Measurement Computing USB-1608G-OEM User manual

USB-1608G-OEM
High-speed Multifunction DAQ
Document Revision 2
January 2015
© Copyright 2015
User's Guide

HM USB-1608G-OEM
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3
Table of Contents
Preface
About this User's Guide .......................................................................................................................5
What you will learn from this user's guide .........................................................................................................5
Conventions in this user's guide .........................................................................................................................5
Where to find more information.........................................................................................................................5
Chapter 1
Introducing the USB-1608G-OEM........................................................................................................6
Functional block diagram...................................................................................................................................6
Chapter 2
Installing the USB-1608G-OEM............................................................................................................7
Unpacking...........................................................................................................................................................7
Downloading the software..................................................................................................................................7
Installing the hardware .......................................................................................................................................7
Installing on a Windows platform..................................................................................................................................... 7
Installing on an Android platform..................................................................................................................................... 7
Calibrating the hardware.....................................................................................................................................8
Factory calibration............................................................................................................................................................ 8
Field calibration................................................................................................................................................................ 8
Firmware updates ...............................................................................................................................................8
Chapter 3
Functional Details .................................................................................................................................9
Analog input modes............................................................................................................................................9
Software paced.................................................................................................................................................................. 9
Hardware paced ................................................................................................................................................................ 9
Burst mode..........................................................................................................................................................9
Board components............................................................................................................................................10
USB connector.................................................................................................................................................................10
LEDs................................................................................................................................................................................10
Header connectors............................................................................................................................................................10
Signal connections............................................................................................................................................12
Analog input....................................................................................................................................................................12
External clock I/O............................................................................................................................................................13
Digital I/O........................................................................................................................................................................14
Trigger input....................................................................................................................................................................14
Counter input...................................................................................................................................................................15
Timer output....................................................................................................................................................................15
Power output....................................................................................................................................................................15
Ground.............................................................................................................................................................................15
Mechanical drawings........................................................................................................................................16
Chapter 4
Specifications......................................................................................................................................17
Analog input.....................................................................................................................................................17
Accuracy...........................................................................................................................................................18
Analog input DC voltage measurement accuracy............................................................................................................18
Noise performance...........................................................................................................................................................18
Settling time.....................................................................................................................................................................18
Analog input calibration...................................................................................................................................18
Digital input/output...........................................................................................................................................19
External trigger.................................................................................................................................................19
External clock input/output...............................................................................................................................20

USB-1608G-OEM User's Guide
4
Counter.............................................................................................................................................................20
Timer ................................................................................................................................................................21
Memory ............................................................................................................................................................21
Power................................................................................................................................................................21
USB ..................................................................................................................................................................21
Environmental ..................................................................................................................................................22
Mechanical .......................................................................................................................................................22
Header connector..............................................................................................................................................22
Pin orientation..................................................................................................................................................................22
Differential mode pinout..................................................................................................................................................23
Single-ended mode pinout ...............................................................................................................................................24

5
Preface
About this User's Guide
What you will learn from this user's guide
This user's guide describes the Measurement Computing USB-1608G-OEM data acquisition devices and lists
device specifications.
Conventions in this user's guide
For more information about …
Text presented in a box signifies additional information and helpful hints related to the subject matter you are
reading.
Caution! Shaded caution statements present information to help you avoid injuring yourself and others,
damaging your hardware, or losing your data.
bold text Bold text is used for the names of objects on a screen, such as buttons, text boxes, and check boxes.
italic text Italic text is used for the names of manuals and help topic titles, and to emphasize a word or phrase.
Where to find more information
Additional information about USB-1608G-OEM hardware is available on our website at www.mccdaq.com.
You can also contact Measurement Computing Corporation by phone, fax, or email with specific questions.
Knowledgebase: kb.mccdaq.com
Tech support form: www.mccdaq.com/support/support_form.aspx
Email: [e-mail]
Phone: [phone] and follow the instructions for reaching Tech Support
For international customers, contact your local distributor. Refer to the International Distributors section on our
website at www.mccdaq.com/International.

