User's Manual

July 23, 2002 4-19
CreataLink2 XT Hardware Integrator’s Guide Hardware Integration
Power Management
Power Supply Circuit Details
You are responsible for supplying power to the data transceiver. Certain
specifications must be met to ensure proper operation.
The data transceiver accepts the following range of power supply voltages applied
to pin 1 (Supply) of the 22-pin connector:
NUF3902: 5 Vdc to 12 Vdc
NUF8006: 5 Vdc to 16 Vdc
The following additional specifications must also be met (see Table 4-5, Figure 4-1,
and Figure 4-2).
The voltage range described in Table 4-5 is available in the integrator’s host system
in most applications. If the voltage is not available, use a regulator to ensure that
the supply voltage is 5 Vdc. Select the regulator based on the input voltage and
current-sourcing capabilities.
Switching regulators are efficient, but they introduce unwanted noise into the
system. If you use a switching regulator, the filtered output should meet the supply
ripple specification.
Linear regulators supply a clean dc voltage but are inefficient. It is your choice
whether to use a linear or switching regulator.
Shutdown Procedures
If the host application turns the data transceiver off for any period of time,
SmartSynch, Inc. recommends that you send a reverse path message to the
application host or server indicating that the data transceiver is no longer available.
This prevents a failed message from being sent to a data transceiver that is powered
down. At power-up, send a message to the application server indicating that the
data transceiver is ready to receive messages.
Table 4-5. Power Supply Specifications
Item NUF3902 NUF8006
Supply ripple–Vpp 100 mV peak-to-peak maximum up to 5 MHz
Open circuit voltage–Voc 12 Vdc maximum 16 Vdc maximum
Rise time 500 µs or less (from 80 mA to 1400 mA)
Minimum voltage and current 5Vdc at 1.4A (without driven output current)
➧
A linear regulator is easier to integrate because of the quiet output.