AD7862ARZ-2 Analog Devices Inc, AD7862ARZ-2 Datasheet

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AD7862ARZ-2

Manufacturer Part Number
AD7862ARZ-2
Description
DUAL 12-BIT PARALLEL ADC I.C.
Manufacturer
Analog Devices Inc
Datasheet

Specifications of AD7862ARZ-2

Number Of Bits
12
Sampling Rate (per Second)
250k
Data Interface
Parallel
Number Of Converters
2
Power Dissipation (max)
75mW
Voltage Supply Source
Analog and Digital
Operating Temperature
-40°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
28-SOIC (0.300", 7.50mm Width)
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
a
GENERAL DESCRIPTION
The AD7862 is a high speed, low power, dual 12-bit A/D
converter that operates from a single +5 V supply. The part
contains two 4 s successive approximation ADCs, two track/
hold amplifiers, an internal +2.5 V reference and a high speed
parallel interface. There are four analog inputs that are grouped
into two channels (A & B) selected by the A0 input. Each
channel has two inputs (V
sampled and converted simultaneously thus preserving the
relative phase information of the signals on both analog inputs.
The part accepts an analog input range of 10 V (AD7862-10),
protection on the analog inputs for the part allows the input
voltage to go to 17 V, 7 V or +7 V, respectively, without
causing damage.
A single conversion start signal (CONVST) places both track/
holds into hold simultaneously and initiates conversion on both
inputs. The BUSY signal indicates the end of conversion, and
at this time the conversion results for both channels are avail-
able to be read. The first read after a conversion accesses the
result from V
from V
A0 is low or high, respectively. Data is read from the part via a
12-bit parallel data bus with standard CS and RD signals.
In addition to the traditional dc accuracy specifications such as
linearity, full-scale and offset errors, the part is also specified for
dynamic performance parameters including harmonic distortion
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
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
2.5 V (AD7862-3) and 0–2.5 V (AD7862-2). Overvoltage
FEATURES
Two Fast 12-Bit ADCs
Four Input Channels
Simultaneous Sampling & Conversion
4 s Throughput Time
Single Supply Operation
Selection of Input Ranges:
High Speed Parallel Interface
Low Power, 60 mW typ
Power Saving Mode, 50 W typ
Overvoltage Protection on Analog Inputs
14-Bit Pin Compatible Upgrade (AD7863)
APPLICATIONS
AC Motor Control
Uninterrupted Power Supplies
Data Acquisition Systems
Communications
0 V to 2.5 V for AD7862-2
10 V for AD7862-10
2.5 V for AD7862-3
A2
or V
A1
B2
or V
, depending on whether the multiplexer select
B1
, while the second read accesses the result
A1
& V
A2
or V
B1
& V
B2
) that can be
The AD7862 is fabricated in Analog Devices’ Linear Compat-
ible CMOS (LC
that combines precision bipolar circuits with low power CMOS
logic. It is available in 28-lead SSOP, SOIC and DIP.
PRODUCT HIGHLIGHTS
1. The AD7862 features two complete ADC functions allowing
2. The AD7862 operates from a single +5 V supply and
3. The part offers a high speed parallel interface for easy con-
4. The part is offered in three versions with different analog
5. The part features very tight aperture delay matching between
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700
Fax: 617/326-8703
V
V
V
V
A1
B1
A2
B2
simultaneous sampling and conversion of two channels. Each
ADC has a 2-channel input mux. The conversion result for
both channels is available 3.6 s after initiating conversion.
consumes 60 mW typ. The automatic power-down mode,
where the part goes into power down once conversion is
complete and “wakes up” before the next conversion cycle,
makes the AD7862 ideal for battery-powered or portable
applications.
nection to microprocessors, microcontrollers and digital
signal processors.
input ranges. The AD7862-10 offers the standard industrial
input range of 10 V; the AD7862-3 offers the common
signal processing input range of 2.5 V; while the AD7862-2
can be used in unipolar 0 V – +2.5 V applications.
the two input sample-and-hold amplifiers.
SCALING
SCALING
SCALING
SCALING
SIGNAL
SIGNAL
SIGNAL
SIGNAL
Dual 250 kSPS 12-Bit ADC
V
FUNCTIONAL BLOCK DIAGRAM
A0
REF
CONTROL LOGIC
CONVERSION
2
Simultaneous Sampling
2k
MUX
MUX
MOS) process, a mixed technology process
BUSY
World Wide Web Site: http://www.analog.com
REFERENCE
CONVST
+2.5V
TRACK/
TRACK/
HOLD
HOLD
12-BIT
12-BIT
V
ADC
ADC
DD
AGND
© Analog Devices, Inc., 1996
CLOCK
AGND
AD7862
AD7862
OUTPUT
LATCH
DGND
DB0
DB11
CS
RD

Related parts for AD7862ARZ-2

AD7862ARZ-2 Summary of contents

Page 1

FEATURES Two Fast 12-Bit ADCs Four Input Channels Simultaneous Sampling & Conversion 4 s Throughput Time Single Supply Operation Selection of Input Ranges for AD7862-10 2.5 V for AD7862 2.5 V for AD7862-2 High ...

