AD7298 Datasheet, PDF (1/18 Pages) Analog Devices – 8-Channel, 1MSPS, 12-Bit SAR ADC with Temperature Sensor

Preliminary Technical Data
8-Channel, 1MSPS, 12-Bit SAR ADC
with Temperature Sensor
AD7298
FEATURES
12 bit SAR ADC
8 single-ended inputs
Channel sequencer functionality
Fast throughput of 1Msps
Analog Input Range 0 to 2.5V
12-bit temperature-to-digital converter
Temperature sensor accuracy of ±2°C typical
Temperature range: −40°C to +125°C
Specified for V_DD of 2.8 V to 3.6V
Logic Voltage V_DRIVE = 1.65V to 3.6V
Power-down current : <10 µA
Internal 2.5V Reference
Internal Power on Reset
High speed serial interface SPI™
20-lead LFCSP
GENERAL DESCRIPTION
The AD7298 is a 12-bit, high speed, low power, 8-channel,
successive approximation ADC with an internal temperature
sensor. The part operates from a single 3.3V power supply and
features throughput rates up to 1MSPS. The device contains a
low noise, wide bandwidth track-and-hold amplifier that can
handle input frequencies in excess of 70 MHz.
The AD7298 offers a programmable sequencer, which enables
the selection of a pre-programmable sequence of channels for
conversion. The device has an on-chip 2.5 V reference that can be
disabled to allow the use of an external reference.
The AD7298 includes a high accuracy band-gap temperature
sensor, which is monitored and digitized by the12-bit ADC to
give a resolution of 0.25°C. The device offers a 4-wire serial
interface compatible with SPI, and DSP interface standards.
The AD7298 uses advanced design techniques to achieve very
low power dissipation at high throughput rates. The part also
offers flexible power/throughput rate management options. The
part is offered in a 20 lead LFCSP package.
FUNCTIONAL BLOCK DIAGRAM
Figure 1.
PRODUCT HIGHLIGHTS
1. Ideally suited to monitoring system variables in a variety of
systems including telecommunications, process and
industrial control.
1. High Throughput rate of 1Msps per channel with Low
Power Consumption.
2. Eight Single-Ended Inputs with a Channel Sequencer.
A consecutive sequence of channels can be selected on
which the ADC cycles and converts.
3. Integrated temperature sensor with 0.25°C resolution.
Table 1. AD7298 and Related Products
Device Resolution Interface Features
AD7298 12-Bit
SPI
8 Channel ADC & Temp Sensor
AD7291 12-Bit
I²C
8 Channel ADC & Temp Sensor
Rev. PrA
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