AD7782BRUZ-REEL

Manufacturer Part NumberAD7782BRUZ-REEL
Description2 Chnl Non-writeable 24-bit ADC
ManufacturerAnalog Devices Inc
AD7782BRUZ-REEL datasheet
 

Specifications of AD7782BRUZ-REEL

Number Of Bits24Sampling Rate (per Second)19.79
Data InterfaceDSP, MICROWIRE™, QSPI™, Serial, SPI™Number Of Converters1
Power Dissipation (max)3.9mWVoltage Supply SourceSingle Supply
Operating Temperature-40°C ~ 85°CMounting TypeSurface Mount
Package / Case16-TSSOP (0.173", 4.40mm Width)Lead Free Status / RoHS StatusLead free / RoHS Compliant
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GENERAL DESCRIPTION
The AD7782 is a complete analog front end for low-frequency
measurement applications. The 24-bit sigma-delta ADC contains
two fully differential analog input channels that can be config-
ured with a gain of 1 or 16 allowing full-scale input signal ranges
of ± 2.56 V or ± 160 mV from a +2.5 V differential reference
input.
The AD7782 has an extremely simple, read-only digital interface
which can be operated in master mode or slave mode. There are
no on-chip registers to be programmed. The input signal range
and input channel selection are configured using two external pins.
SPI and QSPI are trademarks of Motorola Inc.
MICROWIRE is a trademark of National Semiconductor Corporation.
Read Only, Pin Configured
24-Bit - ADC
FUNCTIONAL BLOCK DIAGRAM
V
GND
REFIN(+)
REFIN(–)
DD
AD7782
AIN1(+)
24-BIT -
AIN1(–)
MUX
BUF
PGA
ADC
AIN2(+)
AIN2(–)
CH1/CH2
RANGE
BASIC CONNECTION DIAGRAM
POWER SUPPLY
V
DD
AD7782
AIN1(+)
ANALOG
INPUT
AIN1(–)
DOUT/RDY
AIN2(+)
ANALOG
SCLK
INPUT
AIN2(–)
XTAL1
REFIN(+)
REFERENCE
XTAL2
INPUT
REFIN(–)
GND
The device operates from a 32.768 kHz crystal with an on-chip PLL
generating the required internal operating frequency. The output
data rate from the part is fixed via the master clock at 19.79 Hz and
provides simultaneous 50 Hz and 60 Hz rejection at this update
rate. Eighteen-bit p-p resolution can be obtained at this update rate.
The part operates from a single 3 V or 5 V supply. When operating
from 3 V supplies, the power dissipation for the part is 3.9 mW.
The AD7782 is available in a 16-lead TSSOP package.
Another part in the AD778x family is the AD7783. It is similar
to the AD7782 except it has two integrated current sources and
only one differential input channel.
AD7782
XTAL1 XTAL2
OSCILLATOR
AND
PLL
DOUT/RDY
SERIAL
INTERFACE
AND
SCLK
CONTROL
LOGIC
MODE
CS
CS
DIGITAL
INTERFACE
32.768kHz
CRYSTAL

AD7782BRUZ-REEL Summary of contents

  • Page 1

    GENERAL DESCRIPTION The AD7782 is a complete analog front end for low-frequency measurement applications. The 24-bit sigma-delta ADC contains two fully differential analog input channels that can be config- ured with a gain allowing full-scale ...

  • Page 2

    AD7782–SPECIFICATIONS Parameter ADC CHANNEL SPECIFICATION Output Update Rate ADC CHANNEL 2 No Missing Codes Resolution Output Noise Integral Nonlinearity Offset Error Offset Error Drift vs. Temperature Full-Scale Error Gain Drift vs. Temperature Power Supply Rejection (PSR) ANALOG INPUTS Differential Input ...

  • Page 3

    Parameter LOGIC INPUTS (continued) 2 XTAL1 Only V , Input Low Voltage INL V , Input High Voltage INH V , Input Low Voltage INL V , Input High Voltage INH Input Currents Input Capacitance LOGIC OUTPUTS (Excluding XTAL2) 2 ...

  • Page 4

    AD7782 TIMING CHARACTERISTICS Limit at T Parameter (B Version) t 30.5176 1 t 50.54 ADC × ADC ...

  • Page 5

    CH1/CH2 ( ( DOUT/RDY SLAVE MODE SCLK (I) t MASTER MODE SCLK ( INPUT TO AD7782 OUTPUT FROM AD7782 SLAVE MODE IS SELECTED BY TYING THE MODE PIN LOW, ...

  • Page 6

    AD7782 Pin No. Mnemonic Function 1 XTAL1 Input to the 32.768 kHz Crystal Oscillator Inverter. 2 REFIN(+) Positive Reference Input. REFIN(+) can lie anywhere between V voltage (REFIN(+) – REFIN(–)) is 2.5 V, but the part functions with a reference ...

  • Page 7

    Typical Performance Characteristics ADC CIRCUIT INFORMATION Overview The AD7782 incorporates an analog multiplexer with a Σ-∆ ADC channel, on-chip programmable gain amplifier, and on-chip digital filtering intended for the measurement ...

  • Page 8

    AD7782 NOISE PERFORMANCE Table I shows the output rms noise and output peak-to-peak resolution in bits (rounded to the nearest 0.5 LSB) for the two input voltage ranges. The numbers are typical and generated at a differential input voltage of ...

  • Page 9

    Bipolar Configuration/Output Coding The analog inputs on the AD7782 accept bipolar input voltage ranges. Signals on the AIN(+) input of the ADC are referenced to the voltage on the respective AIN(–) input. For example, if AIN(–) is 2.5 V and ...

  • Page 10

    AD7782 SEATING OUTLINE DIMENSIONS Dimensions shown in inches and (mm). 16-Lead Thin Shrink SO Plastic (TSSOP) (RU-16) 0.201 (5.10) 0.193 (4.90 0.177 (4.50) 0.169 (4.30) 0.256 (6.50) 0.246 (6.25 PIN 1 0.006 (0.15) 0.0433 (1.10) MAX ...

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