DS2480B Maxim Integrated Products, DS2480B Datasheet - Page 24

• Manufacturer Part Number: DS2480B
• Description: IC LINE DRVR W/SENSOR 1-W 8-SOIC
• Manufacturer: Maxim Integrated Products
• Type: Line Driver, Transmitterr

Specifications of DS2480B

• Number Of Drivers/receivers: 1/0
• Protocol: RS232
• Voltage - Supply: 4.5 V ~ 5.5 V
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

HARDWARE APPLICATION EXAMPLES
This section discusses five typical application scenarios. The DS2480B can be configured for EPROM
programming as well as for 5V operation only.
OUTPUT FILTERING
As described in the CONTROLLED EDGES section, the DS2480B employs an active pullup on the rising
edges of the 1-Wire waveform.
Excessive noise on the 1-Wire line in the region of the pullup trip voltage, V
undesirable trip of the active pullup, which can disrupt 1-Wire communication. External R-C filtering as
shown in Figure 10 should be added to all DS2480B configurations with the exception of those that
perform EPROM programming or that are operating in Overdrive mode.
For EPROM programming configurations the R-C filter cannot be used due to the voltage drop that will
develop across the 100Ω resistor during programming.
Figure 10. R-C FILTERING
To protect the 1-Wire port of the DS2480B from electrostatic discharge it is recommended to use a low-
capacitance ESD protection diode, such as the DS950x devices. For 5V operation a single device is
sufficient. For EPROM programming two DS950x devices must be connected in series to achieve a high
enough breakdown voltage.
Figures 11a-c are examples of connecting the DS2480B directly to a UART or RS232C interface. The
circuit becomes more complex if a 1-Wire bus is to be interfaced to a port that provides and expects
inverted signals, but does not necessarily meet the RS232C (±12V) standard (Figure 11b).
5 V
5V Operation Only
VPP
RXD
TXD
DS2480
GND
VDD
POL
1-W
Return
1-Wire Bus
24 of 31
100 ohms
470 pf
DS9503
IAPTO,
can cause an