LTC2428CG Linear Technology, LTC2428CG Datasheet - Page 34
![IC ADC 20BIT 8CH MICROPWR 28SSOP](/photos/6/59/65971/161-28-ssop_sml.jpg)
LTC2428CG
Manufacturer Part Number
LTC2428CG
Description
IC ADC 20BIT 8CH MICROPWR 28SSOP
Manufacturer
Linear Technology
Datasheet
1.LTC2424CGPBF.pdf
(36 pages)
Specifications of LTC2428CG
Number Of Bits
20
Sampling Rate (per Second)
7.5
Data Interface
MICROWIRE™, Serial, SPI™
Number Of Converters
1
Power Dissipation (max)
1mW
Voltage Supply Source
Single Supply
Operating Temperature
0°C ~ 70°C
Mounting Type
Surface Mount
Package / Case
28-SSOP (0.200", 5.30mm Width)
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Part Number:
LTC2428CG
Manufacturer:
LINEAR/凌特
Quantity:
20 000
Part Number:
LTC2428CGN
Manufacturer:
LINEAR/凌特
Quantity:
20 000
APPLICATIONS
LTC2424/LTC2428
could be used to measure the case temperature of the
RTD-based thermal power measurement scheme described
previously. In general, thermistors yield very good resolu-
tion over a limited temperature range. For the half-bridge
arrangement shown, the LTC2428 can measure tempera-
ture changes over nearly 5 orders of magnitude.
Connected to the LTC2428’s CH6 input, an infrared ther-
mocouple (Omega Engineering OS36-1) can be used in
limited range, noncontact temperature measurement ap-
plications or applications where high levels of infrared
light must be measured. Given the LTC2428’s 1.2ppm
noise performance, measurement resolution using infra-
red thermocouples is approximately 0.25 C—equivalent
to the resolution of a conventional Type J thermocouple.
These infrared thermocouples are self-contained: 1) they
do not require external cold junction compensation; 2)
they cannot use conventional open thermocouple detec-
tion schemes; and 3) their output impedances are high,
approximately 3k . Alternatively, conventional thermo-
couples can be connected directly to the LTC2428 (not
shown) and cold junction compensation can be provided
by an external temperature sensor connected to a different
34
U
INFORMATION
U
W
U
RMS
channel (see the thermistor circuit on CH5) or by using the
LT1025, a monolithic cold-junction compensator IC.
The components connected to CH7 are used to sense
daylight or photodiode current with a resolution of 300pA.
In the figure, the photodiode is biased in photoconduc-
tive mode; however, the LTC2428 can accommodate
either photovoltaic or photoconductive configurations.
The photodiode chosen (Hammatsu S1336-5BK) pro-
duces an output of 500mA per watt of optical illumination.
The output of the photodiode is dependent on two factors:
active detector area (2.4mm • 2.4mm) and illumination
intensity. With the 5k resistor, optical intensities up to
368W/m
1000W/m
resolution of 1nA, the optical dynamic range covers 5
orders of magnitude.
The application circuits shown connected to the LTC2428
demonstrate the mix-and-match capabilities of this multi-
plexed-input, high resolution
signals and high level signals can be accommodated with
a minimum of additional circuitry.
2
2
at 960nM (direct sunlight is approximately
) can be measured by the LTC2428. With a
ADC. Very low level