DS2401X1 [MAXIM]
Memory Circuit, 64X1, CMOS, PBGA2, CSP-2;
| 型号： | DS2401X1 |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Memory Circuit, 64X1, CMOS, PBGA2, CSP-2 内存集成电路 |
| 文件： | 总11页 (文件大小：219K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-5860; Rev 12/16
DS2401
Silicon Serial Number
BENEFITS AND FEATURES
• Guaranteed Unique 64-Bit ROM ID Chip for
Absolute Traceability
PIN CONFIGURATIONS
TO-92
TSOC
DS2401
o Unique, Factory-Lasered and Tested
64-Bit Registration Number (8-Bit Family
Code +48-Bit Serial Number + 8-Bit CRC
Tester)
TOP VIEW
o 8-Bit Family Code Specifies DS2401
Communications Requirements to Reader
• Minimalist 1-Wire® Interface Lowers Cost
and Interface Complexity
o Multiple DS2401 Devices Can Reside on
a Common 1-Wire Net
o Built-In Multidrop Controller Ensures
Compatibility with Other 1-Wire Net
Products
1
2
3
o Reduces Control, Address, Data, and
Power to a Single Pin and Communicates
at Up to 16.3kbps
1 2 3
TOP VIEW
o Presence Pulse Acknowledges When the
Reader First Applies Voltage
o Low-Cost TO-92, SOT-223, and TSOC
Surface-Mount Packages
o TO-92 Tape-and-Reel Version with Leads
Bent to 100-mil Spacing (Default) or with
Straight Leads (DS2401-SL)
BOTTOM VIEW
01rrd
Flip Chip, Top View
with Laser Mark,
Contacts Not Visible.
“rrd” = Revision/Date
1
2
DS2401
TOP VIEW
. Wide Voltage and Temperature Operating
Ranges Enables Robust System Performance
o Extended 2.8V to 6.0V Range
o Zero Standby Power Required
o -40°C to +85°C Industrial Temperature
Range
+
A
1
1
2
2
B
WLP
APPLICATIONS
PCB Identification
Network Node ID
PIN DESCRIPTIONS
PIN
NAME
SOT-
223
FLIP-
CHIP
TO-92
TSOC
WLP
Equipment Registration
DATA
(DQ)
GROUND
N.C. (No
Connect)
2
1
3
2
1, 4
3
2
1
1
2
A1, B1
A2, B2
—
3–6
—
1-Wire is a registered trademark of Maxim Integrated Products, Inc.
1 of 11
DS2401
ORDERING INFORMATION
PART
DS2401+
DS2401+T&R
DS2401-SL+T&R
DS2401P+
DS2401P+T&R
DS2401Z+
DS2401Z+T&R
DS2401X1-S#T
DS2401X-S+T
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
3 TO-92
3 TO-92 (formed leads)
3 TO-92 (straight leads)
6 TSOC
6 TSOC
4 SOT-223
4 SOT-223
2 Flip Chip (2.5k pieces)
4 WLP
+Denotes a lead(Pb)-free/RoHS-compliant package.
T&R/T = Tape and reel.
SL = Straight leads.
#Denotes a RoHS-compliant device that may include lead that is exempt under the RoHS requirements.
DESCRIPTION
The DS2401 enhanced silicon serial number is a low-cost, electronic registration number that provides an
absolutely unique identity which can be determined with a minimal electronic interface (typically, a
single port pin of a microcontroller). The DS2401 consists of a factory-lasered, 64-bit ROM that includes
a unique 48-bit serial number, an 8-bit CRC, and an 8-bit Family Code (01h). Data is transferred serially
via the 1-Wire protocol that requires only a single data lead and a ground return. Power for reading and
writing the device is derived from the data line itself with no need for an external power source. The
DS2401 is an upgrade to the DS2400. The DS2401 is fully reverse-compatible with the DS2400 but
provides the additional multi-drop capability that enables many devices to reside on a single data line.
The familiar TO-92, SOT-223 or TSOC package provides a compact enclosure that allows standard
assembly equipment to handle the device easily.
OPERATION
The DS2401’s internal ROM is accessed via a single data line. The 48-bit serial number, 8-bit family
code and 8-bit CRC are retrieved using the Maxim 1-Wire protocol. This protocol defines bus
transactions in terms of the bus state during specified time slots that are initiated on the falling edge of
sync pulses from the bus master. All data is read and written least significant bit first.
