AD7993 Analog Devices, AD7993 Datasheet
AD7993
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AD7993 Summary of contents
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... AD7992 for 8-channel and 2-channel equivalent devices, respectively. GENERAL DESCRIPTION The AD7993/AD7994 are 4-channel, 10- and 12-bit, low power, successive approximation ADCs with an I face. The parts operate from a single 2 5.5 V power supply and feature a 2 µs conversion time. The parts contain a 4-channel multiplexer and track-and-hold amplifier that can handle input frequencies MHz ...
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... Writing Two Bytes of Data to a Limit or Hysteresis Register ........................................................................................ 24 Reading Data from the AD7993/AD7994................................... 26 Alert/Busy Pin................................................................................. 27 SMBus Alert ................................................................................ 27 Busy .............................................................................................. 27 Placing the AD7993-1/AD7994-1 into High Speed Mode ... 27 The Address Select (AS) Pin ..................................................... 27 Modes of Operation ....................................................................... 28 Mode 1—Using the CONVST Pin ........................................... 28 Mode 2—Command Mode....................................................... 29 Mode 3—Automatic Cycle Interval Mode.............................. 30 Outline Dimensions ...
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... AD7993 SPECIFICATIONS Temperature range for B version is −40°C to +125°C. Unless otherwise noted, V all specifications apply for 400 kHz. For the AD7993-1, all specs apply for f SCL MIN MAX. Table 1. Parameter 1 DYNAMIC PERFORMANCE 2 Signal-to-Noise + Distortion (SINAD) 2 Total Harmonic Distortion (THD) ...
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... AD7993/AD7994 Parameter LOGIC INPUTS (CONVST) Input High Voltage, V INH Input Low Voltage, V INL Input Leakage Current Input Capacitance LOGIC OUTPUTS (OPEN-DRAIN) Output Low Voltage Floating-State Leakage Current 3 Floating-State Output Capacitance Output Coding CONVERSION RATE Conversion Time Throughput Rate ...
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... DD 0 max DD ± 1 µA max 10 pF max 0 min DD Rev Page AD7993/AD7994 = 2 5.5 V; REF = 2.5 V. For the AD7994- 3.4 MHz, unless otherwise noted. SCL Test Conditions/Comments kHz sine wave for f from 1.7 MHz to IN SCL 3.4 MHz kHz sine wave for f ...
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... AD7993/AD7994 Parameter LOGIC INPUTS (CONVST) Input High Voltage, V INH Input Low Voltage, V INL Input Leakage Current Input Capacitance LOGIC OUTPUTS (OPEN-DRAIN) Output Low Voltage Floating-State Leakage Current 3 Floating-State Output Capacitance Output Coding CONVERSION RATE Conversion Time Throughput Rate ...
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... Guaranteed by initial characterization. All values measured with input filtering enabled and tf measured between 0.3 V and 0 High speed mode timing specifications apply to the AD7993-1/AD7994-1 only. Standard and fast mode timing specifications apply to both the AD7993-0/AD7994-0 and the AD7993-1/AD7994-1. See Figure 2. Unless otherwise noted 2 5.5 V; REF DD Table 3 ...
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... A device must provide a data hold time for SDA in order to bridge the undefined region of the SCL falling edge. 2 For 3 V supplies, the maximum hold time with SCL SDA START CONDITION P = STOP CONDITION AD7993/AD7994 Limit MIN MAX Min Max Unit 300 0.1 C 300 160 ...
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... Exposure to absolute DD −0 maximum rating conditions for extended periods may affect −0 0.3 V device reliability ±10 mA −40°C to +125°C −65°C to +150° 150°C 150.4°C/W 27.6°C/W 240(+0/-5)°C 260(+0)°C 1.5 kV Rev Page AD7993/AD7994 ...