6
Chapter 1
Introducing the USB-1608G-OEM
The USB-1608G-OEM is a USB 2.0 high-speed device provides the following features:
16 single-ended (SE) or eight differential (DIFF) analog input channels
Eight individually configurable digital I/O channels
Two counter channels (32-bit) that count TTL pulses
One timer output channel (32-bit)
Header connectors for field wiring connections
The USB-1608G-OEM device is compatible with both USB 1.1 and USB 2.0 ports. The speed of the device
may be limited when using a USB 1.1 port due to the difference in transfer rates on the USB 1.1 versions of the
protocol (low-speed and full-speed).
The USB-1608G-OEM is powered by the +5 volt USB supply from your computer, and requires no external
power.
Caution! There are no product safety, electromagnetic compatibility (EMC), or CE marking compliance
claims made for the USB-1608G-OEM. The USB-1608G-OEM is intended for use as a
component of a larger system. MCC can help developers meet their compliance requirements. The
end product supplier, however, is responsible for conforming to any and all compliance
requirements.
Functional block diagram
USB-1608G-OEM functions are illustrated in the block diagram shown here.
Figure 1. Functional block diagram

7
Chapter 2
Installing the USB-1608G-OEM
Unpacking
As with any electronic device, you should take care while handling to avoid damage from static
electricity. Before removing the board from its packaging, ground yourself using a wrist strap or by simply
touching the computer chassis or other grounded object to eliminate any stored static charge.
Downloading the software
Refer to the USB-1608G-OEM product page on the Measurement Computing website for information about the
supported software you can download.
Install the software before you install the hardware
The driver needed to run the device is installed when you install the software. Therefore, you need to install the
software package you plan to use before you install the hardware.
Installing the hardware
Installing on a Windows platform
Install the software before you install your device
A driver needed to run the USB-1608G-OEM is installed when you install the software. Therefore, you need to
install the software package you plan to use before you install the hardware.
For operation on a Windows operating system, we recommend that you run Windows Update to update your
operating system with the latest USB drivers.
To connect the USB-1608G-OEM to your system, turn on your computer and connect the USB cable to an
available USB port on the computer or to an external USB hub connected to the computer. Connect the other
end of the USB cable to the USB connector on the device. No external power is required.
When you connect the device for the first time to a computer running Windows, a Found New Hardware dialog
opens when the operating system detects the device. The dialog closes after the device is installed.
A green Status LED indicates the device status. When the Status LED is on, the device is powered and ready
for operation. When the Status LED is off, the device is not powered or did not initialize. Figure 3 on page 10
shows the location of the Status LED.
Caution! Do not disconnect any device from the USB bus while the computer is communicating with
USB-1608G-OEM hardware, or you may lose data and/or your ability to communicate with the
device.
If the Status LED is off
If the Status LED is on but then turns off, the computer has lost communication with the USB-1608G-OEM.
To restore communication, disconnect the USB cable from the computer and then reconnect it. This should
restore communication, and the LED should turn on.
Installing on an Android platform
Many Android devices include a standard A-type USB port to connect to the USB-1608G-OEM. If your device
does not have a USB port, you may need a USB OTG cable in order for your Android device to host a USB
device. Refer to your Android device documentation for more information.

USB-1608G-OEM User's Guide Installing the USB-1608G-OEM
8
Calibrating the hardware
Factory calibration
The Measurement Computing Manufacturing Test department performs the initial factory calibration. Contact
Measurement Computing for details about how to return your device and have it calibrated to the factory
specifications.
Field calibration
The USB-1608G-OEM supports field calibration. Calibrate the device using InstaCal whenever the ambient
temperature changes by more than ±10 °C from the last field calibration.
Firmware updates
Your DAQ device contains firmware that can be updated in the field if required. Firmware is available for
download at www.mccdaq.com/firmware.aspx.We recommend that you check this page periodically to see if an
update to your device firmware is available.