1-Wire BUS SYSTEM
The 1-Wire bus is a system which has a single bus master system and one or more slaves. In all instances,
the DS2401 is a slave device. The bus master is typically a microcontroller. The discussion of this bus
system is broken down into three topics: hardware configuration, transaction sequence, and 1-Wire
signaling (signal type and timing).
Hardware Configuration
The 1-Wire bus has only a single line by definition; it is important that each device on the bus be able to
drive it at the appropriate time. To facilitate this, each device attached to the 1-Wire bus must have an
open-drain connection or 3-state outputs. The DS2401 is an open-drain part with an internal circuit
equivalent to that shown in Figure 2. The bus master can be the same equivalent circuit. If a bidirectional
pin is not available, separate output and input pins can be tied together. The bus master requires a pullup
resistor at the master end of the bus, with the bus master circuit equivalent to the one shown in Figure 3.
The value of the pullup resistor should be approximately 5kΩ for short line lengths. A multidrop bus
consists of a 1-Wire bus with multiple slaves attached. The 1-Wire bus has a maximum data rate of
16.3kbits per second.
2 of 11
DS2401
The idle state for the 1-Wire bus is high. If, for any reason, a transaction needs to be suspended, the bus
MUST be left in the idle state if the transaction is to resume. If this does not occur and the bus is left low
for more than 120µs, one or more of the devices on the bus may be reset.
DS2401 MEMORY MAP Figure 1
8-Bit CRC Code
48-Bit Serial Number
8-Bit Family Code (01h)
LSB MSB LSB
MSB
LSB MSB
DS2401 EQUIVALENT CIRCUIT Figure 2
BUS MASTER CIRCUIT Figure 3
A) Open Drain
VPUP
See note
To data connection
of DS2401
B) Standard TTL
VPUP
See note
To data connection
of DS2401
Note:
Depending on the 1-Wire communication speed and the bus load characteristics, the optimal pullup
resistor (RPU) value will be in the 1.5kΩ to 5kΩ range.
3 of 11
DS2401
TRANSACTION SEQUENCE
The sequence for accessing the DS2401 via the 1-Wire port is as follows:
. Initialization
. ROM Function Command
. Read Data
INITIALIZATION
All transactions on the 1-Wire bus begin with an initialization sequence. The initialization sequence
consists of a reset pulse transmitted by the bus master followed by a Presence Pulse(s) transmitted by the
slave(s).
The Presence Pulse lets the bus master know that the DS2401 is on the bus and is ready to operate. For
more details, see the 1-Wire Signaling section.
ROM FUNCTION COMMANDS
Once the bus master has detected a presence, it can issue one of the four ROM function commands. All
ROM function commands are 8 bits long. A list of these commands follows (refer to flowchart in Figure
4).
Read ROM [33h] or [0Fh]
This command allows the bus master to read the DS2401’s 8-bit family code, unique 48-bit serial
number, and 8-bit CRC. This command can only be used if there is a single DS2401 on the bus. If more
than one slave is present on the bus, a data collision will occur when all slaves try to transmit at the same
time (open drain will produce a wired-AND result). The DS2401 Read ROM function will occur with a
command byte of either 33h or 0Fh in order to ensure compatibility with the DS2400, which will only
respond to a 0Fh command word with its 64-bit ROM data.
Match ROM [55h] / Skip ROM [CCh]
The complete 1-Wire protocol for all Maxim iButtons® contains a Match ROM and a Skip ROM
command. Since the DS2401 contains only the 64-bit ROM with no additional data fields, the Match
ROM and Skip ROM are not applicable and will cause no further activity on the 1-Wire bus if executed.
The DS2401 does not interfere with other 1-Wire parts on a multidrop bus that do respond to a Match
ROM or Skip ROM (for example, a DS2401 and DS1994 on the same bus).
Search ROM [F0h]
When a system is initially brought up, the bus master might not know the number of devices on the
1-Wire bus or their 64-bit ROM codes. The search ROM command allows the bus master to use a process
of elimination to identify the 64-bit ROM codes of all slave devices on the bus. The ROM search process
is the repetition of a simple 3-step routine: read a bit, read the complement of the bit, then write the
desired value of that bit. The bus master performs this simple 3-step routine on each bit of the ROM.
After one complete pass, the bus master knows the contents of the ROM in one device. The remaining
number of devices and their ROM codes may be identified by additional passes. Refer to Application
Note 187: 1-Wire Search Algorithm for a comprehensive discussion of a ROM search, including an actual
example.
iButton is a registered trademark of Maxim Integrated Products, Inc.
4 of 11
DS2401
1-Wire SIGNALING
The DS2401 requires a strict protocol 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 DS2401 is shown in Figure 5.
