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Details, datasheet, quote on part number:AD7918BRU
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Datasheet text preview:
8-Channel, 1 MSPS, 8-/10-/12-Bit ADCs with Sequencer in 20-Lead TSSOP AD7908/AD7918/AD7928
FEATURES Fast Throughput Rate: 1 MSPS Specified for AVDD of 2.7 V to 5.25 V Low Power: 6.0 mW Max at 1 MSPS with 3 V Supply 13.5 mW Max at 1 MSPS with 5 V Supply 8 (Single-Ended) Inputs with Sequencer Wide Input Bandwidth: AD7928, 70 dB Min SINAD at 50 kHz Input Frequency Flexible Power/Serial Clock Speed Management No Pipeline Delays High Speed Serial Interface SPITM/QSPITM/ MICROWIRETM/DSP Compatible Shutdown Mode: 0.5 A Max 20-Lead TSSOP Package FUNCTIONAL BLOCK DIAGRAM
AVDD REFIN VIN0 · · · · · · · · · · · · · VIN7
T/H 8-/10-/12-BIT SUCCESSIVE APPROXIMATION ADC I/P MUX
SCLK DOUT SEQUENCER CONTROL LOGIC DIN CS
GENERAL DESCRIPTION
The AD7908/AD7918/AD7928 are respectively, 8-bit, 10-bit, and 12-bit, high speed, low power, 8-channel, successive approximation ADCs. The parts operate from a single 2.7 V to 5.25 V power supply and feature throughput rates up to 1 MSPS. The parts contain a low noise, wide bandwidth trackand-hold amplifier that can handle input frequencies in excess of 8 MHz. The conversion process and data acquisition are controlled using CS and the serial clock signal, allowing the device to easily interface with microprocessors or DSPs. The input signal is sampled on the falling edge of CS and conversion is also initiated at this point. There are no pipeline delays associated with the part. The AD7908/AD7918/AD7928 use advanced design techniques to achieve very low power dissipation at maximum throughput rates. At maximum throughput rates, the AD7908/AD7918/AD7928 consume 2 mA maximum with 3 V supplies; with 5 V supplies, the current consumption is 2.7 mA maximum. Through the configuration of the Control Register, the analog input range for the part can be selected as 0 V to REFIN or 0 V to 2 × REFIN, with either straight binary or twos complement output coding. The AD7908/AD7918/AD7928 each feature eight single-ended analog inputs with a channel sequencer to allow a preprogrammed selection of channels to be converted sequentially. The conversion time for the AD7908/AD7918/AD7928 is determined by the SCLK frequency, as this is also used as the master clock to control the conversion.
AD7908/ AD7918/ AD7928
VDRIVE GND
PRODUCT HIGHLIGHTS
1. High Throughput with Low Power Consumption. The AD7908/AD7918/AD7928 offer up to 1 MSPS throughput rates. At the maximum throughput rate with 3 V supplies, the AD7908/AD7918/AD7928 dissipate just 6 mW of power maximum. 2. Eight Single-Ended Inputs with a Channel Sequencer. A sequence of channels can be selected, through which the ADC will cycle and convert on. 3. Single-Supply Operation with VDRIVE Function. The AD7908/AD7918/AD7928 operate from a single 2.7 V to 5.25 V supply. The VDRIVE function allows the serial interface to connect directly to either 3 V or 5 V processor systems independent of AVDD. 4. Flexible Power/Serial Clock Speed Management. The conversion rate is determined by the serial clock, allowing the conversion time to be reduced through the serial clock speed increase. The parts also feature various shutdown modes to maximize power efficiency at lower throughput rates. Current consumption is 0.5 µA max when in full shutdown. 5. No Pipeline Delay. The parts feature a standard successive approximation ADC with accurate control of the sampling instant via a CS input and once off conversion control.
