ADS8284_14 Datasheet, PDF (1/46 Pages) Texas Instruments – ADS8284 18-BIT, 1-MSPS, Pseudo-Bipolar Differential SAR ADC with On-Chip ADC Driver (OPA) and 4-Channel Differential Multiplexer

Not Recommended for New Designs
ADS8284
SLAS628A – MARCH 2009 – REVISED APRIL 2014
ADS8284 18-BIT, 1-MSPS, Pseudo-Bipolar Differential SAR ADC with On-Chip ADC Driver
(OPA) and 4-Channel Differential Multiplexer
1 Features
•1 1.0-MHz Sample Rate, Zero Latency at Full
Speed
• 18-Bit Resolution
• Supports Pseudo-Bipolar Differential Input Range:
-4 V to +4 V with 2-V Common-Mode
• Built-In Four Channel, Differential Ended
Multiplexer; with Channel Count Selection and
Auto/Manual Mode
• On-Board Differential ADC Driver (OPA)
• Buffered Reference Output to Level Shift Bipolar
±4-V Input with External Resistance Divider
• Reference/2 Output to Set Common-Mode for
External Signal Conditioner
• 18-/16-/8-Bit Parallel Interface
• SNR: 98.4dB Typ at 2-kHz I/P
• THD: –119dB Typ at 2-kHz I/P
• Power Dissipation: 331.25 mW at 1 MSPS
Including ADC Driver
• Internal Reference
• Internal Reference Buffer
• 64-Pin QFN Package
2 Applications
• Medical Imaging/CT Scanners
• Automated Test Equipment
• High-Speed Data Acquisition Systems
• High-Speed Closed-Loop Systems
3 Description
The ADS8284 is a high-performance analog system-
on-chip (SoC) device with an 18-bit, 1-MSPS A/D
converter, 4-V internal reference, an on-chip ADC
driver (OPA), and a 4-channel differential multiplexer.
The channel count of the multiplexer and auto/manual
scan modes of the device are user selectable.
The ADC driver is designed to leverage the very high
noise performance of the differential ADC at optimum
power usage levels.
The ADS8284 outputs a buffered reference signal for
level shifting of a ±4-V bipolar signal with an external
resistance divider. A V_ref/2 output signal is available
to set the common-mode of a signal conditioning
circuit. The device also includes an 18-/16-/8-bit
parallel interface.
The ADS8284 is available in a 9 mm x 9 mm, 64-pin
QFN package and is characterized from -40°C to
85°C.
Device Information ⁽¹⁾
DEVICE NAME
PACKAGE
BODY SIZE
ADS8284
QFN (64)
9mm x 9mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Simplified Schematic
Analog 5 V
0.1 µF
AGND
10 µF
0.1 µF
Ext Ref Input
Analog Input
Micro
Controller
GPIO
GPIO
GPIO
GPIO
RD
AD[7:0]
Data Bus D[17:0]
CS
BYTE
AD8284
BUS18/16
CONVST
RD
DB[17:10]
BDGND
+VBD
Digital 3 V
0.1 µF
BDGND
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.