MAX1402EVKIT Maxim Integrated Products, MAX1402EVKIT Datasheet - Page 25

• Manufacturer Part Number: MAX1402EVKIT
• Description: EVAL KIT FOR MAX1402
• Manufacturer: Maxim Integrated Products

Specifications of MAX1402EVKIT

• Number Of Adc's: 1
• Number Of Bits: 18
• Sampling Rate (per Second): 480
• Data Interface: Serial
• Inputs Per Adc: 6 Single Ended
• Input Range: ±VREF/2
• Power (typ) @ Conditions: 26.7mW @ 480SPS
• Voltage Supply Source: Analog and Digital
• Operating Temperature: 0°C ~ 70°C
• Utilized Ic / Part: MAX1402
• Interface Type: SMA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: MAX1402

The MAX1402 provides a pair of input buffers to isolate
the inputs from the capacitive load presented by the
PGA/modulator (Figure 6). The buffers are chopper sta-
bilized to reduce the effect of their DC offsets and low-
frequency noise. Since the buffers can represent more
than 50% of the total analog power dissipation, they may
be shut down in applications where minimum power dis-
sipation is required and the capacitive input load is not a
concern. Disable the buffers in applications where the
inputs must operate close to AGND or V+.
Table 13c. R
Mode—4x Modulator Sampling Frequency (MF1, MF0 = 10 ); X2CLK = 0; CLKIN =
2.4576MHz
Table 13d. R
Mode—8x Modulator Sampling Frequency (MF1, MF0 = 11); X2CLK = 0; CLKIN =
2.4576MHz
Figure 6. Analog Input, Buffered Mode (BUFF = 1)
PGA GAIN
PGA GAIN
8, 16, 32,
8, 16, 32,
64, 128
64, 128
1
2
4
1
2
4
R
EXT
EXT
EXT
C
______________________________________________________________________________________
EXT
C
C
, C
EXT
EXT
, C
11.1
11.1
8.3
5.5
5.4
5.4
4.0
2.7
+5V, 18-Bit, Low-Power, Multichannel,
EXT
EXT
= 0pF
= 0pF
Values for Less than 16-Bit Gain Error in Unbuffered (BUFF = 0)
Values for Less than 16-Bit Gain Error in Unbuffered (BUFF = 0)
C
PIN
R
MUX
Oversampling (Sigma-Delta) ADC
C
C
EXT
EXT
4.9
4.9
4.2
3.3
2.4
2.4
2.1
1.6
= 50pF
= 50pF
Input Buffers
C
ST
EXTERNAL RESISTANCE R
EXTERNAL RESISTANCE R
R
IN
C
C
EXT
EXT
3.2
3.2
2.9
2.4
1.6
1.6
1.4
1.2
= 100pF
= 100pF
When used in buffered mode, the buffers isolate the
inputs from the sampling capacitors. The sampling-
related gain error is dramatically reduced in this mode.
A small dynamic load remains from the chopper stabi-
lization. The multiplexer exhibits a small input leakage
current of up to 10nA. With high source resistances,
this leakage current may result in a DC offset.
The MAX1402 is optimized for ratiometric measure-
ments and includes a fully differential reference input.
Apply the reference voltage across REFIN+ and REFIN-,
C
AMP
C
C
EXT
EXT
0.95
0.95
0.89
0.81
0.47
0.47
0.43
0.39
= 500pF
= 500pF
EXT
EXT
(kΩ)
(kΩ)
C
SAMPLE
C
C
EXT
EXT
0.54
0.54
0.50
0.46
0.26
0.26
0.25
0.23
= 1000pF
= 1000pF
Reference Input
C
C
C
EXT
EXT
C
0.069
0.069
0.064
0.059
0.14
0.14
0.13
0.12
= 5000pF
= 5000pF
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