Datasheet AD7942 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | 14-Bit, 250 kSPS PulSAR , Pseudo Differential ADC in MSOP/LFCSP |
| Pages / Page | 25 / 1 — 14-Bit, 250 kSPS PulSAR,. Pseudo Differential ADC in MSOP/LFCSP. Data … |
| Revision | C |
| File Format / Size | PDF / 467 Kb |
| Document Language | English |
14-Bit, 250 kSPS PulSAR,. Pseudo Differential ADC in MSOP/LFCSP. Data Sheet. AD7942. FEATURES. APPLICATION DIAGRAM. 0.5V TO 5V
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14-Bit, 250 kSPS PulSAR, Pseudo Differential ADC in MSOP/LFCSP Data Sheet AD7942 FEATURES APPLICATION DIAGRAM 0.5V TO 5V 2.5V TO 5V 14-bit resolution with no missing codes Throughput: 250 kSPS INL: ±0.4 LSB typical, ±1 LSB maximum (±0.0061% of FSR) SINAD: 85 dB at 20 kHz REF VDD VIO 1.8V TO VDD 0V TO V THD: −100 dB at 20 kHz REF SDI IN+ AD7942 SCK Pseudo differential analog input range 3- OR 4-WIRE INTERFACE IN– SDO (SPI, DAISY CHAIN, CS) 0 V to VREF with VREF up to VDD GND CNV No pipeline delay
01
Single-supply 2.3 V to 5.5 V operation with
0 7- 65
1.8 V/2.5 V/3 V/5 V logic interface
04 Figure 1.
Proprietary serial interface SPI-/QSPI-/MICROWIRE-/DSP-compatible1 GENERAL DESCRIPTION Daisy-chaining for multiple ADCs and busy indicator
The AD7942 is a 14-bit, charge redistribution, successive approxi-
Power dissipation
mation PulSAR® ADC that operates from a single power supply,
1.25 mW at 2.5 V/100 kSPS, 3.6 mW at 5 V/100 kSPS
VDD, between 2.3 V to 5.5 V. It contains a low power, high
1.25 μW at 2.5 V/100 SPS
speed, 14-bit sampling ADC with no missing codes, an internal
Standby current: 1 nA
conversion clock, and a versatile serial interface port. The part
10-lead package: MSOP and 3 mm × 3 mm LFCSP
also contains a low noise, wide bandwidth, short aperture delay
Pin-for-pin compatible with the 16-bit AD7685
track-and-hold circuit. On the CNV rising edge, it samples an
APPLICATIONS
analog input, IN+, between 0 V to VREF with respect to a ground
Battery-powered equipment
sense, IN−. The reference voltage, VREF, is applied externally and
Data acquisition
is set up to be the supply voltage. Its power scales linearly with
Instrumentation
the throughput.
Medical instruments
The SPI-compatible serial interface also features the ability,
Process controls
using the SDI input, to daisy-chain several ADCs on a single 3-wire bus and provides an optional busy indicator. It is com- patible with 1.8 V, 2.5 V, 3 V, or 5 V logic using a separate supply (VIO). The AD7942 is housed in a 10-lead MSOP or a 10-lead LFCSP package yet fits in the same size footprint as the 8-lead MSOP or SOT-23. Operation for the AD7942 is specified from −40°C to +85°C. 1 Protected by U.S. Patent 6,703,961.
Table 1. MSOP, LFCSP/SOT-23, 14-/16-/18-Bit ADCs Type 100 kSPS 250 kSPS 400 kSPS to 500 kSPS ≥1000 kSPS ADC Driver
14-Bit AD7940 AD79421 AD79461 16-Bit AD7680 AD76851 AD76861 AD79801 ADA4941-x AD7683 AD76871 AD76881 AD79831 ADA4841-x AD7684 AD7694 AD76931 18-Bit AD76911 AD76901 AD79821 ADA4941-x AD79841 ADA4841-x 1 Pin-for-pin compatible to the AD7942.