A reset pulse followed by a Presence Pulse indicates the DS2401 is ready to send or receive data given
the correct ROM command.
The bus master transmits (TX ) a reset pulse (tRSTL , minimum 480µs). The bus master then releases the
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 DS2401 waits (tPDH, 15-60µs) and then transmits the
Presence Pulse (tPDL, 60-240µs). The 1-Wire bus requires a pullup resistor range of 1.5kΩ to 5kΩ,
depending on bus load characteristics.
READ/WRITE TIME SLOTS
The definitions of write and read time slots are illustrated in Figure 6. All time slots are initiated by the
master driving the data line low. The falling edge of the data line synchronizes the DS2401 to the master
by triggering a delay circuit in the DS2401. During write time slots, the delay circuit determines when the
DS2401 will sample the data line. For a read data time slot, if a “0” is to be transmitted, the delay circuit
determines how long the DS2401 will hold the data line low overriding the “1” generated by the master.
If the data bit is a 1, the DS2401 will leave the read data time slot unchanged.
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DS2401
ROM FUNCTIONS FLOW CHART Figure 4
6 of 11
DS2401
INITIALIZATION PROCEDURE “RESET AND PRESENCE PULSES” Figure 5
480µs ≤ tRSTL < ∞ *
480µs ≤ tRSTH < ∞ (includes recovery time)
15µs ≤ tPDH < 60µs
RESISTOR
MASTER
DS2401
60µs ≤ tPDL < 240µs
∗ In order not to mask interrupt signaling by other devices on the 1-Wire bus, tRSTL + tR should always
be less than 960µs.
READ/WRITE TIMING DIAGRAM Figure 6
Write-One Time Slot
60µs ≤ tSLOT < 120µs
1µs ≤ tLOW1 < 15µs
1µs ≤ tREC < ∞
RESISTOR
MASTER
7 of 11
DS2401
READ/WRITE TIMING DIAGRAM (cont’d) Figure 6
Write-zero Time Slot
60µs ≤ tLOW0 < tSLOT < 120µs
1µs ≤ tREC < ∞
Read-data Time Slot
60µs ≤ tSLOT < 120µs
1µs ≤ tLOWR < 15µs
0 ≤ tRELEASE < 45µs
1µs ≤ tREC < ∞
tRDV = 15µs
RESISTOR
MASTER
DS2401
tSU < 1µs
CRC GENERATION
To validate the data transmitted from the DS2401, the bus master may generate a CRC value from the
data as it is received. This generated value is compared to the value stored in the last 8 bits of the
DS2401. If the two CRC values match, the transmission is error-free.
The equivalent polynomial function of this CRC is: CRC = x8 + x5 + x4 + 1. Additional information about
the Maxim 1-Wire CRC is available in Application Note 27.
CUSTOM DS2401
Customization of a portion of the unique 48-bit serial number by the customer is available. Maxim will
register and assign a specific customer ID in the 12 most significant bits of the 48-bit field. The next most
significant bits are selectable by the customer as a starting value, and the least significant bits are non-
selectable and will be automatically incremented by one. Certain quantities and conditions apply for these
custom parts. Contact your Maxim sales representative for more information.
8 of 11
DS2401
ABSOLUTE MAXIMUM RATINGS
Voltage Range on Any Pin Relative to Ground
Operating Temperature Range
Storage Temperature Range
Lead Temperature (TO-92, TSOC, SOT-223 only; soldering, 10s)
Soldering Temperature (reflow)
TO-92
-0.5V to +7.0V
-40°C to +85°C
-55°C to +125°C
+300°C
+250°C
+260°C
+240°C
TSOC, SOT-223, WLP
Flip Chip
This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation sections of this
specification is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability.
DC ELECTRICAL CHARACTERISTICS
(TA = -40°C to +85°C, unless otherwise noted.)
PARAMETER
Pullup Voltage
Logic 1
SYMBOL
VPUP
VIH
MIN
2.8
2.2
TYP
MAX
6.0
UNITS NOTES
V
V
V
2
1, 6
1
Logic 0
VIL
VOL
IL
QOP
-0.3
+0.3
0.4
Output Logic-Low at 4mA
Input Load Current
Operating Charge
V
1
5
3
7, 8
µA
nC
30
CAPACITANCE
(TA = +25°C, unless otherwise noted.)
PARAMETER
SYMBOL
CIN/OUT
MIN
TYP
TYP
MAX
800
UNITS NOTES
pF
I/O (1-Wire)
9
AC ELECTRICAL CHARACTERISTICS
(TA = -40°C to +85°C, unless otherwise noted.)
