MAX11040_10 Datasheet, PDF (8/32 Pages) Maxim Integrated Products – 24-Bit, 4-Channel, Simultaneous-Sampling,Cascadable,Sigma-Delta ADC

24-Bit, 4-Channel, Simultaneous-Sampling,
Cascadable, Sigma-Delta ADC
Typical Operating Characteristics (continued)
(V_AVDD = V_DVDD = 3.3V, f_{XIN CLOCK} = 24.576MHz, f_OUT = 16ksps, V_REFIO = 2.5V (external), C_REFIO = C_REF0 = C_REF1 = C_REF2 =
C_REF3 = 1µF, T_A = +25°C, unless otherwise noted.)
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
1000
AVDD = DVDD = 3.6V
CRYSTAL OSCILLATOR STARTUP TIME
MAX11040 toc20
800
600
I_AVDD
400
200
I_DVDD
CLKOUT
500mV/div
0
-40 -11
18
47
76 105
TEMPERATURE (°C)
40μs/div
Pin Description
PIN
1
2
3
4, 8, 10,
29, 31, 35
5
6
7
9
11, 28
12, 27
13
NAME
AIN0-
AIN0+
REF0
FUNCTION
Negative Analog Input Channel 0
Positive Analog Input Channel 0
ADC0 Buffered Reference Voltage. Bypass REF0 with a 1µF capacitor to AGND.
AGND Analog Ground
AIN1-
AIN1+
REF1
REFIO
DGND
DVDD
CASCIN
Negative Analog Input Channel 1
Positive Analog Input Channel 1
ADC1 Buffered Reference Voltage. Bypass REF1 with a 1µF capacitor to AGND.
Reference Voltage Output/Input. Reference voltage for analog-to-digital conversion. In internal reference
mode, the reference buffer provides a +2.5V nominal output. In external reference mode, overdrive REFIO
with an external reference between 2.3V to 2.7V. Bypass REFIO with a 1µF capacitor to AGND.
Digital Ground
Positive Digital Supply Voltage. Bypass each DVDD to DGND with a 1µF capacitor in parallel with a
0.01µF capacitor as close as possible to the device.
Cascade Input. A logic-low on CASCIN while CS is a logic-low during the last cycle of a byte signals the
device to perform the requested data transfer during subsequent bytes using DIN and DOUT. Once the
requested transfer is completed, the part three-states DOUT and ignores DIN until a new command is
issued. CASCIN is clocked in at the rising edge of SCLK. Connect CASCIN to DGND when not daisy
chaining multiple devices. See the Multiple Device Connection section for connection recommendations.
Cascade Output. CASCOUT is driven low during the last cycle of the last byte of a data transfer to signal
14
CASCOUT
the next device in the daisy chain to begin transferring data on the next byte. CASCOUT changes after the
rising edge of SCLK. Leave CASCOUT unconnected when not daisy chaining multiple devices. See the
Multiple Device Connection section.
Active-Low Chip-Select Input. A falling edge on CS while CASCIN is a logic-low enables DIN and DOUT
15
CS
for data transfer. A logic-high on CS prevents data from being clocked in on DIN and places DOUT in a
high-impedance state.
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