DS2405Z/T&R Maxim Integrated Products, DS2405Z/T&R Datasheet - Page 11

• Manufacturer Part Number: DS2405Z/T&R
• Description: IC SWITCH ADDRESS NCH O-D SOT223
• Manufacturer: Maxim Integrated Products

Specifications of DS2405Z/T&R

• Interface: 1-Wire
• Voltage - Supply: 2.8 V ~ 6 V
• Package / Case: SOT-223 (3 leads + Tab), SC-73, TO-261
• Mounting Type: Surface Mount
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Applications: -

Skip ROM [CCh]
The complete 1-Wire protocol for all Dallas Semiconductor iButtons contains a Skip ROM command.
Since the DS2405 contains only the 64-bit ROM with no additional data fields, the Skip ROM is not
applicable and will cause no further activity on the 1-Wire bus if executed. The DS2405 does not interfere
with other 1-Wire parts on a multidrop bus that do respond to a Skip ROM (for example, a DS2405 and
DS1994 on the same bus).
1-WIRE SIGNALING
The DS2405 requires strict protocols to ensure data integrity. The protocol consists of four types of
signaling on one line: reset sequence with Reset Pulse and Presence Pulse, write 0, write 1 and read data.
All these signals except Presence Pulse are initiated by the bus master.
The initialization sequence required to begin any communication with the DS2405 is shown in Figure 5.
A Reset Pulse followed by a Presence Pulse indicates the DS2405 is ready to send or receive data given
the correct ROM command.
The bus master transmits (TX) a Reset Pulse (t
line and goes into receive mode (RX). The 1-Wire bus is pulled to a high state via the 5kΩ pullup resistor.
After detecting the rising edge on the data pin, the DS2405 waits (t
Presence Pulse (t
∗ In order not to mask interrupt signaling by other devices on the 1-Wire bus, t
INITIALIZATION PROCEDURE “RESET AND PRESENCE PULSES” Figure 5
be less than 960μs.
PDL
RESISTOR
MASTER
DS2405
, 60-240μs).
480μs ≤ t
480μs ≤ t
15μs ≤ t
60μs ≤ t
PDH
PDL
RSTL
RSTH
RSTL
< 240μs
< 60μs
11 of 15
< ∞*
< ∞ (includes recovery time)
, minimum 480μs). The bus master then releases the
PDH
, 15-60μs) and then transmits the
RSTL
+ t
R
should always