ADS8885_14 Datasheet, PDF (1/49 Pages) Texas Instruments – 18-Bit, 400-kSPS, Serial Interface, microPower, Miniature, True-Differential Input, SAR Analog-to-Digital Converter

ADS8885
www.ti.com
SBAS568A – MAY 2013 – REVISED DECEMBER 2013
18-Bit, 400-kSPS, Serial Interface, microPower, Miniature,
True-Differential Input, SAR Analog-to-Digital Converter
Check for Samples: ADS8885
FEATURES
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•234 Sample Rate: 400 kHz
• No Latency Output
• Unipolar, True-Differential Input Range:
–V_REF to +V_REF
• Wide Common-Mode Voltage Range:
0 V to V_REF with 90-dB CMRR (min)
• SPI™-Compatible Serial Interface with
Daisy-Chain Option
• Excellent AC and DC Performance:
– SNR: 100 dB, THD: –115 dB
– INL: ±1.5 LSB (typ), ±3.0 LSB (max)
– DNL: +1.5 and –1 LSB (max), 18-Bit NMC
• Wide Operating Range:
– AVDD: 2.7 V to 3.6 V
– DVDD: 1.65 V to 3.6 V
(Independent of AVDD)
– REF: 2.5 V to 5 V (Independent of AVDD)
– Operating Temperature: –40°C to +85°C
• Low-Power Dissipation:
– 2.6 mW at 400 kSPS
– 0.65 mW at 100 kSPS
– 65 µW at 10 kSPS
• Power-Down Current (AVDD): 50 nA
• Full-Scale Step Settling to 18 Bits: 1200 ns
• Packages: MSOP-10 and SON-10
APPLICATIONS
• Automatic Test Equipment (ATE)
• Instrumentation and Process Controls
• Precision Medical Equipment
• Low-Power, Battery-Operated Instruments
DESCRIPTION
The ADS8885 is an 18-bit, 400-kSPS, true-differential
input, analog-to-digital converter (ADC). The device
operates with a 2.5-V to 5-V external reference,
offering a wide selection of signal ranges without
additional input signal scaling. The reference voltage
setting is independent of, and can exceed, the analog
supply voltage (AVDD).
The device offers an SPI-compatible serial interface
that also supports daisy-chain operation for
cascading multiple devices. An optional busy-
indicator bit makes synchronizing with the digital host
easy.
The device supports unipolar, true-differential analog
input signals with a differential input swing of –V_REF to
+V_REF. This true-differential analog input structure
allows for a common-mode voltage of any value in
the range of 0 V to +V_REF (when both inputs are
within the operating input range of –0.1 V to V_REF
+ 0.1 V).
Device operation is optimized for very low-power
operation. Power consumption directly scales with
speed. This feature makes the ADS8885 excellent for
lower-speed applications.
Traditional Input Range
ADS8885 Input Range
0V
V_DIFF
+VREF
-VREF
True-Differential Input Range
VREF
V_CM
VREF
VCM
0V
VREF/2
0 V - VREF
0 V - VREF
2.5 V to 5 V 2.7 V to 3.6 V
AINP
AINM
REF
AVDD
DVDD
DIN
ADS8885
SCLK
DOUT
CONVST
GND
1.65 V to 3.6 V
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Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
TINA is a trademark of Texas Instruments Inc..
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SPI is a trademark of Motorola Inc.
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All other trademarks are the property of their respective owners.
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PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2013, Texas Instruments Incorporated