9
Chapter 3
Functional Details
Analog input modes
The USB-1608G-OEM can acquire analog input data in two basic modes – software paced and hardware paced.
Software paced
You can acquire one analog sample at a time in software paced mode. You initiate the A/D conversion with a
software command. The analog value is converted to digital data and returned to the computer. Repeat this
procedure until you have the total number of samples that you want.
The sample rate in software paced mode is system-dependent and can range from 33 S/s to 4000 S/s.
Hardware paced
You can acquire data from up to 16 channels in hardware paced mode. The analog data is continuously
acquired, converted to digital values, and written into the FIFO buffer on the device until you stop the scan. The
FIFO buffer is serviced in blocks as the data is transferred from the FIFO buffer to the computer memory
buffer. You start a hardware-paced scan with either a software command or with an external hardware trigger
event.
The maximum sampling rate in hardware paced mode from one to 16 channels is 250 kS/s aggregate.
Burst mode
When using the onboard pacer, you can enable burst mode for more precise timing between samples. When
burst mode is enabled, each successive channel in a scan is sampled at the maximum A/D rate. This ensures that
samples from each channel are taken as close as possible to the same absolute point in time. When burst mode
is disabled, data is sampled at evenly spaced intervals, allowing maximum settling time and best amplitude
accuracy. Multi-channel scanning with burst mode enabled and disabled is shown in Figure 2.
Figure 2. Multi-channel scan with burst mode enabled and disabled
The burst mode sample period is 4 µs.
You can trigger the acquisition with the external trigger, and control the clock period with the internal or
external A/D pacer clock. Pacing from the external clock always operates with burst mode enabled.

USB-1608G-OEM User's Guide Functional Details
10
Board components
Board components are shown in Figure 3. Note that each screw terminal location is unpopulated.
1 Screw terminal (unpopulated) 5 Pull-up/down jumper W1
2 Header connector W4 6 Status LED (top) and Activity LED (bottom)
3 Header connector W6 7 USB connector
4 Screw terminal (unpopulated)
Figure 3. Board components
USB connector
The USB connector provides +5 V power and communication. No external power supply is required.
LEDs
The device has two LEDs – Status and Activity.
The Status LED turns on when the device is detected and installed on the computer.
The Activity LED blinks when data is transferred, and is off otherwise.
Header connectors
The header connectors provide the following connections:
16 SE (CH0 to CH15) or eight DIFF (CH0H/CH0L to CH7H/CH7L) analog input connections
Eight digital I/O connections (DIO0 to DIO7)
One external clock input (AICKI) and one external clock output (AICKO) for analog inputs
One digital trigger input (TRIG)
Two counter inputs (CTR0, CTR1)
One timer output (TMR)
One power output (+5V)
13 analog ground (AGND) and five digital ground (GND) connections
The differential mode pinout is shown on page 11. The single-ended mode pinout is shown on page 12.

