DS2480B Maxim Integrated Products, DS2480B Datasheet - Page 19

• 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

DS2480B
For EPROM programming, only a single slave device should be connected to the 1-Wire bus and the
cable must to be short, not to exceed a few meters. One should not attempt generating a programming
pulse with a non-EPROM device on the bus; this may damage the device as well as the DS2480B.
Certain applications may require a duration for a strong pullup or programming pulse that cannot be
realized using one of the predefined values. Selecting infinite duration allows the host to generate pulses
of any length. As a consequence, however, the host becomes responsible to actively control the duration
of the pulse. Failing to do so may require a power-on reset or master reset cycle of the DS2480B. For this
reason, infinite duration should only be used if absolutely necessary.
The time to end a pulse of infinite duration strongly depends on the baud rate of the communication
between host and DS2480B. Neglecting the response time of the host, the minimum pulse durations are:
86.8µs at 115.2kbps, 173.6µs at 57.6kbps, 520µs at 19.2kbps, and 1.04ms at 9.6kbps.
Figure 7c. STRONG PULLUP TO 5V, INFINITE DURATION
As before, processing the command is essentially the same, regardless if it is for a strong pullup or a
programming pulse. At t
the host starts sending the Pulse command byte. At t
the DS2480B has
1
2
received the command and immediately activates the strong pullup or switches in the 12V programming
voltage. To end the pulse, the DS2480B must receive a Termination command, code F1h, which occurs at
t
. The Termination command does not generate a response byte. The DS2480B will immediately end the
3
pulse and send out the response byte of the pulse command. The idle time between t
and t
is determined
1
2
by the time to transmit the command byte at the selected baud rate. The idle time between t
and t
is
3
4
comprised of the time to transmit the pulse response byte, plus the response time of the host plus the time
to transmit the command and/or data to generate the next time slot.
Figure 7d. 12V PROGRAMMING PULSE, INFINITE DURATION
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