IN18B20D
INTEGRATED CIRTUIT OF DIGITAL THERMOMETER
OF INDUSTRIAL TEMPERATURE RANGE
(functional equivalent of DS18B20 "Maxim-Dallas Semiconductor")
The IN18B20D is digital thermometer of industrial temperature range
The IC is purposed for temperature measuring and can be used for industrial and analytic measuring in wide range of technological equipment in distributed systems of temperature monitoring and control.
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Fig. 1 – General view of IC in SO case
Main features
Converts temperature to 12-bit digital code;
User-programmable thermometer resolution from 9 to 12 bits;
Alarm signal on temperature is outside of programmed limits
Each IC has a unique 64-bit serial code not available to change by user;
Memory data read/write, data transmitting via 1-wire interface;
Battery and data line power supply available;
Supply voltage UDD range from 3,0 to 5,5 V;
Operating temperature range from minus 55 to plus 125 °С;
ESD protection up to 2000V;
Latch current, min – 100 mA at TA = 25oC.
NC
01
08
NC
NC
02
07
NC
VDD
03
06
NC
DQ
04
05
GND
Fig. 2 – Pinning
Ред.01/15.08.2008
1
IN18B20D
Power supply control
DQ
Interface unit
Control
unit
Internal UDD
ADC
RAM
GND
Upper threshold temperature (alarm) register TH
Cpp
Power
supply
supervisor
VDD
Temperature
sensor
Lower threshold temperature (alarm) register TL
64 bit
EEPROM
UID
(unique
code)
Configuration register
CRC code generator
Fig. 3 – Block diagram
Table 1 – Package pins and contact pad correspondence and description
Pin number
Contact pad
number
Symbol
01
-
NC
Not connected
02
-
NC
Not connected
03
01
VDD
Power supply pin
04
02
DQ
Data I/O
05
03
GND
Common pin
--
04
TST
Test pin
--
05
T
Test pin
--
06
THV
Test pin
06
-
NC
Not connected
07
-
NC
Not connected
08
-
NC
Not connected
2
Description
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Table 2 – Maximum ratings
Symbol
Parameter
Unit
Norm
Min
Max
VDD
Supply voltage
-0,5
6,0
Тa
Ambient temperature
-60
125
V
o
C
Table 3 – Recommended operating modes
Symbol
Parameter
Norm
Min
Max
Unit
Note
V
–
V
1, 2
VDD
Supply voltage
3.0
5.5
VPU
Pullup supply voltage,
capacitive power supply
local power supply
3.0
5.5
3.0
VDD
V
1
at VDD = 5 V
−0.3
V
1, 3
at VDD = 3 V
−0.3
0.8
0.5
V
1, 2, 3
VDD+0.3
VDD+0.3
V
1, 4
capacitive power supply
2.2
3.0
V
1, 2, 4
Operating ambient temperature
-55
125
°С
-
Low level input voltage
VIL
High level input voltage
VIH
Тa
local power supply
Notes:
1 All voltages are referenced to ground..
2 For temperature range from minus 55 to plus 100oC.
3 External driver current 4.0 mA.
4 External driver current 1.0 mA
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Table 4 –Electric parameters
Symbol
Parameter, unit, measurement mode
Consumption current, μA
at 0V ≤ VI ≤ 0.4 V or VDD−0.3 V ≤ VI ≤ VDD
Dynamic Consumption current, μA
at VDD = 5 V
Output current, μA
at VO = 0.4 V
Targets
Min
Max
IDDS
-
IОDD
-
1,0
0,9
1500
1450
IOL
4,0
4,0
Ambient
temperature
25±10
–55; 70
25±10
-55; 125
−
Table 5 –Reference electric parameters
Parameter, unit
Symbol
Input current, μA
- DQ pin
IDQ
Consumption current, μA
IDD
Temperature measurement drift, °С
ΔT
Temperature measurement error, °С
tERR
Measurement
mode
Typical
value
Line driver off,
UDD = 5 V
5
0V ≤ UI ≤ 0,4 V
or
UDD−0,3 V ≤ UI ≤
UDD
After 1000 hours
UDD = 5,5 V
-
0,75
±0,2
±0,5
±2,0
* Typical value is arithmetic mean of parameter value, of measured sampling.
4
Ambient
temperature
25±10
-55; 125
25±10
-55; 70
125
-10; 85
-55; 125
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IN18B20D
Functional description
The IN18B20 uses 1-Wire bus protocol only that implements bus communication using one
control signal. The bus is connected to power supply source via pullup resistor since all devices are linked to the bus via a 3-state or open-drain port. In this bus system, the microprocessor (the control 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.
Each IN18B20D has unique 64-bit code stored in EEPROM UID.
The RAM contains the 2-byte temperature register that stores the temperature value
converted to digital format , two 1-byte upper and lower threshold temperature (alarm) registers (TH and TL), and the 1-byte configuration register. The configuration register allows the
user to set the resolution of the temperature-to-digital conversion to 9, 10, 11, or 12 bits, that
effects on the time of conversion.