USB-1608G-OEM User's Guide Functional Details
11
Differential mode pinout
Pin Signal Name Description Pin Signal Name Description
1 CH0H Channel 0 HI 29 CH7L Channel 7 LO
2 CH0L Channel 0 LO 30 CH7H Channel 7 HI
3 AGND Analog ground 31 AGND Analog ground
4 CH1H Channel 1 HI 32 CH6L Channel 6 LO
5 CH1L Channel 1 LO 33 CH6H Channel 6 HI
6 AGND Analog ground 34 AGND Analog ground
7 CH2H Channel 2 HI 35 CH5L Channel 5 LO
8 CH2L Channel 2 LO 36 CH5H Channel 5 HI
9 AGND Analog ground 37 AGND Analog ground
10 CH3H Channel 3 HI 38 CH4L Channel 4 LO
11 CH3L Channel 3 LO 39 CH4H Channel 4 HI
12 AGND Analog ground 40 AGND Analog ground
13 NC No connection 41 AGND Analog ground
14 AGND Analog ground 42 AGND Analog ground
15 NC No connection 43 +5V +5V output
16 AGND Analog ground 44 AGND Analog ground
17 NC No connection 45 NC No connection
18 GND Digital ground 46 GND Digital ground
19 DIO0 Digital input/output 0 47 AICKI AI clock input
20 DIO1 Digital input/output 1 48 AICKO AI clock output
21 DIO2 Digital input/output 2 49 NC No connection
22 DIO3 Digital input/output 3 50 NC No connection
23 DIO4 Digital input/output 4 51 TRIG Trigger input
24 DIO5 Digital input/output 5 52 GND Digital ground
25 DIO6 Digital input/output 6 53 CTR1 Counter 1
26 DIO7 Digital input/output 7 54 CTR0 Counter 0
27 GND Digital ground 55 TMR Timer output
28 GND Chassis ground 56 GND Digital ground
Do not connect anything to pins labeled "NC".

USB-1608G-OEM User's Guide Functional Details
12
Single-ended mode pinout
Pin Signal Name Description Pin Signal Name Description
1 CH0 Channel 0 29 CH15 Channel 15
2 CH8 Channel 8 30 CH7 Channel 7
3 AGND Analog ground 31 AGND Analog ground
4 CH1 Channel 1 32 CH14 Channel 14
5 CH9 Channel 9 33 CH6 Channel 6
6 AGND Analog ground 34 AGND Analog ground
7 CH2 Channel 2 35 CH13 Channel 13
8 CH10 Channel 10 36 CH5 Channel 5
9 AGND Analog ground 37 AGND Analog ground
10 CH3 Channel 3 38 CH12 Channel 12
11 CH11 Channel 11 39 CH4 Channel 4
12 AGND Analog ground 40 AGND Analog ground
13 NC No connection 41 AGND Analog ground
14 AGND Analog ground 42 AGND Analog ground
15 NC No connection 43 +5V +5V output
16 AGND Analog ground 44 AGND Analog ground
17 NC No connection 45 NC No connection
18 GND Digital ground 46 GND Digital ground
19 DIO0 Digital input/output 0 47 AICKI AI clock input
20 DIO1 Digital input/output 1 48 AICKO AI clock output
21 DIO2 Digital input/output 2 49 NC No connection
22 DIO3 Digital input/output 3 50 NC No connection
23 DIO4 Digital input/output 4 51 TRIG Trigger input
24 DIO5 Digital input/output 5 52 GND Digital ground
25 DIO6 Digital input/output 6 53 CTR1 Counter 1
26 DIO7 Digital input/output 7 54 CTR0 Counter 0
27 GND Digital ground 55 TMR Timer output
28 GND Chassis ground 56 GND Digital ground
Do not connect anything to pins labeled "NC".
Signal connections
Analog input
You can configure the analog inputs for SE or DIFF mode. The input voltage range is software selectable for
±10 V, ±5 V, ±2 V, or ±1 V.
With SE mode, connect up to 16 inputs to CH0 to CH15. SE mode requires two wires:
Connect one wire to the signal you want to measure (CHx).
Connect one wire to the analog ground reference (AGND).
With DIFF mode, connect up to eight differential inputs to CH0H/CH0L to CH7H/CH7L. DIFF mode requires
two wires plus a ground reference:
Connect one wire to the high/positive signal (CHxH).
Connect one wire to the low/negative signal (CHxL).
Connect one wire to the analog ground reference (AGND).
Floating voltage source
When connecting DIFF voltage inputs to a "floating" voltage source, make sure the DIFF input channel has a
DC return path to ground. To create this path, connect a resistor from each low channel input to an AGND pin.
A value of approximately 100 kΩ can be used for most applications.
Leave unused input channels either floating or tied to an AGND terminal. Source impedances should be kept as
small as possible to avoid settling time and accuracy errors.

