LTC2420IS8#PBF Linear Technology, LTC2420IS8#PBF Datasheet - Page 36

• Manufacturer Part Number: LTC2420IS8#PBF
• Description: IC ADC 20BIT MICRPWR W/OSC 8SOIC
• Manufacturer: Linear Technology

Specifications of LTC2420IS8#PBF

• Number Of Bits: 20
• Sampling Rate (per Second): 7.5
• Data Interface: MICROWIRE™, Serial, SPI™
• Number Of Converters: 2
• Power Dissipation (max): 1mW
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

RELATED PARTS
PART NUMBER
LT1019
LT1025
LTC1043
LTC1050
LT1236A-5
LTC1391
LT1460
LTC2400
LTC2401/LTC2402
LTC2404/LTC2408
LTC2410
LTC2411
LTC2413
LTC2424/LTC2428
TYPICAL APPLICATIO
LTC2420
36
The circuit shown in Figure 41 enables pseudodifferential
measurements of several bridge transducers and abso-
lute temperature measurement. The LTC1391 is an
8-to-1 analog multiplexer.
Consecutive readings are performed on each side of the
bridge by selecting the appropriate channel on the
LTC1391. Each output is digitized and the results digitally
subtracted to obtain the pseudodifferential result. Several
bridge transducers may be digitized in this manner.
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] FAX: [phone] www.linear-tech.com
THERMISTOR
DESCRIPTION
Precision Bandgap Voltage Reference, 2.5V, 5V
Micropower Thermocouple Cold Junction Compensator
Dual Precision Instrumentation Switched Capacitor
Building Block
Precision Chopper Stabilized Op Amp
8-Channel Multiplexer
Micropower Series Voltage Reference
24-Bit Power, No Latency
1-/2-Channel, 24-Bit No Latency
4-/8-Channel, 24-Bit No Latency
24-Bit No Latency
24-Bit No Latency
24-Bit No Latency
4-/8-Channel 20-Bit No Latency
Precision Bandgap Voltage Reference, 5V
THERMOCOUPLE
Figure 41. Pseudodifferential Multichannel Bridge Digitizer
and Digital Cold Junction Compensation
U
ADC with Differential Inputs
ADC with Differential Inputs/Reference
ADC
ADC in SO-8
ADCs
ADC
ADCs
In order to measure absolute temperature with a thermo-
couple, cold junction compensation must be performed.
Channel 6 measures the output of the thermocouple while
channel 7 measures the output of the cold junction sensor
(diode, thermistor, etc.). This enables digital cold junc-
tion compensation of the thermocouple output. The tem-
perature measurement may then be used to compensate
the temperature effects of the bridge transducers.
COMMENTS
3ppm/ C Drift, 0.05% Max
0.5 C Initial Accuracy, 80 A Supply Current
Precise Charge, Balanced Switching, Low Power
No External Components 5 V Offset, 1.6 V
0.05% Max, 5ppm/ C Drift
Low R
0.075% Max, 10ppm/ C Max Drift, 2.5V, 5V and 10V Versions
4ppm INL, 10ppm TUE, 200 A, Pin Compatible with LTC2420
24 Bits in MSOP Package
4ppm INL, 10ppm TUE, 200 A
800nV Noise, Differential Reference, 2.7V to 5.5V Operation
1.6 V Noise, Fully Differential, 10-Lead MSOP Package
Simultaneous 50Hz to 60Hz Rejection 0.16ppm Noise
8ppm INL, 1.2ppm Noise, Fast Mode
ON
CH0
CH1
CH2
CH3
CH4
CH5
CH6
CH7
: 45 , Low Charge Injection, Serial Interface
LTC1391
GND
OUT
V
CC
V
GND
V
LTC2420
IN
REF
V
SDO
SCK
CC
LINEAR TECHNOLOGY CORPORATION 2000
CS
F
O
2420f LT/LCG 1000 4K • PRINTED IN USA
P-P
2420 F41
Noise