User's Manual
Table Of Contents
- Foreword
- Important Safety Information
- Contents
- About this Document
- Related Publications
- Product Description
- Features
- Specifications
- Air Interface
- Product Functionality
- Contents
- Integration Goal and Objectives
- Customer Problem Isolation
- Wireline and Wireless Communications
- Design Tips for Serviceability
- Environmental Issues
- Regulatory Requirements
- Contents
- Power Supply
- Host Interface
- Power Management
- Antenna Systems
- Hardware Recommendations
- Battery Selection Criteria
- Contents
- Hardware Integration
- Application Software
- Final Assembly
- Installation
- Troubleshooting
- End User Problem Resolution
- Service Depot Repair
- Contents
- Accessories and Options
- Abbreviations and Acronyms
- Desense Overview
- Desense Measurement Techniques
- Preparing the Device Under Test
- Performance Goals
- Methods of Controlling Emissions
- Antenna
- Summary
- FLEX Application Protocol Licensing
- Licensing
July 23, 2002 4-5
CreataLink2 XT Hardware Integrator’s Guide Hardware Integration
Host Interface
High Voltage Input Circuit
There are no requirements for external components, unless the input voltage is to
be higher than 12V for NUF3902 and 16V for NUF8006. If this is the case, perform
external signal conditioning that will limit the voltage to a maximum of 12V for
NUF3902 and 16V for NUF8006. Logic ones on the input pin are read as logic ones
by the host processor, i.e. normal logic convention.
Over-voltage protection is not provided. ESD/transient protection is provided;
however, exceeding the specified maximum input voltages for long durations will
render the circuit nonfunctional.
The input voltage must be equal to or less than the supply voltage provided to
pin 1 of the 22-pin connector.
Open Collector Output Circuit
To size the pullup resistor, follow the steps detailed in“Resistor Sizing Example” on
page 4-9. The maximum pull-up voltage for this circuit is specified as 12V for
NUF3902 and 16V for NUF8006.
Circuit Specifications/Limitations
The open collector circuit enables the CreataLink2 XT device to interface to systems
with higher voltages than it can support itself. This feature alone provides great
flexibility in interface circuit design. However, this circuit has some limitations that
you must recognize when you design. For example, the pull-up resistor must be
sized according to load size and desired output high voltage.
Current Sink Limitations
The CreataLink2 XT device has a maximum current sink capability of 25 mA when
the output is in the low state. To exceed this current could cause the circuit to break
down, thus causing a potential failure. In addition, this could cause damage to the
host processor, rendering the product non-functional. There is no sink current in
the high state.
To ensure that this maximum sink current is not exceeded, you must know the
circuit pull-up voltage, V
PU
, specification for the circuit. The pull-up voltage
determines the lower-bound for the pull-up resistor, according to the following
relation:
R
PUmin
= (V
PU
)/(.025)
Thus, for a system with V
PU
= 12V, the minimum value for R
Pumin
would be 480
ohms; for a system with V
PU
= 16V, the minimum value for R
Pumin
would be 640
ohms.
G
A pull-up resistor must be placed between the pull-up voltage and the connection to
the CreataLink2 XT device. Otherwise, the circuit will fail.