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AD7908/AD7918/AD7928
= 2.7 AD7908SPECIFICATIONS (oAtVherw=isVe noted.) V to 5.25 V, REF
DD DRIVE IN
= 2.5 V, fSCLK = 20 MHz, TA = TMIN to TMAX, unless
Parameter DYNAMIC PERFORMANCE Signal-to-(Noise + Distortion) (SINAD)2 Signal-to-Noise Ratio (SNR)2 Total Harmonic Distortion (THD)2 Peak Harmonic or Spurious Noise (SFDR)2 Intermodulation Distortion (IMD)2 Second Order Terms Third Order Terms Aperture Delay Aperture Jitter Channel-to-Channel Isolation2 Full Power Bandwidth DC ACCURACY2 Resolution Integral Nonlinearity Differential Nonlinearity 0 V to REFIN Input Range Offset Error Offset Error Match Gain Error Gain Error Match 0 V to 2 × REFIN Input Range Positive Gain Error Positive Gain Error Match Zero Code Error Zero Code Error Match Negative Gain Error Negative Gain Error Match ANALOG INPUT Input Voltage Ranges DC Leakage Current Input Capacitance REFERENCE INPUT REFIN Input Voltage DC Leakage Current REFIN Input Impedance LOGIC INPUTS Input High Voltage, VINH Input Low Voltage, VINL Input Current, IIN Input Capacitance, CIN3 LOGIC OUTPUTS Output High Voltage, VOH Output Low Voltage, VOL Floating-State Leakage Current Floating-State Output Capacitance3 Output Coding CONVERSION RATE Conversion Time Track-and-Hold Acquisition Time Throughput Rate
B Version1 49 49 66 64 90 90 10 50 85 8.2 1.6 8 ±0.2 ±0.2 ±0.5 ±0.05 ±0.2 ±0.05 ±0.2 ±0.05 ±0.5 ±0.1 ±0.2 ±0.05 0 to REFIN 0 to 2 × REFIN ±1 20 2.5 ±1 36 0 . 7 × V DRIVE 0 . 3 × V DRIVE ±1 10
Unit dB min dB min dB max dB max
Test Conditions/Comments fIN = 50 kHz Sine Wave, fSCLK = 20 MHz
fa = 40.1 kHz, fb = 41.5 kHz dB typ dB typ ns typ ps typ dB typ MHz typ MHz typ Bits LSB max LSB max LSB max LSB max LSB max LSB max LSB max LSB max LSB max LSB max LSB max LSB max V V µA max pF typ V µA max k typ V min V max µA max pF max REFIN to +REFIN Biased about REFIN with Twos Complement Output Coding
fIN = 400 kHz @ 3 dB @ 0.1 dB
Guaranteed No Missed Codes to 8 Bits Straight Binary Output Coding
RANGE Bit Set to 1 RANGE Bit Set to 0, AVDD/VDRIVE = 4.75 V to 5.25 V
±1% Specified Performance fSAMPLE = 1 MSPS
Typically 10 nA, VIN = 0 V or VDRIVE
VDRIVE 0.2 V min 0.4 V max ±1 µA max 10 pF max Straight (Natural) Binary Twos Complement 800 300 300 1 ns max ns max ns max MSPS max 2
ISOURCE = 200 µA, AVDD = 2.7 V to 5.25 V ISINK = 200 µA Coding Bit Set to 1 Coding Bit Set to 0 16 SCLK Cycles with SCLK at 20 MHz Sine Wave Input Full-Scale Step Input See Serial Interface Section REV. 0
AD7908/AD7918/AD7928
Parameter POWER REQUIREMENTS A V DD V DRIVE IDD4 Normal Mode (Static) Normal Mode (Operational) Using Auto Shutdown Mode Full Shutdown Mode Power Dissipation4 Normal Mode (Operational) Auto Shutdown Mode (Static) Full Shutdown Mode
NOTES 1 Temperature ranges as follows: B Version: 40°C to +85°C. 2 See Terminology section. 3 Sample tested @ 25°C to ensure compliance. 4 See Power vs. Throughput Rate section. Specifications subject to change without notice.
