LTC2414_15 Datasheet, PDF (1/48 Pages) Linear Technology – 8-/16-Channel 24-Bit No Latency ADCs

LTC2414/LTC2418
8-/16-Channel
24-Bit No Latency ∆Σ^TM ADCs
FEATURES
■ _{8-/16-Channel Single-Ended or 4-/8-Channel}
Differential Inputs (LTC2414/LTC2418)
■ _{Low Supply Current (200µA, 4µA in Autosleep)}
■ _{Differential Input and Differential Reference}
with GND to V_CC Common Mode Range
■ _{2ppm INL, No Missing Codes}
■ _{2.5ppm Full-Scale Error and 0.5ppm Offset}
■ _{0.2ppm Noise}
■ _{No Latency: Digital Filter Settles in a Single Cycle}
Each Conversion Is Accurate, Even After a New
Channel is Selected
■ _{Single Supply 2.7V to 5.5V Operation}
■ _{Internal Oscillator—No External Components}
Required
■ _{110dB Min, 50Hz/60Hz Notch Filter}
U
APPLICATIO S
■ _{Direct Sensor Digitizer}
■ _{Weight Scales}
■ _{Direct Temperature Measurement}
■ _{Gas Analyzers}
■ _{Strain Gauge Transducers}
■ _{Instrumentation}
■ _{Data Acquisition}
■ _{Industrial Process Control}
DESCRIPTIO
The LTC^®2414/LTC2418 are 8-/16-channel (4-/8-differ-
ential) micropower 24-bit ∆Σ analog-to-digital convert-
ers. They operate from 2.7V to 5.5V and include an
integrated oscillator, 2ppm INL and 0.2ppm RMS noise.
They use delta-sigma technology and provide single cycle
settling time for multiplexed applications. Through a
single pin, the LTC2414/LTC2418 can be configured for
better than 110dB differential mode rejection at 50Hz or
60Hz ±2%, or they can be driven by an external oscillator
for a user-defined rejection frequency. The internal oscil-
lator requires no external frequency setting components.
The LTC2414/LTC2418 accept any external differential
reference voltage from 0.1V to V_CC for flexible ratiometric
and remote sensing measurement applications. They can
be configured to take 4/8 differential channels or
8/16 single-ended channels. The full-scale bipolar input
range is from – 0.5V_REF to 0.5V_REF. The reference common
mode voltage, V_REFCM, and the input common mode volt-
age, V_INCM, may be independently set within GND to V_CC.
The DC common mode input rejection is better than 140dB.
The LTC2414/LTC2418 communicate through a flexible
4-wire digital interface that is compatible with SPI and
MICROWIRE^TM protocols.
, LTC and LT are registered trademarks of Linear Technology Corporation.
No Latency ∆Σ is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners.
TYPICAL APPLICATIO
2.7V TO 5.5V
THERMOCOUPLE
21 CH0
22 CH1
•
•
•
28 CH7
1 CH8
•
•
•
8 CH15
10 COM
16-CHANNEL
MUX
11 9
REF⁺ V_CC
+ DIFFERENTIAL
– ^{24-BIT ∆Σ ADC}
1µF
19
F_O
V_CC
= 50Hz REJECTION
= EXTERNAL OSCILLATOR
= 60Hz REJECTION
SDI ²⁰
18
SCK
SDO ¹⁷
16
CS
4-WIRE
SPI INTERFACE
12 REF ^–
15 _GND
LTC2418
241418 TA01a
Total Unadjusted Error
vs Input Voltage
3
V_CC = 5V
V_REF = 5V
2 V_INCM = V_REFCM = 2.5V
F_O = GND
1
T_A = 25°C
0
T_A = –45°C
–1
T_A = 85°C
–2
–3
–2.5 –2 –1.5 –1 –0.5 0 0.5 1.0 1.5 2.0 2.5
INPUT VOLTAGE (V)
2414/18 TA01b
241418fa
1