ADS8881C Datasheet, PDF (1/57 Pages) Texas Instruments – ADS8881x 18-Bit, 1-MSPS, Serial Interface, microPower, Miniature, True-Differential Input, SAR Analog-to-Digital Converter

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ADS8881C, ADS8881I
SBAS547C – MAY 2013 – REVISED JULY 2014
ADS8881x 18-Bit, 1-MSPS, Serial Interface, microPower, Miniature,
True-Differential Input, SAR Analog-to-Digital Converter
1 Features
•1 Sample Rate: 1 MHz
• 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:
– ADS8881C:
INL: ±1 LSB (typ), ±2.0 LSB (max)
DNL: ±1.0 LSB (max), 18-Bit NMC
SNR: 100 dB, THD: –115 dB
– ADS8881I:
INL: ±1.5 LSB (typ), ±3.0 LSB (max)
DNL: +1.5 and –1 LSB (max), 18-Bit NMC
SNR: 100 dB, THD: –115 dB
• Wide Operating Range:
– AVDD: 2.7 V to 3.6 V
– DVDD: 2.7 V to 3.6 V
(Independent of AVDD)
– REF: 2.5 V to 5 V (Independent of AVDD)
– Operating Temperature:
ADS8881C : 0°C to +70°C
ADS8881I : –40°C to +85°C
• Low-Power Dissipation:
– 5.5 mW at 1 MSPS
– 0.55 mW at 100 kSPS
– 55 µW at 10 kSPS
• Power-Down Current (AVDD): 50 nA
• Full-Scale Step Settling to 18 Bits: 290 ns
• Packages: MSOP-10 and VSON-10
2 Applications
• Automatic Test Equipment (ATE)
• Instrumentation and Process Controls
• Precision Medical Equipment
• Low-Power, Battery-Operated Instruments
3 Description
The ADS8881 is an 18-bit, 1-MSPS, 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 ADS8881 excellent for
lower-speed applications.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
ADS8881x
VSSOP (10)
VSON (10)
3.00 mm × 3.00 mm
3.00 mm × 3.00 mm
(1) For all available packages, see the orderable addendum at
the end of the datasheet.
Traditional Input Range
ADS8881 Input Range
0V
VDIFF
+VREF
-VREF
True-Differential Input Range
VREF
VCM
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
ADS8881
SCLK
DOUT
CONVST
GND
2.7 V to 3.6 V
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.