USB-1608G-OEM User's Guide Functional Details
13
Figure 4 shows DIFF channels 0-3 connected to a ground path resistor.
Figure 4. DIFF connections with ground path resistor
Channel-Gain queue
The channel-gain queue feature allows you to configure a list of channels, modes, and gains for each scan. The
settings are stored in a channel-gain queue list that is written to local memory on the device.
The channel-gain queue list contains one or more channel numbers, modes, and range settings. You can
configure up to 16 elements. The channels can be listed in any order, and can include duplicate channels for
sampling at different ranges.
An example of a 4-element list is shown in the table below.
Sample channel gain queue list
Element Channel Range Mode
0 CH5 BIP5V SE
1 CH1 BIP10V SE
2 CH15 BIP1V SE
3 CH5 BIP5V SE
Carefully match the gain to the expected voltage range on the associated channel or an over range condition
may occur. Although this condition does not damage the device, it does produce a useless full-scale reading,
and can introduce a long recovery time due to saturation of the input channel.
For more information about analog signal connections
For more information about analog input connections, refer to the Guide to Signal Connections (this document
is available on our web site at www.mccdaq.com/signals/signals.pdf).
External clock I/O
The USB-1608G-OEM provides one external clock input (AICKI) and one external clock output (AICKO) for
analog inputs. You can connect an external clock signal to AICKI and/or AOCKI.
When using an external clock, AICKOoutputs the pulse generated from AICKI.
When using the internal clock, AICKO outputs the ADC scan clock

USB-1608G-OEM User's Guide Functional Details
14
Digital I/O
You can connect up to eight digital I/O lines to DIO0 through DIO7. Each digital channel is individually
configurable for input or output. The digital I/O terminals can detect the state of any TTL-level input. Refer to
the schematic shown in Figure 5.
Figure 5. Schematic showing switch detection by digital channel DIO0
If you set the switch to the +5 V input, DIO0 reads TRUE (1). If you move the switch to GND, DIO0 reads
FALSE (0).
Pull-up/down configuration
Unconnected inputs are pulled low by default to 0 V through 47 kΩ resistors via jumper W1 on the circuit board
(see Figure 6).
Figure 6. W1 jumper location
The pull-up/pull-down voltage is common to all 47 kΩ resistors. Jumper W1 is configured by default for pull-
down. Figure 7 shows the jumper configured for pull-up and pull-down.
Caution! The discharge of static electricity can damage some electronic components. Before touching the
board, ground yourself using a wrist strap or touch the computer chassis or other grounded object
to eliminate any stored static charge.
Figure 7. W1 jumper configurations
For more information about digital signal connections
For general information about digital signal connections and digital I/O techniques, refer to the Guide to Signal
Connections (available on our web site at www.mccdaq.com/signals/signals.pdf).
Trigger input
The TRIG terminal is an external digital trigger input. The trigger mode is software selectable for edge or level
sensitive.
Edge sensitive mode is configurable for rising or falling edge.
Level sensitive mode is configurable for high or low level.
The default setting at power up is edge sensitive, rising edge.

USB-1608G-OEM User's Guide Functional Details
15
Retrigger mode
Retrigger mode lets you set up repetitive analog input or output trigger events. The trigger is automatically re-
armed after it is activated. Use software to set the A/D or D/A trigger count (the number of samples you want
per trigger).
Counter input
The CTR0 and CTR1 terminals are 32-bit event counters that can accept frequency inputs up to 20 MHz. The
internal counter increments when the TTL levels transition from low to high.
Timer output
The TMR terminal is a pulse width modulation (PWM) timer output that can generate a pulse output with a
programmable frequency in the range of 0.0149 Hz to 32 MHz. The timer output parameters are software
selectable. Figure 8 shows the timer output schematic.
Figure 8. Timer output schematic
Power output
The +5V terminal can output up to 10 mA maximum. You can use this terminal to supply power to external
devices or circuitry.
Caution! The +5V terminal is an output. Do not connect to an external power supply or you may damage the
device and possibly the computer.
Ground
The analog ground (AGND) terminals provide a common ground for all analog channels.
The digital ground (GND) terminals provide a common ground for the digital, counter, timer, and clock
channels and the power terminal.

