Low Power, 12-Bit Sampling ADC AD7880 FEATURES FUNCTIONAL BLOCK DIAGRAM 12-Bit Monolithic A/D Converter 66 kHz Throughput Rate V DD 12 ms Conversion Time 3 ms On-Chip Track/Hold Amplifier SAMPLING R V COMPARATOR LOW POWER MODE INA Low Power CONTROL + Power Save Mode: 2 mW typ R CIRCUIT V INB Normal Operation: 25 mW typ 70 dB SNR V REF 12-BIT DAC Fast Data Access Time: 57 ns AGND Small 24-Lead SOIC and 0.3 DIP Packages CS SAR + APPLICATIONS CLKIN COUNTER CONTROL Battery Powered Portable Systems CONVST LOGIC Digital Signal Processing RD THREE BUSY Speech Recognition and Synthesis STATE AD7880 BUFFERS High Speed Modems Control and Instrumentation DB11 DB0 DGND GENERAL DESCRIPTION PRODUCT HIGHLIGHTS The AD7880 is a high speed, low power, 12-bit A/D converter 1. Fast Conversion Time. which operates from a single +5 V supply. It consists of a 3 s 12 s conversion time and 3 s acquisition time allow for track/hold amplifier, a 12 s successive-approximation ADC, large input signal bandwidth. This performance is ideally versatile interface logic and a multiple-input-range circuit. The suited for applications in areas such as telecommunications, part also includes a power save feature. audio, sonar and radar signal processing. An internal resistor network allows the part to accept both uni- 2. Low Power Consumption. polar and bipolar input signals while operating from a single 2 mW power consumption in the power-down mode makes +5 V supply. Fast bus access times and standard control inputs the part ideally suited for portable, hand held, battery pow- ensure easy interfacing to modern microprocessors and digital ered applications. signal processors. 3. Multiple Input Ranges. The AD7880 features a total throughput time of 15 s and can The part features three user-determined input ranges, 0 V to convert full power signals up to 33 kHz with a sampling fre- +5 V, 0 V to 10 V and 5 V. These unipolar and bipolar quency of 66 kHz. ranges are achieved with a 5 V only power supply. In addition to the traditional dc accuracy specifications such as linearity, full-scale and offset errors, the AD7880 is also fully specified for dynamic performance parameters including har- monic distortion and signal-to-noise ratio. The AD7880 is fabricated in Analog Devices Linear Compat- 2 ible CMOS (LC MOS) process, a mixed technology process that combines precision bipolar circuits with low power CMOS logic. The part is available in a 24-pin, 0.3 inch-wide, plastic or hermetic dual-in-line package (DIP) as well as a small 24-lead SOIC package. REV. 0 Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Tel: 617/329-4700 Fax: 617/326-8703(V = +5 V 6 5%, V = V , AGND = DGND = O V, f = 2.5 MHz, MODE = V DD REF DD CLKIN DD AD7880SPECIFICATIONS unless otherwise noted. All Specifications T to T unless otherwise noted.) MIN MAX 1 1 Parameter B Versions C Versions Units Test Conditions/Comments 2 DYNAMIC PERFORMANCE 3 Signal-to-Noise Ratio (SNR) 70 70 dB min Typically SNR Is 72 dB V = 1 kHz Sine Wave, f = 66 kHz IN SAMPLE Total Harmonic Distortion (THD) 80 80 dB typ V = 1 kHz Sine Wave, f = 66 kHz IN SAMPLE Peak Harmonic or Spurious Noise 80 80 dB typ V = 1 kHz, f = 66 kHz IN SAMPLE Intermodulation Distortion (IMD) = 66 kHz Second Order Terms 80 80 dB typ fa = 0.983 kHz, fb = 1.05 kHz, f SAMPLE Third Order Terms 80 80 dB typ fa = 0.983 kHz, fb = 1.05 kHz, f = 66 kHz SAMPLE DC ACCURACY Resolution 12 12 Bits All DC ACCURACY Specifications Apply for the Three Analog Input Ranges Integral Nonlinearity 1 1 LSB max Differential Nonlinearity 1 1 LSB max Guaranteed Monotonic Full-Scale Error 15 5 LSB max Bipolar Zero Error 10 5 LSB max Unipolar Offset Error 5 5 LSB max ANALOG INPUT Input Voltage Ranges 0 to V 0 to V Volts See Figure 5 REF REF 0 to 2 V 0 to 2 V Volts See Figure 6 REF REF V V Volts See Figure 7 REF REF Input Resistance 10 10 M min 0 to V Range REF 5/12 5/12 k min/max 8 k typical: 0 to 2 V Range REF 5/12 5/12 k min/max 8 k typical: V Range REF REFERENCE INPUT V (For Specified Performance) 5 5 V 5%: Normally V = V (See Reference Input Section) REF REF DD I 1.5 1.5 mA max REF Nominal Reference Range 2.5/V 2.5/V V min/max See Figure 3 for Degradation in Performance Down to 2.5 V DD DD LOGIC INPUTS CONVST, RD, CS, CLKIN Input High Voltage, V 2.4 2.4 V min INH Input Low Voltage, V 0.8 0.8 V max INL Input Current, I 10 10 A max V = 0 V or V IN IN DD 4 Input Capacitance, C 10 10 pF max IN MODE INPUT Input High Voltage, V 4 4 V min INH Input Low Voltage, V 1 1 V max INL Input Current, I 125 125 A max V = 0 V or V IN IN DD 4 Input Capacitance, C 10 10 pF max IN LOGIC OUTPUTS DB11DB0, BUSY Output High Voltage, V 4.0 4.0 V min I = 400 A OH SOURCE Output Low Voltage, V 0.4 0.4 V max I = 1.6 mA OL SINK DB11DB0 Floating-State Leakage Current 10 10 A max 4 Floating-State Output Capacitance 10 10 pF max CONVERSION Conversion Time 12 12 s max f = 2.5 MHz CLKIN Track/Hold Acquisition Time 3 3 s max POWER REQUIREMENTS V +5 +5 V nom 5% for Specified Performance DD I DD Normal Power Mode +25C 7.5 7.5 mA max Typically 4 mA MODE = V DD T to T 10 10 mA max Typically 5 mA MODE = V MIN MAX DD Power Save Mode +25C 750 750 A max Logic Inputs 0 V or V MODE = 0 V DD T to T 1 1 mA max Logic Inputs 0 V or V MODE = 0 V MIN MAX DD Power Dissipation Normal Power Mode +25C 37.5 37.5 mW max V = 5 V: Typically 20 mW MODE = V DD DD T to T 50 50 mW max V = 5 V: Typically 25 mW MODE = V MIN MAX DD DD Power Save Mode +25C 3.75 3.75 mW max V = 5 V: Typically 2 mW MODE = 0 V DD T to T 5 5 mW max V = 5 V: Typically 2.5 mW MODE = 0 V MIN MAX DD NOTES 1 Temperature ranges are as follows: B/C Versions, 40C to +85C. 2 V = 0 to V IN REF 3 SNR calculation includes distortion and noise components. 4 Sample tested +25C to ensure compliance. Specifications subject to change without notice. 2 REV. 0