PARAMETER
Time Slot
Write 1 Low Time
Write 0 Low Time
Read Data Valid
Release Time
Read Data Setup
Recovery Time
Reset Time High
Reset Time Low
Presence Detect High
Presence Detect Low
SYMBOL
tSLOT
tLOW1
tLOW0
tRDV
tRELEASE
tSU
tREC
MIN
60
1
MAX
120
15
UNITS NOTES
µs
12
11
5
µs
µs
µs
µs
µs
µs
µs
µs
µs
µs
60
120
15
15
0
45
1
1
tRSTH
tRSTL
tPDH
480
480
15
4
10
960
60
240
tPDL
60
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DS2401
NOTES:
1) All voltages are referenced to ground.
2) VPUP = external pullup voltage.
3) Input load is to ground.
4) An additional reset or communication sequence cannot begin until the reset high time has expired.
5) Read data setup time refers to the time the host must pull the 1-Wire bus low to read a bit. Data is
guaranteed to be valid within 1µs of this falling edge and will remain valid for 14µs minimum (15µs
total from falling edge on 1-Wire bus).
6) VIH is a function of the external pullup resistor and VPUP
.
7) 30 nanocoulombs per 72 time slots at 5.0V.
8) At VPUP= 5.0V with a 5kΩ pullup to VPUP and a maximum time slot of 120µs.
9) Capacitance on the I/O pin could be 800pF when power is first applied. If a 5kΩ resistor is used to
pullup the I/O line to VPUP, 5µs after power has been applied the parasite capacitance will not affect
normal communications.
10) The reset low time (tRSTL) should be restricted to a maximum of 960µs, to allow interrupt signaling,
otherwise it could mask or conceal interrupt pulses if this device is used in parallel with a DS2404 or
DS1994.
11) The optimal sampling point for the master is as close as possible to the end time of the tRDV period
without exceeding tRDV. For the case of a Read-One Time slot, this maximizes the amount of time for
the pullup resistor to recover to a high level. For a Read-Zero Time slot, it ensures that a read will
occur before the fastest 1-Wire device(s) releases the line.
12) The duration of the low pulse sent by the master should be a minimum of 1μs with a maximum value
as short as possible to allow time for the pullup resistor to recover the line to a high level before the
1-Wire device samples in the case of a Write-One Time or before the master samples in the case of a
Read-One Time.
PACKAGE INFORMATION
For the latest package outline information and land patterns (footprints), go to www.maxim-ic.com/packages. Note that a “+”,
“#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the
drawing pertains to the package regardless of RoHS status.
PACKAGE TYPE
PACKAGE CODE
OUTLINE NO.
21-0248
LAND PATTERN NO.
3 TO-92
(straight leads)
3 TO-92
Q3+1
—
Q3+4
—
21-0250
(formed leads)
6 TSOC
4 SOT-223
2 Flip Chip
D6+1
K3+1
21-0382
21-0264
21-0378
90-0321
—
BF211#1
21-0378
Refer to
Application Note 1891
4 WLP
N40B1+1
21-0605
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DS2401
REVISION HISTORY
REVISION
PAGES
CHANGED
DESCRIPTION
DATE
Changed MicroLAN to 1-Wire Net; updated ordering information for
tape and reel
Changed soldering temperature from 260°C for 10 seconds to See J-STD-
020A Specification
Below Figure 3, added a note on the optimal RPUP range; added a similar
note before the Read/Write Time Slots section
Added notes 11 to 13 to the EC table
1
040601
022202
9
3, 6
9, 10
1, 2
Added flip chip package; added lead-free ordering information
References to the Book of iButton Standards replaced with references to
corresponding application notes
VILMAX changed from 0.8V to 0.3V, EC table note 11 deleted
Deleted standard (Pb) parts from ordering information; changed flip chip
part number from DS2401X1 to DS2401X1-S#T
Deleted VOH from the EC table; moved VPUP from the EC table header
into the EC table; changed soldering temperature from J-STD-020A
reference to explicit package specific numbers
122106
5/11
Various
9, 10
2
9
Added Package Information and Revision History sections
Revised Benefits and Features section
10, 11
1
3/15
Added WLP package to Pin Configurations, Pin Descriptions, Ordering
Information, Absolute Maximum Ratings, and Package Information
sections
12/16
1, 2, 9, 10
11 of 11
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim
reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 160 Rio Robles, San Jose, CA 94134 408-601-1000
© 2016 Maxim Integrated Products
Maxim is a registered trademark of Maxim Integrated Products, Inc.
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