Rev. C Document Feedback 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 that may result from its use. Specifications subject to change without notice. No One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Tel: 781.329.4700 ©2005–2014 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. Technical Support www.analog.com
Document Outline Features Applications Application Diagram General Description Table of Contents Revision History Specifications Timing Specifications Timing Diagrams Absolute Maximum Ratings ESD Caution Pin Configuration and Function Descriptions Typical Performance Characteristics Terminology Theory of Operation Circuit Information Converter Operation Transfer Functions Typical Connection Diagram Analog Input Driver Amplifier Choice Voltage Reference Input Power Supply Supplying the ADC from the Reference Digital Interface /CS Mode 3-Wire Without Busy Indicator /CS Mode 3-Wire with Busy Indicator /CS Mode 4-Wire Without Busy Indicator /CS Mode 4-Wire with Busy Indicator Chain Mode Without Busy Indicator Chain Mode with Busy Indicator Application Hints Layout Evaluating the Performance of AD7942 Outline Dimensions Ordering Guide
14-Bit, 250 kSPS PulSAR, Pseudo Differential ADC in MSOP/LFCSP Data Sheet AD7942 FEATURES APPLICATION DIAGRAM 0.5V TO 5V 2.5V TO 5V 14-bit resolution with no missing codes Throughput: 250 kSPS INL: ±0.4 LSB typical, ±1 LSB maximum (±0.0061% of FSR) SINAD: 85 dB at 20 kHz REF VDD VIO 1.8V TO VDD 0V TO V THD: −100 dB at 20 kHz REF SDI IN+ AD7942 SCK Pseudo differential analog input range 3- OR 4-WIRE INTERFACE IN– SDO (SPI, DAISY CHAIN, CS) 0 V to VREF with VREF up to VDD GND CNV No pipeline delay
01
Single-supply 2.3 V to 5.5 V operation with
0 7- 65
1.8 V/2.5 V/3 V/5 V logic interface
04 Figure 1.
Proprietary serial interface SPI-/QSPI-/MICROWIRE-/DSP-compatible1 GENERAL DESCRIPTION Daisy-chaining for multiple ADCs and busy indicator
The AD7942 is a 14-bit, charge redistribution, successive approxi-
Power dissipation
mation PulSAR® ADC that operates from a single power supply,
1.25 mW at 2.5 V/100 kSPS, 3.6 mW at 5 V/100 kSPS
VDD, between 2.3 V to 5.5 V. It contains a low power, high
1.25 μW at 2.5 V/100 SPS
speed, 14-bit sampling ADC with no missing codes, an internal
Standby current: 1 nA
conversion clock, and a versatile serial interface port. The part
10-lead package: MSOP and 3 mm × 3 mm LFCSP
also contains a low noise, wide bandwidth, short aperture delay
Pin-for-pin compatible with the 16-bit AD7685
track-and-hold circuit. On the CNV rising edge, it samples an
APPLICATIONS
analog input, IN+, between 0 V to VREF with respect to a ground
Battery-powered equipment
sense, IN−. The reference voltage, VREF, is applied externally and
Data acquisition
is set up to be the supply voltage. Its power scales linearly with
Instrumentation
the throughput.
Medical instruments
The SPI-compatible serial interface also features the ability,
Process controls
using the SDI input, to daisy-chain several ADCs on a single 3-wire bus and provides an optional busy indicator. It is com- patible with 1.8 V, 2.5 V, 3 V, or 5 V logic using a separate supply (VIO). The AD7942 is housed in a 10-lead MSOP or a 10-lead LFCSP package yet fits in the same size footprint as the 8-lead MSOP or SOT-23. Operation for the AD7942 is specified from −40°C to +85°C. 1 Protected by U.S. Patent 6,703,961.
Table 1. MSOP, LFCSP/SOT-23, 14-/16-/18-Bit ADCs Type 100 kSPS 250 kSPS 400 kSPS to 500 kSPS ≥1000 kSPS ADC Driver
14-Bit AD7940 AD79421 AD79461 16-Bit AD7680 AD76851 AD76861 AD79801 ADA4941-x AD7683 AD76871 AD76881 AD79831 ADA4841-x AD7684 AD7694 AD76931 18-Bit AD76911 AD76901 AD79821 ADA4941-x AD79841 ADA4841-x 1 Pin-for-pin compatible to the AD7942.
Rev. C Document Feedback 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 that may result from its use. Specifications subject to change without notice. No One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Tel: 781.329.4700 ©2005–2014 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. Technical Support www.analog.com
Document Outline Features Applications Application Diagram General Description Table of Contents Revision History Specifications Timing Specifications Timing Diagrams Absolute Maximum Ratings ESD Caution Pin Configuration and Function Descriptions Typical Performance Characteristics Terminology Theory of Operation Circuit Information Converter Operation Transfer Functions Typical Connection Diagram Analog Input Driver Amplifier Choice Voltage Reference Input Power Supply Supplying the ADC from the Reference Digital Interface /CS Mode 3-Wire Without Busy Indicator /CS Mode 3-Wire with Busy Indicator /CS Mode 4-Wire Without Busy Indicator /CS Mode 4-Wire with Busy Indicator Chain Mode Without Busy Indicator Chain Mode with Busy Indicator Application Hints Layout Evaluating the Performance of AD7942 Outline Dimensions Ordering Guide