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... GND AD7993 AD7993-x Float AD7994-0 GND AD7994-0 V AD7994-1 GND AD7994-1 V AD7994-x Float the AS pin is left floating on any of the AD7993/AD7994 parts, the device address is 010 0000. AGND AGND 1 16 AGND SCL 2 15 AD7993/ AGND SDA 3 14 AD7994 ALERT/BUSY AGND 4 13 ...
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... The AD7993/AD7994 is tested using the CCIF standard where two input frequencies near the top end of the input bandwidth are used. In this case, the second-order terms are usually dis- ...
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... Figure 4. AD7994 Dynamic Performance with 5 V Supply and 2.5 V Reference, 121 kSPS, Mode 1 –10 –30 –50 –70 –90 –110 FREQUENCY (kHz) Figure 5. AD7993 Dynamic Performance with 5 V Supply and 2.5 V Reference, 121 kSPS, Mode 1 100 ...
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... SCL 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 100 4.2 4 Figure 15. AD7994 Average Supply Current vs Rev Page AD7993/AD7994 POSITIVE DNL NEGATIVE DNL 1.7 2.2 2.7 3.2 3.7 4.2 REFERENCE VOLTAGE (V) Mode 1, 121 kSPS –40°C +25°C +85°C 3.2 3.7 4.2 4.7 SUPPLY VOLTAGE (V) Figure 14. AD7994 Shutdown Current vs. Supply Voltage, –40°C, +25°C, and +85°C ...
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... AD7993/AD7994 2.0 TEMPERATURE = +85°C 1.8 TEMPERATURE = +25°C TEMPERATURE = –40°C 1.6 TEMPERATURE = +85°C TEMPERATURE = +25°C MODE 2 - 147kSPS 1.4 TEMPERATURE = –40°C 1.2 1.0 MODE 1 - 121kSPS 0.8 0.6 0.4 0.2 0 2.7 3.2 3.7 4.2 SUPPLY VOLTAGE (V) Figure 16. AD7994 Average Supply Current vs. Supply Voltage for Various Temperatures 12.0 11.8 11.6 11.4 11.2 11.0 10.8 10.6 10.4 4.7 5.2 Rev Page ENOB V DD ENOB SINAD V DD SINAD V ...
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... CIRCUIT INFORMATION The AD7993/AD7994 are low power, 10- and 12-bit, single- supply, 4-channel A/D converters, respectively. The parts can be operated from a 2 5.5 V supply. The AD7993/AD7994 provide the user with a 4-channel multiplexer, an on-chip track-and-hold, an A/D converter, an on-chip oscillator, internal data registers, and an I serial interface, all housed in a 16-lead TSSOP package that offers the user considerable space-saving advantages over alternative solutions ...
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... AS can also be tied to AGND or left floating, allowing the user to select up to five AD7993/AD7994 devices on the same serial bus. An external reference must be applied to the AD7993/AD7994. This reference can be in the range of 1 precision reference like the REF 19x family, AD780, ...
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... INPUT FREQUENCY (kHz) Figure 23. THD vs. Analog Input Frequency for Various Supply Voltages, F –40 –50 –60 –70 –80 –90 –100 10 INPUT FREQUENCY (kHz) Figure 24. THD vs. Analog Input Frequency for Various Source Impedances for V Rev Page AD7993/AD7994 ...
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... LSBs are used as pointer bits to store an address that points to one of the AD7993/AD7994’s data registers. The 4 MSBs are used as command bits when operating in Mode 2 (see the Modes of Operation section). The first byte following each write address ...
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... CONFIGURATION REGISTER The configuration register is an 8-bit read/write register that is used to set the operating modes of the AD7993/AD7994. The bit functions are outlined in Table 9. A single-byte write is necessary when writing to the configuration register. Table 9. Configuration Register Bit Function Descriptions and Default Settings at Power-Up ...
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... The conversion result of the AD7993/AD7994 consists of an Alert_Flag bit, a zero bit, two channel identifier bits, and the 10- and 12-bit data result. For the AD7993, the 2 LSB (D1 and D0) of the second read contain two trailing 0s. The Alert_Flag bit indicates whether the conversion result being read or any other channel result has violated the limit registers associated with it ...