The TH, TL and configuration registers are nonvolatile (EEPROM), so they will retain
data when the device is powered down
Another feature of the IN18B20 is the ability to operate without an external power supply. Power is 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 (CPP), which then supplies power to
the device when the bus is low. This method is referred to as “parasite power”. Thus the
maximum measured temperature is + 100 °C. An external power supply is required to expand
the a range of temperatures up to + 125 °C
Temperature conversion mode
The main functionality of the IN18B20 is temperature measuring and A-to-D conversion. The
resolution of the temperature measuring is user-configurable to 9, 10, 11, or 12 bits, corresponding to increments of 0,5000; 0,2500; 0,1250 и 0,0625 °C respectively. The default
resolution is 12-bit. After power-up the IN18B20 stays in idle (non-active) state initially. The
master must issue a Convert T [44h] command to initiate a temperature measurement and Ato-D conversion,. After conversion, the resulting thermal data is stored in the 2-byte temperature register of the RAM and the IN18B20 returns to its non-active state. If the IN18B20 is
powered by an external supply, the master can control the temperature conversion (after instruction [44h]) under the bus state. The IN18B20 will respond by transmitting “0” (on “read
time slots” issued by master) while the temperature conversion is in progress and “1” when
the conversion is done. If the IN18B20 is powered with parasite power, this notification technique is not available since the high level (power supply) must be applied to bus during the
entire temperature conversion. At this case device has to control time of the conversion independently.
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Table 6 – Instruction set
Instruction
Code
Description
Read ROM
[33h]
Read data from EEPROM UID
Match ROM
[55h]
Match data from EEPROM UID (unique
code)
Skip ROM
[CCh]
Skip matching of data from EEPROM UID
(unique code)
Search ROM
[F0h]
Search EEPROM UID (unique code)
Alarm Search
[ECh]
Alarm flag search
Соnvert T1)
[44h]
Initiate a temperature conversion
Read Scratchpad
[BEh]
Read data bytes from RAM and CRC byte
Write Scratchpad
[4Eh]
Write contents of byte 2, 3 and 4 to RAM
Copy Scratchpad
[48h]
Copy RAM content to EEPROM
Recall E2
[B8h]
Copy data from EEPROM to RAM
Read Power Supply
[B4h]
Report on power supply mode
___________
1)
Time to “Strong Pullup” on after “Convert T not exceed 10 μs
Memory
The IN18B20’s memory is organized as shown in Fig. 4. The memory consists of a main
memory (SRAM) and nonvolatile memory (EEPROM). First two registers are registers of
temperature converter storage for the high and low alarm trigger registers (TH and TL) followed by upper and lower threshold temperature (alarm) registers (TH and TL), and configuration register. If the IN18B20 alarm function is not implemented, the TH and TL registers can
be used as general-purpose memory cells.
Byte 0 and byte 1 of the RAM contain the LSB and the MSB of the temperature register, respectively. These bytes are read-only. Bytes 2 and 3 provide access to TH and TL registers.
Byte 4 contains the configuration register data. Bytes 5, 6, and 7 are reserved for internal use
by the device and cannot be overwritten; these bytes will return all “1” when read.
Byte 8 of the RAM is read-only and contains the cyclic redundancy check (CRC) code for
bytes 0 - 7 of the RAM.
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RAM
Byte 0
LSB – low byte of temperature data
(50h)
Byte 1
MSB – high byte of temperature
Data (05h)
EEPROM
Byte 2
TH – high temperature register data
or user «Byte 1»
TH – high temperature register
data or user «Byte 1»
Byte 0
Byte 3
TL – low temperature register data
or user «Byte 2»
TL – low temperature register
data or user «Byte 2»
Byte 1
Byte 4
Configuration register data
Configuration register data
Byte 2
Byte 5
Additional data (FFh)
Byte 6
Additional data (0Ch)
Byte 7
Additional data (10h)
Byte 8
CRC data
Fig. 4 Memory map
Configuration register
Byte 4 of the RAM contains the configuration register. The user can set the conversion resolution of the IN18B20 using bits 5th and 6th bits (R0 and R1) of the configuration register, as
shown in Table 7. The power-up default of these bits is R0 = 1 and R1 = 1 (12-bit resolution).
Note that there is a direct regularity between resolution and conversion time. Bit 7 and bits 0
to 4 in the configuration register are reserved for internal use by the device and cannot be
overwritten; these bits will return “1” when read.
Table 7
R1
R0
Resolution
Max Conversion Time
0
0
9 bit
93,75 ms
(tCONV/8)
0
1
10 bit
187,5 ms
(tCONV/4)
1
0
11 bit
375 ms
(tCONV/2)
1
1
12 bit
750 ms
(tCONV)
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1-Wire bus protocol
The IN18B20 uses a strict 1-Wire communication protocol to insure data integrity. Several
signal types are defined by this protocol: reset pulse, presence pulse, write “0”, write “1”, read
“0”, and read “1”. The master applies all of these signals to bus, with the exception of the
presence pulse. Timing parameters of the 1-Wire bus are shown in Table 8.
