PRELIMINARY TECHNICAL DATA
Differential Input, 1MSPS,
a
PreliminaryTechnicalData
12-Bit ADC in µSO-8 and S0-8
AD7450
FEATURES
F U NC T IO NAL B LO C K D IAG RAM
Fast Throughput Rate: 1MSPS
Specified for VDD of 3 V and 5 V
Low Pow er at m ax Throughput Rate:
3 m W typ at 833kSPS w ith 3 V Supplies
8 m W typ at 1MSPS w ith 5 V Supplies
Fully Differential Analog Input
Wide Input Bandw idth:
V
DD
V
V
12-BIT SUCCESSIVE
IN+
APPROXIMATION
ADC
T/H
70d B S INAD a t 300kHz In p u t Fre q u e n cy
Flexible Pow er/ Serial Clock Speed Managem ent
No Pipeline Delays
IN-
V
REF
Hig h S p e e d S e ria l In t e rfa ce - S PITM/ QS PITM
/
Micro Wire TM
/ DS P Co m p a t ib le
SCLK
SDATA
CS
Po w e rd o w n Mo d e : 1µA m a x
8 Pin µSOIC and SOIC Packages
CONTROL
LOGIC
AD7450
APPLICATIONS
Transducer Interface
Battery Pow ered System s
Data Acquisition System s
Portable Instrum entation
Motor Control
Com m unications
GND
G E NE R AL D E S C R IP T IO N
T he AD7450 is a 12-bit, high speed, low power, succes-
sive-approximation (SAR) analog-to-digital converter
featuring a fully differential analog input. It operates from
a single 3 V or 5 V power supply and features throughput
rates up to 833kSPS or 1MSPS respectively.
T he SAR architecture of this part ensures that there are
no pipeline delays.
T he AD7450 uses advanced design techniques to achieve
very low power dissipation at high throughput rates.
T his part contains a low-noise, wide bandwidth, differen-
tial track and hold amplifier (T /H) which can handle
input frequencies in excess of 1MHz with the -3dB point
being 20MHz typically. T he reference voltage for the
AD7450 is applied externally to the VREF pin and can be
varied from 100 mV to 2.5 V depending on the power
supply and to suit the application. T he value of the refer-
ence voltage determines the common mode voltage range
of the part. With this truly differential input structure and
variable reference input, the user can select a variety of
input ranges and bias points.
P R O D U C T H IG H LIG H T S
1.Operation with either 3 V or 5 V power supplies.
2.H igh T hroughput with Low Power Consumption.
With a 3V supply, the AD7450 offers 3mW typ power
consumption for 833kSPS throughput.
3.Fully D ifferential Analog Input.
4.Flexible Power/Serial C lock Speed M anagement.
T he conversion rate is determined by the serial clock,
allowing the power to be reduced as the conversion time
is reduced through the serial clock speed increase. T his
part also features a shutdown mode to maximize power
efficiency at lower throughput rates.
T he conversion process and data acquisition are controlled
using CS and the serial clock allowing the device to inter-
face with Microprocessors or DSPs. T he input signals are
sampled on the falling edge of CS and the conversion is
also initiated at this point.
5.Variable Voltage Reference Input.
6.N o Pipeline D elay.
7.Accurate control of the sampling instant via a CS input
and once off conversion control.
8. ENOB > 8 bits typ with 100mV Reference.
MicroWire is a trademark of National Semiconductor Corporation.
SPI and QSPI are trademarks of Motorola, Inc.
REV. PrJ 27/02/02
Inform ation furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assum ed by Analog Devices for its
use, nor for any infringem ents of patents or other rights of third parties
which m ay result from its use. No license is granted by im plication or
otherwise under any patent or patent rights of Analog Devices.
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