LTC2439-1 Datasheet, PDF (1/28 Pages) Linear Technology – 8-/16-Channel 16-Bit No Latency Delta-Sigma ADC

LTC2439-1
8-/16-Channel
16-Bit No Latency ∆Σ^TM ADC
FEATURES
s _{16-Channel Single-Ended or 8-Channel Differential}
Inputs
s _{Low Supply Current (200µA, 4µA in Autosleep)}
s _{Rail-to-Rail Differential Input/Reference}
s _{16-Bit No Missing Codes}
s _{1µV RMS Noise, 16-ENOBS Independent of VREF}
s _{Very Low Transition Noise: Less Than 0.02LSB}
s _{Operates with a Reference as Low as 100mV with}
1.5µV LSB Step Size
s _{Guaranteed Modulator Stability and Lock-Up}
Immunity for Any Input and Reference Conditions
s _{Single Supply 2.7V to 5.5V Operation}
s _{Internal Oscillator—No External Components}
Required
s _{87dB Min, 50Hz and 60Hz Simultaneous Notch Filter}
s _{Pin Compatible with the 24-Bit LTC2418}
s _{28-Lead SSOP PUackage}
APPLICATIO S
s _{Direct Sensor Digitizer}
s _{Weight Scales}
s _{Direct Temperature Measurement}
s _{Gas Analyzers}
s _{Strain Gauge Transducers}
s _{Instrumentation}
s _{Data Acquisition}
s _{Industrial Process Control}
DESCRIPTIO
The LTC^®2439-1 is a 16-channel (8-differential)
micropower 16-bit ∆Σ analog-to-digital converter. It op-
erates from 2.7V to 5.5V and includes an integrated
oscillator, 0.12LSB INL and 1µV RMS noise. It uses delta-
sigma technology and provides single cycle settling time
for multiplexed applications. Through a single pin, the
LTC2439-1 can be configured for better than 87dB differ-
ential mode rejection at 50Hz and 60Hz ±2%, or it can be
driven by an external oscillator for a user-defined rejec-
tion frequency. The internal oscillator requires no external
frequency setting components.
The LTC2439-1 accepts any external differential reference
voltage from 0.1V to V_CC for flexible ratiometric and remote
sensing measurement applications. It can be configured
to take 8 differential channels or 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 voltage, V_INCM, may be indepen-
dently set between GND and V_CC. The DC common mode
input rejection is better than 140dB.
The LTC2439-1 communicates 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.
MICROWIRE is a trademark of National Semiconductor Corporation.
TYPICAL APPLICATIO
THERMOCOUPLE
21 CH0
22 CH1
•
•
•
28 CH7
1 CH8
•
•
•
8 CH15
10 COM
16-CHANNEL
MUX
2.7V TO 5.5V
11 9
REF⁺ V_CC
+ DIFFERENTIAL
– ^{16-BIT ∆Σ ADC}
1µF
19
F_O
20
SDI
SCK ¹⁸
17
SDO
16
CS
= EXTERNAL OSCILLATOR
= 50Hz and 60Hz REJECTION
4-WIRE
SPI INTERFACE
12 REF ^–
15 _GND
LTC2439-1
241418 TA01a
Minimum Resolvable
Signal vs V_REF
90
80
70
60
50
40
30
20
10
0
0
1
2
3
4
5
V_REF (V)
24361 TA02
*FOR V_REF = 0.4V RESOLUTION IS LIMITED BY STEP SIZE
24391f
1