AD7490 Datasheet, PDF (1/24 Pages) Analog Devices – 16-Channel, 1 MSPS, 12-Bit ADC with Sequencer in 28-Lead TSSOP

a
16-Channel, 1 MSPS, 12-Bit ADC
with Sequencer in 28-Lead TSSOP
AD7490
FEATURES
Fast Throughput Rate: 1 MSPS
Specified for V_DD of 2.7 V to 5.25 V
Low Power at Max Throughput Rates:
5.4 mW Max at 870 kSPS with 3 V Supplies
12.5 mW Max at 1 MSPS with 5 V Supplies
16 (Single-Ended) Inputs with Sequencer
Wide Input Bandwidth:
69.5 dB SNR at 50 kHz Input Frequency
Flexible Power/Serial Clock Speed Management
No Pipeline Delays
High Speed Serial Interface SPI™/QSPI™/
MICROWIRE™/DSP Compatible
Full Shutdown Mode: 0.5 ␮A Max
28-Lead TSSOP and 32-Lead LFCSP Packages
GENERAL DESCRIPTION
The AD7490 is a 12-bit high speed, low power, 16-channel,
successive-approximation ADC. The part operates from a single
2.7 V to 5.25 V power supply and features throughput rates up
to 1 MSPS. The part contains a low noise, wide bandwidth
track-and-hold amplifier that can handle input frequencies in
excess of 1 MHz.
The conversion process and data acquisition are controlled
using CS and the serial clock signal, allowing the device to
easily interface with microprocessors or DSPs. The input signal
is sampled on the falling edge of CS and conversion is also
initiated at this point. There are no pipeline delays associated
with the part.
The AD7490 uses advanced design techniques to achieve very
low power dissipation at high throughput rates. For maximum
throughput rates, the AD7490 consumes just 1.8 mA with 3 V
supplies, and 2.5 mA with 5 V supplies.
By setting the relevant bits in the Control Register, the analog
input range for the part can be selected to be a 0 to REF_IN input or
a 0 to 2 Ï« REF_IN with either straight binary or twos complement
output coding. The AD7490 features 16 single-ended analog
inputs with a channel sequencer to allow a preprogrammed
selection of channels to be converted sequentially.
The conversion time is determined by the SCLK frequency as
this is also used as the master clock to control the conversion.
The AD7490 is available in a 28-lead thin shrink small outline
(TSSOP) package, and a 32-lead chip scale package.
SPI and QSPI are trademarks of Motorola Inc.
MICROWIRE is a trademark of National Semiconductor Corporation
REV. A
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 that
may result from its use. No license is granted by implication or otherwise
under any patent or patent rights of Analog Devices.
REF_IN
V_IN0
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V_IN15
FUNCTIONAL BLOCK DIAGRAM
V_DD
T/H
I/P
MUX
12-BIT
SUCCESSIVE
APPROXIMATION
ADC
SEQUENCER
CONTROL LOGIC
AD7490
GND
SCLK
DOUT
DIN
CS
V_DRIVE
PRODUCT HIGHLIGHTS
1. High Throughput with Low Power Consumption
The AD7490 offers up to 1 MSPS throughput rates. At
maximum throughput with 3 V supplies, the AD7490
dissipates just 5.4 mW of power.
2. Sixteen Single-Ended Inputs with Channel Sequencer
A Sequence of channels can be selected, through which the
AD7490 will cycle and convert.
3. Single-Supply Operation with V_DRIVE Function
The AD7490 operates from a single 2.7 V to 5.25 V supply.
The V_DRIVE function allows the serial interface to connect
directly to either 3 V or 5 V processor systems independent
of V_DD.
4. Flexible Power/Serial Clock Speed Management
The conversion rate is determined by the serial clock, allowing
the conversion time to be reduced through the serial clock
speed increase. The part also features various shutdown
modes to maximize power efficiency at lower throughput
rates. Power consumption is 0.5 µA max when in full shutdown.
5. No Pipeline Delay
The part features a standard successive-approximation ADC
with accurate control of the sampling instant via a CS input
and once off conversion control.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone]
www.analog.com
Fax: [phone]
© Analog Devices, Inc., 2002