MAX1026_11 Datasheet, PDF (15/22 Pages) Maxim Integrated Products – 10-Bit 300ksps ADCs with FIFO, Temp Sensor, Internal Reference

10-Bit 300ksps ADCs with FIFO,
Temp Sensor, Internal Reference
Power-Up Default State
The MAX1026/MAX1028/MAX1030 power up with all
blocks in shutdown, including the reference. All registers
power up in state 00000000, except for the setup regis-
ter, which powers up in clock mode 10 (CKSEL1 = 1).
Temperature Measurements
The MAX1026/MAX1028/MAX1030 perform tempera-
ture measurements with an internal diode-connected
transistor. The diode bias current changes from 68μA
to 4μA to produce a temperature-dependent bias volt-
age difference. The second conversion result at 4μA is
subtracted from the first at 68μA to calculate a digital
value that is proportional to absolute temperature. The
output data appearing at DOUT is the above digital
code minus an offset to adjust from Kelvin to Celsius.
The reference voltage used for the temperature mea-
surements is derived from the internal reference source
to ensure a resolution of 1/8 of a degree.
Output Data Format
Figures 4–7 illustrate the conversion timing for the
MAX1026/MAX1028/MAX1030. The 10-bit conversion
result is output in MSB-first format with 4 leading zeros
and 2 trailing sub-bits. The 12-bit temperature mea-
surement is output with 4 leading zeros. DIN data is
latched into the serial interface on the rising edge of
SCLK. Data on DOUT transitions on the falling edge of
SCLK. Conversions in clock modes 00 and 01 are initiat-
ed by CNVST. Conversions in clock modes 10 and 11
are initiated by writing an input data byte to the conver-
sion register. Data is binary for unipolar mode and two’s
complement for bipolar mode.
Table 4. Unipolar Mode Register (Addressed Through Setup Register)
BIT NAME
UCH0/1
UCH2/3
UCH4/5
UCH6/7
UCH8/9
UCH10/11
UCH12/13
UCH14/15
BIT
7 (MSB)
6
5
4
3
2
1
0 (LSB)
FUNCTION
Set to 1 to configure AIN0 and AIN1 for unipolar differential conversion.
Set to 1 to configure AIN2 and AIN3 for unipolar differential conversion.
Set to 1 to configure AIN4 and AIN5 for unipolar differential conversion.
Set to 1 to configure AIN6 and AIN7 for unipolar differential conversion.
Set to 1 to configure AIN8 and AIN9 for unipolar differential conversion (MAX1028/MAX1030 only).
Set to 1 to configure AIN10 and AIN11 for unipolar differential conversion (MAX1028/MAX1030 only).
Set to 1 to configure AIN12 and AIN13 for unipolar differential conversion (MAX1030 only).
Set to 1 to configure AIN14 and AIN15 for unipolar differential conversion (MAX1030 only).
Table 5. Bipolar Mode Register (Addressed Through Setup Register)
BIT NAME
BCH0/1
BCH2/3
BCH4/5
BCH6/7
BCH8/9
BCH10/11
BCH12/13
BCH14/15
BIT
7 (MSB)
6
5
4
3
2
1
0 (LSB)
FUNCTION
Set to 1 to configure AIN0 and AIN1 for bipolar differential conversion.
Set to 1 to configure AIN2 and AIN3 for bipolar differential conversion.
Set to 1 to configure AIN4 and AIN5 for bipolar differential conversion.
Set to 1 to configure AIN6 and AIN7 for bipolar differential conversion.
Set to 1 to configure AIN8 and AIN9 for bipolar differential conversion (MAX1028/MAX1030 only).
Set to 1 to configure AIN10 and AIN11 for bipolar differential conversion (MAX1028/MAX1030 only).
Set to 1 to configure AIN12 and AIN13 for bipolar differential conversion (MAX1030 only).
Set to 1 to configure AIN14 and AIN15 for bipolar differential conversion (MAX1030 only).
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