MAX11040_10 Datasheet, PDF (17/32 Pages) Maxim Integrated Products – 24-Bit, 4-Channel, Simultaneous-Sampling,Cascadable,Sigma-Delta ADC

24-Bit, 4-Channel, Simultaneous-Sampling,
Cascadable, Sigma-Delta ADC
Sampling Instant Control Register
By default, the MAX11040 samples all 4 input channels
simultaneously. To delay the sampling instant on one or
more channels, program the appropriate byte in the
Sampling Instant Control register. The delay of the
actual sampling instant of each individual channel from
the default sampling instant (PHI_[7:0] = 0x00) is
adjustable between 32 to 819,121 XIN clock cycles,
which is 1.3µs to 333µs with f_XINCLOCK at 24.576MHz
(see Table 3.)
Configuration Register
The Configuration register contains 5 bits that control the
functionality of the MAX11040. The default state is 0x00.
The data length of the Configuration register is 8 bits
per cascaded device (see Table 4).
Table 3. Sampling Instant Control Register
BIT
[31:24]
[23:16]
[15:8]
[7:0]
NAME
DESCRIPTION
PHI0[7:0]
Channel 0 sample instant adjust. PHI0 delays sampling instant on channel 0 by 32 XIN clock cycles per
LSB, up to 8192 cycles total (1.3µs resolution; 333µs range at XIN of 24.576MHz).
PHI1[7:0] ^{Channel 1 sample instant adjust. PHI1 delays sampling instant on channel 1 by 32 XIN clock cycles per}
LSB, up to 8192 cycles total (1.3µs resolution; 333µs range at XIN of 24.576MHz).
PHI2[7:0]
Channel 2 sample instant adjust. PHI2 delays sampling instant on channel 2 by 32 XIN clock cycles per
LSB, up to 8192 cycles total (1.3µs resolution; 333µs range at XIN of 24.576MHz).
PHI3[7:0]
Channel 3 sample instant adjust. PHI3 delays sampling instant on channel 3 by 32 XIN clock cycles per
LSB, up to 8192 cycles total (1.3µs resolution; 333µs range at XIN of 24.576MHz).
Table 4. Configuration Register
BIT
NAME
DESCRIPTION
7
SHDN ^{Shutdown bit. Set SHDN high to place the device in shutdown mode. In shutdown mode, the internal}
oscillator, fault circuitry, and internal bandgap reference are turned off. Set SHDN low for normal operation.
6
RST
Reset bit. Set RST high to reset all registers to the default states except for the RST bit, and realign
sampling clocks and output data.
Enable 24-bit resolution bit. Set EN24BIT high to enable the 24-bit data output. Set EN24BIT low to enable
5
EN24BIT 19-bit data output with device address and channel address tags. Tables 5 and 6 specify the Data register
for both states of this bit.
Internal oscillator enable bit. When using the on-chip crystal oscillator as the clock source, set XTALEN high
4
XTALEN
to enable the crystal oscillator and provide a buffered version of the crystal clock at the CLKOUT output.
When using an external clock source, set XTALEN low to disable the internal crystal oscillator and tri-state
the CLKOUT output. Connect the external clock source to the XIN input.
3
[2:0]
FAULTDIS
Overvoltage fault-protection disable bit. Set FAULTDIS high to disable the overvoltage fault-protection
circuits. For FAULTDIS = 0, the absolute maximum input range is ±6V. Analog inputs beyond the fault-
detection threshold range trip the fault-protection circuits. The output remains clipped for a fault-recovery
time (typically < 1.57ms) after the inputs return within the fault-detection threshold range. For FAULTDIS =
1, the absolute maximum input range is only ±3.5V, but there is no fault-recovery delay. See the
Overvoltage Fault Detection and Recovery section.
Don’t Care Don’t-care bits.
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