USB-1608G-OEM User's Guide Functional Details
16
Mechanical drawings
Figure 9. USB-1608G-OEM circuit board dimensions

17
Chapter 4
Specifications
All specifications are subject to change without notice.
Typical for 25 °C unless otherwise specified.
Specifications in italic text are guaranteed by design.
Analog input
Table 1. General analog input specifications
Parameter Condition Specification
A/D converter type Successive approximation
ADC resolution 16 bits
Number of channels 8 differential, 16 single-ended
Software-selectable
Input voltage range ±10 V, ±5 V, ±2 V, ±1 V
Software-selectable per channel
Absolute max input voltage CHx relative to AGND ±25 V max (power on)
±15 V max (power off)
Input impedance 1 GΩ (power on)
820 Ω (power off)
Input bias current ±10 nA
Input bandwidth All input ranges,
small signal (–3 dB) 750 kHz
Input capacitance 60 pf
Max working voltage (signal
+ common mode) ±10 V range ±10.2 V max relative to AGND
±5 V range ±10.2 V max relative to AGND
±2 V range ±9.5 V max relative to AGND
±1 V range ±9.0 V max relative to AGND
Common mode rejection ratio (
f
IN = 60 Hz, all input
ranges) 86 dB
Crosstalk Adjacent differential mode
channels, DC to 100 kHz –75 dB
Input coupling DC
Sampling rate 0.0149 Hz to 250 kHz; software-selectable
Trigger source TRIG (see External trigger on page 19)
Sample clock source Internal A/D clock or external A/D clock (AICKI pin)
Burst mode 4 µs
Software-selectable using the internal A/D clock; always
enabled when using the external clock (AICKI pin).
Throughput Software paced 33 to 4000 S/s typ, system dependent
Hardware paced 250 kS/s max
Channel gain queue Up to 16 elements Software-selectable range for each channel
Warm-up time 15 minutes min

USB-1608G-OEM User's Guide Specifications
18
Accuracy
Analog input DC voltage measurement accuracy
Table 2. DC Accuracy components and specifications. All values are (±)
Range Gain error (% of reading) Offset error (µV) INL error (% of range)
Absolute
accuracy at
Full Scale
(µV)
Gain
temperature
coefficient
(% reading/°C)
Offset
temperature
coefficient
(µV/°C)
±10 V 0.024 915 0.0076 4075 0.0014 47
±5 V 0.024 686 0.0076 2266 0.0014 24
±2 V 0.024 336 0.0076 968 0.0014 10
±1 V 0.024 245 0.0076 561 0.0014 5
Noise performance
For the peak-to-peak noise distribution test, a differential input channel is connected to AGND at the input
terminal block, and 32,000 samples are acquired at the maximum rate available at each setting.
Table 3. Noise performance specifications
Range Counts LSBrms
±10 V 6 0.91
±5 V 6 0.91
±2 V 7 1.06
±1 V 9 1.36
Settling time
Settling time is defined as the accuracy that can be expected after one conversion when switching from a
channel with a DC input at one extreme of full scale to another channel with a DC input at the other extreme of
full scale. Both input channels are configured for the same input range.
Table 4. Input settling time specifications in µS, typical
Range 4 µS settling accuracy
(% FSR) 6 µS settling accuracy (% FSR) ±10 µS settling accuracy (% FSR)
±10 V 0.0061 0.0031 0.0015
±5 V 0.0061 0.0031 0.0015
±2 V 0.0061 0.0031 0.0015
±1 V 0.0061 0.0031 0.0015
Analog input calibration
Table 5. Analog input/output calibration specifications
Parameter Specification
Recommended warm-up time 15 minutes min
Calibration method Self-calibration (firmware)
Calibration interval 1 year (factory calibration)
AI calibration reference +5 V, ±2.5 mV max. Actual measured values stored in EEPROM.
Tempco: 5 ppm/°C max
Long term stability: 15 ppm/1000 hours