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... Table 8. On power-up, the hysteresis registers contain a value of 8 LSB for the AD7994 and 2 LSB for the AD7993 different hysteresis value is required, that value must be written to the hysteresis register for the channel in question. For the AD7993, D1 and D0 of the hysteresis register should contain 0s ...
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... On power-up, the cycle timer register contains all 0s, thus disabling automatic cycle operation of the AD7993/AD7994. To enable automatic cycle mode, the user must write to the cycle timer register, selecting the required conversion interval. Table 24 shows the structure of the cycle timer register while Table 25 shows how the bits in this register are decoded to provide various automatic sampling intervals ...
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... SERIAL BUS ADDRESS 2 Like all I C-compatible devices, the AD7993/AD7994 have a 7-bit serial address. The 3 MSB of this address for the AD7993/ AD7994 are set to 010. The AD7993/AD7994 come in two versions, the AD7993-0/AD7994-0 and AD7993-1AD7994-1. 2 The two versions have three different I ...
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... See Figure 28. If the master is write addressing the AD7993/AD7994, it can write to more than one register. After the first write operation has completed for the first data register in the next byte, the master writes to the address pointer byte to select the next data register for a write operation ...
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... R ACK. BY AD7993/AD7994 FRAME 1 ADDRESS POINTER REGISTER D11 D10 ACK. BY AD7993/AD7994 LEAST SIGNIFICANT DATA BYTE Figure 28. Two-Byte Write Sequence Rev Page AD7993/AD7994 ACK. BY AD7993/AD7994 FRAME D1/0 D0/0 ACK. BY STOP BY AD7993/AD7994 MASTER ...
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... Figure 30. The same rules apply for a 2-byte read as a 1-byte read. When reading data back from a register on the AD7993 or the AD7994, for example the conversion result register, if more than two read bytes are supplied, the same or new data is read from the AD7993/AD7994 without the need to readdress the device ...
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... All devices continue to operate in high speed mode until the master issues a stop condition. When the stop condition is issued, the devices all return to fast mode. THE ADDRESS SELECT (AS) PIN The address select pin on the AD7993/AD7994 is used to set 2 the I can be tied to V should be made as close as possible to the AS pin; avoid having long tracks introducing extra capacitance on the pin ...
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... The cycle timer register and Bits the address pointer register should contain all 0s when operating the AD7994/ AD7993 in this mode. The CONVST pin should be tied low for all other modes of operation. To select an analog input channel for conversion in this mode, the user must write to the configuration register and select the corresponding channel for conversion ...
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... MHz SCL, the conversion may not be complete before the master tries to read the conversion result. If this is the case, the AD7994-1/AD7993-1 hold the SCL line low during the ACK clock after the read address until the con- version is complete. When the conversion is complete, the AD7994-1/AD7993-1 release the SCL line and the master can then read the conversion result ...
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... An automatic conversion cycle can be selected and enabled by writing a value to the cycle timer register. A conversion cycle interval can be set up on the AD7993/AD7994 by programming the relevant bits in the 8-bit cycle timer register, as decoded in Table 25. Only the 3 LSB are used; the 5 MSB should contain 0s. ...
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... LSB ±0.5 LSB ±1 LSB ±1 LSB ±1 LSB ±1 LSB ±1 LSB ±1 LSB ±1 LSB ±1 LSB 2 C interface modes. The AD7993-1/AD7994-1 support standard, fast, and high speed I Number of Input Channels Rev Page AD7993/AD7994 0.75 0.60 0.45 Package Option ...
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... AD7993/AD7994 NOTES 2 Purchase of licensed I C components of Analog Devices or one of its sublicensed Associated Companies conveys a license for the purchaser under the Philips I Rights to use these components system, provided that the system conforms to the I © 2004 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D03472– ...