LTC2498IUHF#PBF Linear Technology, LTC2498IUHF#PBF Datasheet - Page 20

• Manufacturer Part Number: LTC2498IUHF#PBF
• Description: IC ADC 24BIT 16CH 38-QFN
• Manufacturer: Linear Technology

Specifications of LTC2498IUHF#PBF

• Number Of Bits: 24
• Sampling Rate (per Second): 7.5
• Data Interface: MICROWIRE™, Serial, SPI™
• Number Of Converters: 1
• Power Dissipation (max): 480µW
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 38-WFQFN, Exposed Pad
• Number Of Elements: 1
• Resolution: 24Bit
• Architecture: Delta-Sigma
• Sample Rate: 0.008KSPS
• Input Polarity: Bipolar
• Input Type: Voltage
• Rated Input Volt: ±2.75V
• Differential Input: Yes
• Power Supply Requirement: Single
• Single Supply Voltage (typ): 3.3/5V
• Single Supply Voltage (min): 2.7V
• Single Supply Voltage (max): 5.5V
• Dual Supply Voltage (typ): Not RequiredV
• Dual Supply Voltage (min): Not RequiredV
• Dual Supply Voltage (max): Not RequiredV
• Integral Nonlinearity Error: 10ppm of Vref
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 38
• Package Type: QFN EP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

applications inForMation
LTC2498
up to 15Hz with no latency). When IM = 1 (temperature
measurement), SPD will be ignored and the device will
operate in 1x mode. The configuration remains valid until
a new input word with EN = 1 (the first 3 bits are 101) and
EN2 = 1 is shifted into the device.
Rejection Mode (FA, FB)
The LTC2498 includes a high accuracy on-chip oscillator
with no required external components. Coupled with an
integrated 4th order digital lowpass filter, the LTC2498 re-
jects line frequency noise. In the default mode, the LTC2498
simultaneously rejects 50Hz and 60Hz by at least 87dB. If
more rejection is required, the LTC2498 can be configured
to reject 50Hz or 60Hz to better than 110dB.
Speed Mode (SPD)
Every conversion cycle, two conversions are combined to
remove the offset (default mode). This result is free from
offset and drift. In applications where the offset is not
critical, the auto-calibration feature can be disabled with
the benefit of twice the output rate. While operating in the
2x mode (SPD = 1), the linearity and full-scale errors are
0
Table 4. Converter Configuration
1
1
1
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
EN
0
1
0
1
1
1
1
1
1
1
1
SGL
X
X
X
X
X
X
X
X
X
X
X
ODD
X
X
X
X
X
X
X
X
X
X
X
A2
X
X
X
X
X
X
X
X
X
X
X
A1
X
X
X
X
X
X
X
X
X
X
X
A0
X
X
X
X
X
X
X
X
X
X
X
EN2
X
0
X
1
1
1
1
1
1
1
1
unchanged from the 1x mode performance. In both the 1x
and 2x mode there is no latency. This enables input steps
or multiplexer changes to settle in a single conversion
cycle easing system overhead and increasing the effective
conversion rate. During temperature measurements, the 1x
mode is always used independent of the value of SPD.
Temperature Sensor
The LTC2498 includes an integrated temperature sensor.
The temperature sensor is selected by setting IM = 1.
During temperature readings, MUXOUTN/MUXOUTP
remains connected to the selected input channel. The
ADC internally connects to the temperature sensor and
performs a conversion.
The digital output is proportional to the absolute tem-
perature of the device. This feature allows the converter
to perform cold junction compensation for external
thermocouples or continuously remove the temperature
effects of external sensors.
The internal temperature sensor output is 28mV at 27°C
(300°K), with a slope of 93.5µV/°C independent of V
IM
X
X
X
0
0
0
0
0
1
1
1
FA
X
X
X
0
0
1
0
0
0
0
1
FB
X
X
X
0
1
0
0
1
0
1
0
SPD
X
X
X
X
X
X
0
0
0
1
1
Keep Previous (Change Channel)
CONVERTER CONFIGURATION
External Input (See Table 3)
External Input (See Table 3)
External Input (See Table 3)
External Input (See Table 3)
External Input (See Table 3)
50Hz/60Hz Rejection, 1x
50Hz/60Hz Rejection, 2x
50Hz/60Hz Rejection, 1x
Measure Temperature
Measure Temperature
Measure Temperature
50Hz Rejection, 1x
60Hz Rejection, 1x
50Hz Rejection, 2x
50Hz Rejection, 1x
60Hz Rejection, 1x
Keep Previous
Keep Previous
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REF
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