DS1922T-F5 MAXIM [Maxim Integrated Products], DS1922T-F5 Datasheet - Page 12

• Manufacturer Part Number: DS1922T-F5
• Description: Temperature Logger iButton With 8kB Datalog Memory
• Manufacturer: MAXIM [Maxim Integrated Products]

COMMON iBUTTON FEATURES
EXAMPLES OF ACCESSORIES
DS9096P
DS9101
DS9093RA
DS9093A
DS9092
APPLICATION
The DS1922L is an ideal device to monitor for extended periods of time the temperature of any object it is attached
to or shipped with, such as fresh produce, medical drugs and supplies and for use in refrigerators and freezers.
With its shifted temperature range, the DS1922T is suited to monitor processes that require temperatures close to
the boiling point of water, such as pasteurization of food items. Note that the initial sealing level of DS1922L/T
achieves IP56. Aging and use conditions can degrade the integrity of the seal over time, so for applications with
significant exposure to liquids, sprays, or other similar environments, it is recommended to place the Thermochron
in the DS9107
www.maxim-ic.com/AN4126). Software for setup and data retrieval through the 1-Wire interface is available for free
download from the iButton website (www.ibutton.com). This software also includes drivers for the serial and USB
port of a PC, and routines to access the general-purpose memory for storing application- or equipment-specific
data files.
OVERVIEW
The block diagram in Figure 1 shows the relationships between the major control and memory sections of the
DS1922L/T. The device has six main data components: 1) 64-bit lasered ROM, 2) 256-bit scratchpad, 3) 512-byte
general-purpose SRAM, 4) two 256-bit register pages of timekeeping, control, status, and counter registers and
passwords, 5) 64 bytes of calibration memory, and 6) 8192 bytes of data-logging memory. Except for the ROM and
the scratchpad, all other memory is arranged in a single linear address space. The data-logging memory, counter
registers, and several other registers are read-only for the user. Both register pages are write-protected while the
device is programmed for a mission. The password registers, one for a read password and another one for a
read/write password can only be written, never read.
Figure 1 shows the hierarchical structure of the 1-Wire protocol. The bus master must first provide one of the eight
ROM function commands: 1) Read ROM, 2) Match ROM, 3) Search ROM, 4) Conditional Search ROM, 5) Skip
ROM, 6) Overdrive-Skip ROM, 7) Overdrive-Match ROM or 8) Resume. Upon completion of an Overdrive ROM
command byte executed at standard speed, the device will enter Overdrive mode, where all subsequent
communication occurs at a higher speed. The protocol required for these ROM function commands is described in
Figure 11. After a ROM function command is successfully executed, the memory and control functions become
accessible and the master may provide any one of the nine available commands. The protocol for these memory
and control function commands is described in Figure 9. All data is read and written least significant bit first.
Thermochron is a registered trademark of Dallas Semiconductor, Corp.,
a wholly owned subsidiary of Maxim Integrated Products, Inc.
Digital identification and information by momentary contact.
Unique factory-lasered 64-bit registration number assures error free device selection and absolute traceability
because no two parts are alike.
Built-in multidrop controller for 1-Wire net.
Chip-based data carrier compactly stores information.
Data can be accessed while affixed to object.
Button shape is self-aligning with cup-shaped probes.
Durable stainless-steel case engraved with registration number withstands harsh environments.
Easily affixed with self-stick adhesive backing, latched by its flange, or locked with a ring pressed onto its rim.
Presence detector acknowledges when reader first applies voltage.
Meets UL#913 (4th Edit.); Intrinsically Safe Apparatus: approved under Entity Concept for use in Class I,
Division 1, Group A, B, C, and D Locations.
iButton capsule. The DS9107 provides a watertight enclosure that has been rated to IP68 (See
Self-Stick Adhesive Pad
Multipurpose Clip
Mounting Lock Ring
Snap-In Fob
iButton Probe
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DS1922L/DS1922T
®