Page 2

AD7862–SPECIFICATIONS Parameter SAMPLE AND HOLD –3 dB Small Signal Bandwidth Aperture Delay Aperture Jitter Aperture Delay Matching 2 DYNAMIC PERFORMANCE 3 Signal to (Noise+Distortion) Ratio @ + MIN MAX 3 Total Harmonic Distortion 3 Peak Harmonic ...

Page 3

Parameter LOGIC OUTPUTS Output High Voltage Output Low Voltage DB11–DB0 Floating-State Leakage Current 4 Floating-State Capacitance Output Coding AD7862-10, AD7862-3 AD7863-2 CONVERSION RATE Conversion Time 2, 3 Track/Hold Acquisition Time POWER REQUIREMENTS ...

Page 4

AD7862 TIMING CHARACTERISTICS A, B Parameter Versions t 3.6 CONV t 0.3 ACQ Parallel Interface ...

Page 5

Pin Mnemonic Description Connect 2 DB11 Data Bit 11 (MSB). Three-state TTL output. Output coding is twos complement for the AD7862- 10 and AD7862-3. Output coding is straight (natural) binary for the AD7862-2. 3–6 DB10–DB7 Data Bit ...

Page 6

AD7862 TERMINOLOGY Signal to (Noise + Distortion) Ratio This is the measured ratio of signal to (noise + distortion) at the output of the A/D converter. The signal is the rms amplitude of the fundamental. Noise is the rms sum ...

Page 7

CONVERTER DETAILS The AD7862 is a high speed, low power, dual 12-bit A/D converter that operates from a single +5 V supply. The part contains two 4 s successive approximation ADCs, two track/ hold amplifiers, an internal +2.5 V reference ...

Page 8

AD7862 currents, as the resistor stage is followed by a high input impedance stage of the track/hold amplifier. For the AD7862-10 7 and For the AD7862-3, ...

Page 9

CONVST t 3 BUSY t CONV DATA Figure 5a. Mode 1 Timing Operation Diagram for High Sampling Performance and fourth read pulses, after the second conversion and A0 high, access the result from Channel B (V and ...

Page 10

AD7862 respectively). The third and fourth read pulses, after the second conversion and A0 high, access the result from Channel B (V and V respectively). Data is read from the part via a 12-bit B2 parallel data bus with standard ...

Page 11

Figure 7 shows a histogram plot for 8192 conversions input using the AD7862 with 5 V supply. The analog input was set at the center of a code transition. It can be seen that all the codes ...

Page 12

AD7862 Intermodulation Distortion With inputs consisting of sine waves at two frequencies, fa and fb, any active device with nonlinearities will create distortion products at sum and difference frequencies of mfa ...

Page 13

MICROPROCESSOR INTERFACING The AD7862 high speed bus timing allows direct interfacing to DSP processors as well as modern 16-bit microprocessors. Suitable microprocessor interfaces are shown in Figures 14 through 18. AD7862–ADSP-2100 Interface Figure 14 shows an interface between the AD7862 ...

Page 14

AD7862 Some applications may require that the conversion be initiated by the microprocessor rather than an external timer. One option is to decode the AD7862 CONVST from the address bus so that a write operation starts a conversion. Data is ...

Page 15

DSP MICROPROCESSOR DAC TORQUE & FLUX CONTROL LOOP CALCULATIONS & DAC TWO TO THREE PHASE INFORMATION DAC TORQUE SETPOINT FLUX SETPOINT V TRANSFORMATION TO TORQUE & FLUX CURRENT V A2 COMPONENTS AD7862 *ADDITIONAL PINS OMITTED FOR ...

Page 16

AD7862 28-Pin Plastic DIP (N-28) 1.565 (39.70) 1.380 (35.10 0.580 (14.73) 0.485 (12.32 PIN 1 0.060 (1.52) 0.250 0.015 (0.38) (6.35) MAX 0.150 (3.81) MIN 0.200 (5.05) 0.022 (0.558) 0.100 0.070 SEATING 0.125 (3.18) (1.77) (2.54) ...

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