Datasheet

Measurement Computing [phone]
4
[e-mail] mccdaq.com
MCC 128
All specifications are subject to change without notice.
Typical for 25 ˚C unless otherwise specified.
Analog Input
A/D converter type: Successive approximation
ADC resolution: 16 bits
Input modes
Single ended (CHx – AGND)
Differential (CHxH – CHxL)
Number of channels: 8 single-ended or 4 differential; software selectable
Input voltage ranges: ±10 V, ±5 V, ±2 V, ±1 V
Absolute maximum input voltage
CHx relative to AGND: ±30 V max (power on), ±20 V max (power off)
Input impedance: >1 GΩ
Input bias current: ±200 pA, typ
INL: ±1.8 LSB
DNL: 16 bits no missing codes
CMRR, DC to 5 kHz
±10 V range: 56 dB
±5 V range: 57 dB
±2 V range: 61 dB
±1 V range: 65 dB
Input bandwidth, small signal (-3 dB): 220 kHz
Maximum working voltage: Input range relative to AGND: ±10.1 V max
Crosstalk: Adjacent channels, DC to 10 kHz: -70 dB
Input coupling: DC
Recommended warm up time: 1 minute min
Sampling rate, hardware paced
Internal scan clock: 1 S/s to 100 kS/s, software-selectable
External scan clock : 100 kS/s max
Sampling mode: One A/D conversion for each configured channel per clock
Conversion time, per channel: 9.8 µs
Scan clock source: Internal scan clock, External scan clock input on terminal CLK
Channel queue: Up to eight unique, ascending channels in a single range and mode
Throughput (dependent on the load on the Raspberry Pi processor. The highest
throughput may be achieved by using a Raspberry Pi 3 B+.)
Raspberry Pi
®
2 / 3 / 4
Single board: 100 kS/s max
Multiple boards: Up to 320 kS/s aggregate
Raspberry Pi A+ / B+
Single board: Up to 100 kS/s
Multiple boards: Up to 100 kS/s aggregate
Accuracy
Analog input DC voltage measurement accuracy
Range At full scale
(typ at 25 °C)
At full scale
(maximum over temperature)
SE ±10 V ±6 mV ±34 mV
SE ±5 V ±3 mV ±17 mV
SE ±2 V ±1.2 mV ±7 mV
SE ±1 V ±600 µV ±3.4 mV
DIFF ±10 V ±14 mV ±42 mV
DIFF ±5 V ±6.5 mV ±21 mV
DIFF ±2 V ±2.1 mV ±8 mV
DIFF ±1 V ±900 µV ±3.7 mV
Noise Performance
Range Vrms
±10 V 350 µV
±5 V 220 µV
±2 V 150 µV
±1 V 100 µV
For the peak to peak noise distribution test, the input channel is in single-ended
mode connected to AGND at the input terminal block, and 100,000 samples are
acquired at the maximum throughput. The performance is the same for single-
ended and differential mode
External Digital Trigger
Trigger source: TRIG input
Trigger mode: Software-selectable for rising or falling edge, or high or low level
Trigger latency:
Internal scan clock: 1 µs max
External scan clock: 1 µs + 1 scan clock cycle max
Trigger pulse width: 125 ns min
Input type: Schmitt trigger, 100 kΩ pull-down to ground
Input high voltage threshold: 1.3 V min
Input low voltage threshold: 1.5 V max
Input hysteresis: 0.4 V max
Input voltage limits: 5.5 V absolute max, –0.5 V absolute min, 0 V recom-
mended min
External Scan Clock Input/Output
Terminal name: CLK
Terminal types: Bidirectional, defaults to input when not sampling analog channels
Direction (software-selectable):
Output: Outputs internal scan clock, active on rising edge
Input: Receives scan clock from external source, active on rising edge
Input clock rate: 100 kHz max
Clock pulse width: 400 ns min
Input type: Schmitt trigger, 100 kΩ pull-down to ground
Input high voltage threshold: 1.3 V min
Input low voltage threshold: 1.5 V max
Input hysteresis: 0.4 V max
Input voltage limits: 5.5 V absolute max, –0.5 V absolute min, 0 V recom-
mended min
Output high voltage: 3.0 V min (IOH = –100 µA), 2.4 V min (IOH = –4 mA)
Output low voltage: 0.1 V max (IOL = 100 µA), 0.4 V max (IOL = 4 mA)
Output current: ±4 mA max
Memory
Data FIFO: 7 K (73,728) analog input samples
Non-volatile memory: 4 KB (ID and calibration storage, no user-modifiable
memory)
Power
Supply current, 5 V supply:
Typical: 85 mA
Maximum: 135 mA
Interface
Raspberry Pi GPIO pins used:
GPIO 8, GPIO 9, GPIO 10, GPIO 11 (SPI interface)
ID_SD, ID_SC (ID EEPROM)
GPIO 12, GPIO 13, GPIO 26 (Board address)
GPIO16, 20 (Reset, IRQ)
Data interface type: SPI slave device, CE0 chip select
SPI mode: 1
SPI clock rate: 10 MHz, max
Environment
Operating temperature: 0 °C to 55 °C
Storage temperature: –40 ˚C to 85 °C max
Relative humidity: 0% to 90% non-condensing
Mechanical
Dimensions (L × W × H): 65 × 56.5 × 12 mm (2.56 × 2.22 × 0.47 in.) max
Specifications