2.7 V to 5.5 V, 400 kSPS a 8-/10-Bit Sampling ADC AD7813 FUNCTIONAL BLOCK DIAGRAM FEATURES 8-/10-Bit ADC with 2.3 s Conversion Time On-Chip Track and Hold V V DD AGND REF Operating Supply Range: 2.7 V to 5.5 V Specifications at 2.7 V3.6 V and 5 V 10% DB7 AD7813 CHARGE 8-Bit Parallel Interface THREE- REDISTRIBUTION 8-Bit + 2-Bit Read STATE DAC DRIVERS Power Performance CLOCK DB0 Normal Operation OSC 10.5 mW, V = 3 V DD Automatic Power-Down CONTROL COMP V T/H IN LOGIC 34.6 W 1 kSPS, V = 3 V DD Analog Input Range: 0 V to V REF Reference Input Range: 1.2 V to V DD BUSY CS RD CONVST GENERAL DESCRIPTION PRODUCT HIGHLIGHTS The AD7813 is a high-speed, microprocessor-compatible, 1. Low Power, Single Supply Operation 8-/10-bit analog-to-digital converter with a maximum through- The AD7813 operates from a single 2.7 V to 5.5 V supply put of 400 kSPS. The converter operates off a single 2.7 V to and typically consumes only 10.5 mW of power. The power 5.5 V supply and contains a 2.3 s successive approximation dissipation can be significantly reduced at lower through- A/D converter, track/hold circuitry, on-chip clock oscillator and put rates by using the automatic power-down mode. 8-bit wide parallel interface. The parallel interface is designed to 2. Automatic Power-Down allow easy interfacing to microprocessors and DSPs. The 10-bit The automatic power-down mode, whereby the AD7813 conversion result is read by carrying out two 8-bit read opera- goes into power-down mode at the end of a conversion and tions. The first read operation accesses the 8 MSBs of the ADC powers up before the next conversion, means the AD7813 conversion result and the second read accesses the 2 LSBs. is ideal for battery powered applications e.g., 34.6 W Using only address decoding logic the AD7813 is easily mapped 1 kSPS. (See Power vs. Throughput Rate section.) into the microprocessor address space. 3. Parallel Interface When used in its power-down mode, the AD7813 automatically An easy to use 8-bit-wide parallel interface allows interfacing powers down at the end of a conversion and powers up at the to most popular microprocessors and DSPs with minimal start of a new conversion. This feature significantly reduces the external circuitry. power consumption of the part at lower throughput rates. The 4. Dynamic Specifications for DSP Users AD7813 can also operate in a high speed mode where the part is In addition to the traditional ADC specifications, the AD7813 not powered down between conversions. In this mode of opera- is specified for ac parameters, including signal-to-noise ratio tion the part is capable of providing 400 kSPS throughput. and distortion. The part is available in a small, 16-lead, 0.3 wide, plastic dual- in-line package (DIP), in a 16-lead, 0.15 wide, narrow body small outline IC (SOIC) and in a 16-lead thin shrink small outline package (TSSOP). 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: (GND = 0 V, V = V = 3 V 10% to 5 V 10%. All specifications 40 C to REF DD 1 +105 C unless otherwise noted.) AD7813SPECIFICATIONS Parameter Y Version Unit Test Conditions/Comments DYNAMIC PERFORMANCE f = 30 kHz, f = 350 kHz IN SAMPLE 1 Signal to (Noise + Distortion) Ratio 58 dB min 1 Total Harmonic Distortion (THD) 66 dB max 1 Peak Harmonic or Spurious Noise 66 dB max 2 Intermodulation Distortion fa = 29.1 kHz, fb = 29.8 kHz 2nd Order Terms 67 dB typ 3rd Order Terms 67 dB typ DC ACCURACY Resolution 10 Bits Minimum Resolution for Which No Missing Codes Are Guaranteed 10 Bits 1 Relative Accuracy 1 LSB max 1 Differential Nonlinearity (DNL) 1 LSB max 1 Gain Error 2 LSB max 1 Offset Error 2.0 LSB max ANALOG INPUT Input Voltage Range 0 V min V V max REF 2 Input Leakage Current 1 A max 2 Input Capacitance 20 pF max 2 REFERENCE INPUTS V Input Voltage Range 1.2 V min REF V V max DD Input Leakage Current 3 A max Input Capacitance 15 pF max 2 LOGIC INPUTS V Input High Voltage 2.0 V min INH, V Input Low Voltage 0.4 V max (0.8 V max, V = 5 V) INL, DD Input Current, I 1 A max Typically 10 nA, V = 0 V to V IN IN DD Input Capacitance, C 8 pF max IN LOGIC OUTPUTS Output High Voltage, V 2.4 V min I = 200 A OH SOURCE Output Low Voltage, V 0.4 V max I = 200 A OL SINK High Impedance Leakage Current 1 A max High Impedance Capacitance 15 pF max CONVERSION RATE Conversion Time 2.3 s max 1 Track/Hold Acquisition Time 100 ns max POWER SUPPLY V 2.75.5 Volts For Specified Performance DD I Digital Inputs = 0 V or V DD DD Normal Operation 3.5 mA max Power-Down 1 A max V = 5 V DD Power Dissipation Normal Operation 17.5 mW max V = 5 V DD Power-Down 5 W max Auto Power-Down V = 3 V DD 1 kSPS Throughput 34.6 W max 10 kSPS Throughput 346.5 W max 100 kSPS Throughput 3.46 mW max NOTES 1 See Terminology section. 2 Sample tested during initial release and after any redesign or process change that may affect this parameter. Specifications subject to change without notice. REV. C 2