Datasheet AD7862 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | Simultaneous Sampling Dual 250 kSPS 12-Bit ADC |
| Pages / Page | 17 / 1 — Simultaneous Sampling. Dual 250 kSPS 12-Bit ADC. AD7862. FEATURES. … |
| File Format / Size | PDF / 454 Kb |
| Document Language | English |
Simultaneous Sampling. Dual 250 kSPS 12-Bit ADC. AD7862. FEATURES. FUNCTIONAL BLOCK DIAGRAM. Two Fast 12-Bit ADCs. VREF. VDD
Model Line for this Datasheet
Text Version of Document
Simultaneous Sampling
a
Dual 250 kSPS 12-Bit ADC AD7862 FEATURES FUNCTIONAL BLOCK DIAGRAM Two Fast 12-Bit ADCs VREF VDD Four Input Channels Simultaneous Sampling & Conversion +2.5V REFERENCE 2k 4
Ω m
s Throughput Time AD7862 Single Supply Operation Selection of Input Ranges:
6
10 V for AD7862-10 SIGNAL VA1 TRACK/ SCALING
6
2.5 V for AD7862-3 HOLD MUX 12-BIT SIGNAL 0 V to 2.5 V for AD7862-2 V ADC B1 DB0 SCALING High Speed Parallel Interface OUTPUT SIGNAL LATCH VA2 DB11 Low Power, 60 mW typ SCALING TRACK/ MUX HOLD Power Saving Mode, 50
m
W typ SIGNAL 12-BIT VB2 SCALING ADC Overvoltage Protection on Analog Inputs 14-Bit Pin Compatible Upgrade (AD7863) CS CONVERSION CLOCK RD CONTROL LOGIC APPLICATIONS AC Motor Control Uninterrupted Power Supplies A0 BUSY CONVST AGND AGND DGND Data Acquisition Systems Communications GENERAL DESCRIPTION
The AD7862 is fabricated in Analog Devices’ Linear Compat- The AD7862 is a high speed, low power, dual 12-bit A/D ible CMOS (LC2MOS) process, a mixed technology process converter that operates from a single +5 V supply. The part that combines precision bipolar circuits with low power CMOS contains two 4 µs successive approximation ADCs, two track/ logic. It is available in 28-lead SSOP, SOIC and DIP. hold amplifiers, an internal +2.5 V reference and a high speed parallel interface. There are four analog inputs that are grouped
PRODUCT HIGHLIGHTS
into two channels (A & B) selected by the A0 input. Each 1. The AD7862 features two complete ADC functions allowing channel has two inputs (V & V or V & V ) that can be simultaneous sampling and conversion of two channels. Each A1 A2 B1 B2 sampled and converted simultaneously thus preserving the ADC has a 2-channel input mux. The conversion result for relative phase information of the signals on both analog inputs. both channels is available 3.6 µs after initiating conversion. The part accepts an analog input range of ± 10 V (AD7862-10), ± 2. The AD7862 operates from a single +5 V supply and 2.5 V (AD7862-3) and 0–2.5 V (AD7862-2). Overvoltage consumes 60 mW typ. The automatic power-down mode, protection on the analog inputs for the part allows the input where the part goes into power down once conversion is voltage to go to ± 17 V, ± 7 V or +7 V, respectively, without complete and “wakes up” before the next conversion cycle, causing damage. makes the AD7862 ideal for battery-powered or portable A single conversion start signal (CONVST) places both track/ applications. holds into hold simultaneously and initiates conversion on both 3. The part offers a high speed parallel interface for easy con- inputs. The BUSY signal indicates the end of conversion, and nection to microprocessors, microcontrollers and digital at this time the conversion results for both channels are avail- signal processors. able to be read. The first read after a conversion accesses the result from V 4. The part is offered in three versions with different analog A1 or VB1, while the second read accesses the result from V input ranges. The AD7862-10 offers the standard industrial A2 or VB2, depending on whether the multiplexer select A0 is low or high, respectively. Data is read from the part via a input range of ± 10 V; the AD7862-3 offers the common 12-bit parallel data bus with standard CS and RD signals. signal processing input range of ±2.5 V; while the AD7862-2 can be used in unipolar 0 V – +2.5 V applications. In addition to the traditional dc accuracy specifications such as linearity, full-scale and offset errors, the part is also specified for 5. The part features very tight aperture delay matching between dynamic performance parameters including harmonic distortion the two input sample-and-hold amplifiers. and signal-to-noise ratio. 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
Tel: 617/329-4700 World Wide Web Site: http://www.analog.com
otherwise under any patent or patent rights of Analog Devices.