Initialization
All communication via 1-Wire bus begins with an initialization sequence. The initialization
sequence consists of a reset pulse from the master followed by a presence pulse from the
slave devices. The presence pulse indicates to the master that one or few slave devices are
on the bus and ready to operate.
The initialization timing diagrams is shown in Fig. 5
READ/WRITE time slots
The bus master writes data to the IN18B20 during write time slots and reads data from
the IN18B20 during read time slots. Time slot is the time interval of the 1-Wire communication protocol.
One bit of data is transmitted per time slot.
Read/write timing diagrams are shown in fig. 6-8
Table 8 – Timing parameters
Parameter, unit
Symbol
Targets
Note
Min
Max
tSLOT
60
93,75
187,5
375
750
120
Write «1» low level duration, μs
tLOW1
1
15
Write «0» low level duration , μs
tLOW0
60
120
Read data valid, μs
tRDV
-
15
Recovery time,μs
tREC
1
-
Reset high level duration, μs
tRSTH
480
-
1
480
-
2
15
60
Temperature conversion time, ms
9-bit resolution
10-bit resolution
11-bit resolution
12-bit resolution
Time interval of the 1-Wire communication protocol, μs
tCONV
1)
Reset low level duration, μs
tRSTL
Presence pulse high level duration, μs
tPDHIGH
60
240
tPDLOW
Presence pulse low level duration, μs
Notes
1. Additional reset or communication sequence cannot start during reset high level.
2.Under with parasite power supply, if tRSTL > 960 μs, a power on reset may occur.
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Driver ТХ «Reset pulse»
Driver RХ «Presense pulse»
tRSTH
UPU
UPU MIN
UIH MIN
UIL MAX
0V
tPDH
tRSTL
Resistor
Driver
IN18B20D
tPDL
480 μs≤ tRSTL < ∞
480 μs ≤ tRSTН < ∞ (includes recovery time)
15 μs ≤ tPDH < 60 μs
60 μs ≤ tPDL < 240 μs
ТX – transmites RX - receives
tRSTL duration has to be less than 960 μs always in order not to mask interruptions issued by
another devices on bus .
Fig. 5 – Initialization timing diagram
tSLOT
UPU
UPU MIN
UIH MIN
tREC
IN18B20D
sampling window
UIL MAX
0V
15 мкс
60 мкс
tLOW0
Resistor
Driver
60 μs ≤ tLOWO < tSLOT < 120 μs
1 μs ≤ tREC < ∞
Fig. 6 – Write “0” timing diagram
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tSLOT
tREC
UPU
UPU MIN
UIH MIN
IN18B20D
sampling window
UIL MAX
0V
tLOW1
15 мкс
60 мкс
Resistor
Driver
60 μs ≤ tSLOT < 120 μs
1 μs ≤ tLOW1 < 15 μs
1 μs ≤ tREC < ∞
Fig. 7 – Write “1” timing diagram
tSLOT
UPU
UPU MIN
UIH MIN
tREC
Driver sampling
window
UIL MAX
0V
tRDV
Resistor
Driver
IN18B20D
60 μs ≤ tSLOT < 120 μs
1 μs ≤ tREC < ∞
tRDV = 15 μs
Fig. 8 – Data read timing diagram
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SO- package (MS-012AA) outline drawing
D
8
5
E1 H
1
4
hx45
c
A1
C
Mounting
plane
e
b
0,25 (0,010) M
L
α
C
Note – Dimensions D, E1 not include the value of fin, which should not exceed 0,25
(0.010) per side.
Table 9
D
E1
H
b
min
4.80
3.80
5.80
0.33
max
5.00
4.00
6.20
0.51
α
A
A1
c
L
h
0°
1.35
0.10
0.19
0.41
0.25
8°
1.75
0.25
0.25
1.27
0.50
e
mm
1.27
inches
min
0.1890 0.1497 0.2284 0.013
max
0.1968 0.1574 0.2440 0.020
0.100
0°
0.0532 0.0040 0.0075 0.016 0.0099
8°
0.0688 0.0090 0.0098 0.050 0.0196
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Contact pad layout
Table 10 Contact pad coordinates
Contact pad number
01
02
03
Coordinates (left bottom corner), mm
X
Y
0,142
0,615
0,742
0,165
1,858
0,166
Contact pad size
0,090х0,090
0,090х0,090
0,090х0,090
04
1,858
1,803
0,090х0,090
05
1,858
2,183
0,090х0,090
06
0,142
1,554
0,090х0,090
07
0,142
1,415
0,090х0,070
08
0,142
1,300
0,090х0,070
09
0,142
1,185
0,090х0,070
10
0,142
1,070
0,090х0,070
Note contact pad size and coordinates are indicated under Passivation layer
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