DS18S20+ Dallas Semiconductor, DS18S20+ Datasheet - Page 2

• Manufacturer Part Number: DS18S20+
• Description: Thermometer; Digital, -55 to 125 C Range, 9 Bit Resolution, 1-Wire Output, TO-92
• Manufacturer: Dallas Semiconductor

Specifications of DS18S20+

• Body Style: TO-92
• Brand/series: DS18S20
• Function: Thermostat
• Output: Voltage
• Primary Type: Thermostat
• Range, Measurement: 125 °C
• Termination: Solder
• Voltage, Supply: 5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

ORDERING INFORMATION
+Denotes a lead-free package. A “+” will appear on the top mark of lead-free packages.
T&R = Tape and reel.
* TO-92 packages in tape and reel can be ordered with straight or formed leads. Choose “SL” for straight leads. Bulk TO-92 orders are straight
leads only.
PIN DESCRIPTION
OVERVIEW
Figure 1 shows a block diagram of the DS18S20, and pin descriptions are given in the Pin Description
table. The 64-bit ROM stores the device’s unique serial code. The scratchpad memory contains the 2-byte
temperature register that stores the digital output from the temperature sensor. In addition, the scratchpad
provides access to the 1-byte upper and lower alarm trigger registers (T
are nonvolatile (EEPROM), so they will retain data when the device is powered down.
The DS18S20 uses Maxim’s exclusive 1-Wire bus protocol that implements bus communication using
one control signal. The control line requires a weak pullup resistor since all devices are linked to the bus
via a 3-state or open-drain port (the DQ pin in the case of the DS18S20). In this bus system, the
microprocessor (the master device) identifies and addresses devices on the bus using each device’s unique
64-bit code. Because each device has a unique code, the number of devices that can be addressed on one
bus is virtually unlimited. The 1-Wire bus protocol, including detailed explanations of the commands and
“time slots,” is covered in the 1-Wire Bus System section.
Another feature of the DS18S20 is the ability to operate without an external power supply. Power is
instead supplied through the 1-Wire pullup resistor via the DQ pin when the bus is high. The high bus
signal also charges an internal capacitor (C
low. This method of deriving power from the 1-Wire bus is referred to as “parasite power.” As an
alternative, the DS18S20 may also be powered by an external supply on V
DS18S20
DS18S20+
DS18S20/T&R
DS18S20+T&R
DS18S20-SL/T&R
DS18S20-SL+T&R
DS18S20Z
DS18S20Z+
DS18S20Z/T&R
DS18S20Z+T&R
TO-92
—
1
2
3
PART
PIN
1, 2, 6, 7,
SO
5
4
3
8
NAME
GND
N.C.
V
DQ
DD
–55°C to +125°C
–55°C to +125°C
–55°C to +125°C
–55°C to +125°C
–55°C to +125°C
–55°C to +125°C
–55°C to +125°C
–55°C to +125°C
–55°C to +125°C
–55°C to +125°C
TEMP RANGE
Ground
Data Input/Output. Open-drain 1-Wire interface pin. Also provides
power to the device when used in parasite power mode (see the
Powering the DS18S20 section.)
Optional V
power mode.
No Connection
PP
), which then supplies power to the device when the bus is
DD
. V
PIN-PACKAGE
3 TO-92
3 TO-92
3 TO-92 (2000 Piece)
3 TO-92 (2000 Piece)
3 TO-92 (2000 Piece)*
3 TO-92 (2000 Piece)*
8 SO
8 SO
8 SO (2500 Piece)
8 SO (2500 Piece)
DD
must be grounded for operation in parasite
FUNCTION
H
and T
DD
.
L
). The T
TOP MARK
DS18S20
DS18S20
DS18S20
DS18S20
H
DS1820
DS1820
DS1820
DS1820
DS1820
DS1820
and T
L
registers
DS18S20