Fax: 617/326-8703 © Analog Devices, Inc., 1996
a
Dual 250 kSPS 12-Bit ADC AD7862 FEATURES FUNCTIONAL BLOCK DIAGRAM Two Fast 12-Bit ADCs VREF VDD Four Input Channels Simultaneous Sampling & Conversion +2.5V REFERENCE 2k 4
Ω m
s Throughput Time AD7862 Single Supply Operation Selection of Input Ranges:
6
10 V for AD7862-10 SIGNAL VA1 TRACK/ SCALING
6
2.5 V for AD7862-3 HOLD MUX 12-BIT SIGNAL 0 V to 2.5 V for AD7862-2 V ADC B1 DB0 SCALING High Speed Parallel Interface OUTPUT SIGNAL LATCH VA2 DB11 Low Power, 60 mW typ SCALING TRACK/ MUX HOLD Power Saving Mode, 50
m
W typ SIGNAL 12-BIT VB2 SCALING ADC Overvoltage Protection on Analog Inputs 14-Bit Pin Compatible Upgrade (AD7863) CS CONVERSION CLOCK RD CONTROL LOGIC APPLICATIONS AC Motor Control Uninterrupted Power Supplies A0 BUSY CONVST AGND AGND DGND Data Acquisition Systems Communications GENERAL DESCRIPTION
The AD7862 is fabricated in Analog Devices’ Linear Compat- The AD7862 is a high speed, low power, dual 12-bit A/D ible CMOS (LC2MOS) process, a mixed technology process converter that operates from a single +5 V supply. The part that combines precision bipolar circuits with low power CMOS contains two 4 µs successive approximation ADCs, two track/ logic. It is available in 28-lead SSOP, SOIC and DIP. hold amplifiers, an internal +2.5 V reference and a high speed parallel interface. There are four analog inputs that are grouped
PRODUCT HIGHLIGHTS
into two channels (A & B) selected by the A0 input. Each 1. The AD7862 features two complete ADC functions allowing channel has two inputs (V & V or V & V ) that can be simultaneous sampling and conversion of two channels. Each A1 A2 B1 B2 sampled and converted simultaneously thus preserving the ADC has a 2-channel input mux. The conversion result for relative phase information of the signals on both analog inputs. both channels is available 3.6 µs after initiating conversion. The part accepts an analog input range of ± 10 V (AD7862-10), ± 2. The AD7862 operates from a single +5 V supply and 2.5 V (AD7862-3) and 0–2.5 V (AD7862-2). Overvoltage consumes 60 mW typ. The automatic power-down mode, protection on the analog inputs for the part allows the input where the part goes into power down once conversion is voltage to go to ± 17 V, ± 7 V or +7 V, respectively, without complete and “wakes up” before the next conversion cycle, causing damage. makes the AD7862 ideal for battery-powered or portable A single conversion start signal (CONVST) places both track/ applications. holds into hold simultaneously and initiates conversion on both 3. The part offers a high speed parallel interface for easy con- inputs. The BUSY signal indicates the end of conversion, and nection to microprocessors, microcontrollers and digital at this time the conversion results for both channels are avail- signal processors. able to be read. The first read after a conversion accesses the result from V 4. The part is offered in three versions with different analog A1 or VB1, while the second read accesses the result from V input ranges. The AD7862-10 offers the standard industrial A2 or VB2, depending on whether the multiplexer select A0 is low or high, respectively. Data is read from the part via a input range of ± 10 V; the AD7862-3 offers the common 12-bit parallel data bus with standard CS and RD signals. signal processing input range of ±2.5 V; while the AD7862-2 can be used in unipolar 0 V – +2.5 V applications. In addition to the traditional dc accuracy specifications such as linearity, full-scale and offset errors, the part is also specified for 5. The part features very tight aperture delay matching between dynamic performance parameters including harmonic distortion the two input sample-and-hold amplifiers. and signal-to-noise ratio. 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
Tel: 617/329-4700 World Wide Web Site: http://www.analog.com
otherwise under any patent or patent rights of Analog Devices.
Fax: 617/326-8703 © Analog Devices, Inc., 1996