USB-1608G-OEM User's Guide Specifications
19
Digital input/output
Table 6. Digital input/output specifications
Parameter Specification
Digital type CMOS
Number of I/O 8
Configuration Each bit may be configured as input (power on default) or output
Pull-up configuration The port has 47 kΩ resistors configurable as pull-ups or pull-downs (default) via
internal jumper (W1).
Digital I/O transfer rate
(system-paced) 33 to 8000 port reads/writes or single bit reads/writes per second typ, system dependent.
Input high voltage 2.0 V min
5.5 V absolute max
Input low voltage 0.8 V max
–0.5 V absolute min
0 V recommended min
Output high voltage 4.4 V min (IOH = –50 µA)
3.76 V min (IOH = –2.5 mA)
Output low voltage 0.1 V max (IOL = 50 µA)
0.44 V max (IOL = 2.5 mA)
Output current ±2.5 mA max
External trigger
Table 7. External trigger specifications
Parameter Specification
Trigger source TRIG input
Trigger mode Software programmable for edge or level sensitive, rising or falling edge, high or low
level. Power on default is edge sensitive, rising edge.
Trigger latency 1 µs + 1 clock cycle max
Trigger pulse width 100 ns min
Input type Schmitt trigger, 33 Ω series resistor and 49.9 kΩ pull-down to ground
Schmitt trigger hysteresis 0.4 V to 1.2 V
Input high voltage 2.2 V min
5.5 V absolute max
Input low voltage 1.5 V max
–0.5 V absolute min
0 V recommended min

USB-1608G-OEM User's Guide Specifications
20
External clock input/output
Table 8. External clock I/O specifications
Parameter Specification
Terminal names AICKI, AICKO
Terminal types AICKI: Input, active on rising edge
AICKO: Output, power on default is 0 V, active on rising edge
Terminal descriptions AICKI: Receives sampling clock from external source
AICKO: Outputs the internal sampling clock (D/A or A/D clock) or the pulse generated
from AICKI when in external clock mode.
Input clock rate 250 kHz max
Clock pulse width AICKI: 400 ns min
AICKO: 400 ns min
Input type Schmitt trigger, 33 Ω series resistor, 47 kΩ pull-down to ground
Schmitt trigger hysteresis 0.4 V to 1.2 V
Input high voltage 2.2 V min
5.5 V absolute max
Input low voltage 1.5 V max
–0.5 V absolute min
0 V recommended min
Output high voltage 4.4 V min (IOH = –50 µA)
3.76 V min (IOH = –2.5 mA)
Output low voltage 0.1 V max (IOL = 50 µA)
0.44 V max (IOL = 2.5 mA)
Output current ±2.5 mA max
Counter
Table 9. Counter specifications
Parameter Specification
Terminal names CTR0, CTR1
Number of channels 2 channels
Resolution 32-bit
Counter type Event counter
Input type Schmitt trigger, 33 Ω series resistor, 47 kΩ pull-down to ground
Input source CTR0 (pin 52)
CTR1 (pin 51)
Counter read/writes rates
(software paced) 33 to 8000 reads/writes per second typ, system dependent
Input high voltage 2.2 V min, 5.5 V max
Input low voltage 1.5 V max, –0.5 V min
Schmitt trigger hysteresis 0.4 V min, 1.2 V max
Input frequency 20 MHz, max
High pulse width 25 ns, min
Low pulse width 25 ns, min