DS2480B+ Maxim Integrated Products, DS2480B+ Datasheet - Page 18

• 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: Lead free / RoHS Compliant

DS2480B
PULSE WAVEFORMS, DISARMED
The Pulse command can be used to generate a strong pullup to 5V and a 12V programming pulse,
respectively. The duration of the pulse is predefined if the parameter value code of parameter 010
(Programming Pulse Duration) has a value from 000 to 110, and parameter 011 (Strong Pullup Duration)
has a value from 000 to 101 (see Table 4). Figures 7a and 7b show the timing of a pulse with predefined
duration, which should be considered the normal case. If infinite duration is chosen (parameter value code
111), the host must terminate the Pulse command, as shown in Figures 7c and 7d. All versions of Figure 7
assume that bit 1 of the pulse command is 0, i.e., disarmed mode. See the Communication Commands:
Pulse section for more details on possibilities of the Pulse command.
Figure 7a. STRONG PULLUP TO 5V, PREDEFINED DURATION
The processing of a pulse command is essentially the same, regardless if a strong pullup or a
programming pulse is requested. At t
the host starts sending the pulse command byte. At t
the DS2480B
1
2
has received the command and immediately generates the pulse. The pulse ends at t
and the DS2480B
3
sends out the command response byte to inform the host that the command is completed. The idle time
between t
and t
is determined by the time to transmit the command byte at the selected baud rate. The
1
2
idle time between t
and t
is comprised of the time to transmit the response byte, plus the response time
3
4
of the host plus the time to transmit the command and/or data to generate the next time slot.
Figure 7b. 12V PROGRAMMING PULSE, PREDEFINED DURATION
A correct programming pulse can only be generated if the 12V programming voltage is available at the
V
pin of the DS2480B. The rising and falling edges of the programming pulse are actively controlled by
PP
DS2480B. The slew rate is approximately 14V/µs and meets the requirements of 1-Wire EPROM
devices.
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