B Version1 2.7/5.25 2.7/5.25 600 2.7 2 960 0.5 0.5 13.5 6 2.5 1.5 2.5 1.5
Unit V min/max V min/max µA typ mA max mA max µA typ µA max µA max mW max mW max µW max µW max µW max µW max
Test Conditions/Comments
Digital I/Ps = 0 V or VDRIVE AVDD = 2.7 V to 5.25 V, SCLK On or Off AVDD = 4.75 V to 5.25 V, fSCLK = 20 MHz AVDD = 2.7 V to 3.6 V, fSCLK = 20 MHz fSAMPLE = 250 kSPS (Static) SCLK On or Off (20 nA typ) AVDD = 5 V, fSCLK = 20 MHz AVDD = 3 V, fSCLK = 20 MHz A VD D = 5 V A VDD = 3 V A VDD = 5 V A VDD = 3 V
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3
AD7908/AD7918/AD7928
AD7918SPECIFICATIONS
Parameter DYNAMIC PERFORMANCE Signal-to-(Noise + Distortion) (SINAD)2 Signal-to-Noise Ratio (SNR)2 Total Harmonic Distortion (THD)2 Peak Harmonic or Spurious Noise (SFDR)2 Intermodulation Distortion (IMD)2 Second Order Terms Third Order Terms Aperture Delay Aperture Jitter Channel-to-Channel Isolation2 Full Power Bandwidth DC ACCURACY2 Resolution Integral Nonlinearity Differential Nonlinearity 0 V to REFIN Input Range Offset Error Offset Error Match Gain Error Gain Error Match 0 V to 2 × REFIN Input Range Positive Gain Error Positive Gain Error Match Zero Code Error Zero Code Error Match Negative Gain Error Negative Gain Error Match ANALOG INPUT Input Voltage Ranges DC Leakage Current Input Capacitance REFERENCE INPUT REFIN Input Voltage DC Leakage Current REFIN Input Impedance LOGIC INPUTS Input High Voltage, VINH Input Low Voltage, VINL Input Current, IIN Input Capacitance, CIN3 LOGIC OUTPUTS Output High Voltage, VOH Output Low Voltage, VOL Floating-State Leakage Current Floating-State Output Capacitance3 Output Coding CONVERSION RATE Conversion Time Track-and-Hold Acquisition Time Throughput Rate
(AVDD = VDRIVE = 2.7 V to 5.25 V, REFIN = 2.5 V, fSCLK = 20 MHz, TA = TMIN to TMAX, unless otherwise noted.)
Unit dB min dB min dB max dB max fa = 40.1 kHz, fb = 41.5 kHz dB typ dB typ ns typ ps typ dB typ MHz typ MHz typ Bits LSB max LSB max LSB max LSB max LSB max LSB max LSB max LSB max LSB max LSB max LSB max LSB max V V µA max pF typ V µA max k typ V min V max µA max pF max REFIN to +REFIN Biased about REFIN with Twos Complement Output Coding Test Conditions/Comments fIN = 50 kHz Sine Wave, fSCLK = 20 MHz
B Version1 61 61 72 74 90 90 10 50 85 8.2 1.6 10 ±0.5 ±0.5 ±2 ±0.2 ±0.5 ±0.2 ±0.5 ±0.2 ±2 ±0.2 ±0.5 ±0.2 0 to REFIN 0 to 2 × REFIN ±1 20 2.5 ±1 36 0 . 7 × V DRIVE 0 . 3 × V DRIVE ±1 10
fIN = 400 kHz @ 3 dB @ 0.1 dB
Guaranteed No Missed Codes to 10 Bits Straight Binary Output Coding
RANGE Bit Set to 1 RANGE Bit Set to 0, AVDD/VDRIVE = 4.75 V to 5.25 V
±1% Specified Performance fSAMPLE = 1 MSPS
Typically 10 nA, VIN = 0 V or VDRIVE
VDRIVE 0.2 V min 0.4 V max ±1 µA max 10 pF max Straight (Natural) Binary Twos Complement 800 300 300 1 4 ns max ns max ns max MSPS max
ISOURCE = 200 µA, AVDD = 2.7 V to 5.25 V ISINK = 200 µA Coding Bit Set to 1 Coding Bit Set to 0 16 SCLK Cycles with SCLK at 20 MHz Sine Wave Input Full-Scale Step Input See Serial Interface Section REV. 0
AD7908/AD7918/AD7928
Parameter POWER REQUIREMENTS A V DD V DRIVE IDD4 Normal Mode (Static) Normal Mode (Operational) Using Auto Shutdown Mode Full Shutdown Mode Power Dissipation4 Normal Mode (Operational) Auto Shutdown Mode (Static) Full Shutdown Mode
NOTES 1 Temperature ranges as follows: B Version: 40°C to +85°C. 2 See Terminology section. 3 Sample tested @ 25°C to ensure compliance. 4 See Power vs. Throughput Rate section. Specifications subject to change without notice.
B Version1 2.7/5.25 2.7/5.25 600 2.7 2 960 0.5 0.5 13.5 6 2.5 1.5 2.5 1.5
Unit V min/max V min/max µA typ mA max mA max µA typ µA max µA max mW max mW max µW max µW max µW max µW max
Test Conditions/Comments
Digital I/Ps = 0 V or VDRIVE AVDD = 2.7 V to 5.25 V, SCLK On or Off AVDD = 4.75 V to 5.25 V, fSCLK = 20 MHz AVDD = 2.7 V to 3.6 V, fSCLK = 20 MHz fSAMPLE = 250 kSPS (Static) SCLK On or Off (20 nA typ) AVDD = 5 V, fSCLK = 20 MHz AVDD = 3 V, fSCLK = 20 MHz A VD D = 5 V A VD D = 3 V A VDD = 5 V A VD D = 3 V
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