NoticeDS18B20 1 - Wire Digital Thermometer Module
Contents
Overview
DS18B20 is a single-bus digital temperature sensor with features of ultra-small size, wide range of applicable voltage and measurable temperature and high resolution, etc. , which can be applied to temperature control, industrial systems, consumer products, thermometers or any thermal measurement system.
Features
1. Plug and play, easy to use. Compatible with the mainstream 2.54 interfaces and 4-Pin Grove interfaces in the market.
2. With use of M4 standard fixed holes, compatible with M4-standard kits such as Lego and Makeblock.
3. Rotatable detecting direction for better adaption.
Specifications
| PCB size | 33.2mm X 14.0mm X 1.6mm |
| Working voltage | 3.3 or 5V DC |
| Operating voltage | 3.3 or 5V DC |
| Measurable range | -55~+125℃ |
| Measurement resolution | 9~12bits（programmable） |
| Compatible interfaces | 2.54 3-pin interface and 4-pin Grove interface(1) |
Note 1: S for digital input/output port, V and G for voltage at the common collector and ground respectively
DC electrical characteristics
| Parameter | Min. | Typical | Max. | Unit |
| Working voltage | 3 | 5 | 5.5 | VDC |
| Working current（VCC=5V，T=25℃） | - | 1 | 1.5 | mA |
| Sampling interval | 1 | - | - | s |
| Accuracy (-10~+85℃) | - | - | ±0.5 | ℃ |
| Accuracy (-55~+125℃) | - | - | ±2 | ℃ |
| Logic input low level VIL | -0.3 | - | 0.8 | V |
| Logic input high level VIH | 2.2 | - | 5.5/VCC+0.3 | V |
AC electrical characteristics
| Parameter | Min. | Typical | Max. | Unit |
| Temperature conversion time tCONV (9-bit accuracy) | - | - | 93.75 | ms |
| Temperature conversion time tCONV (10-bit accuracy) | - | - | 187.5 | ms |
| Temperature conversion time tCONV (11-bit accuracy) | - | - | 375 | ms |
| Temperature conversion time tCONV (12-bit accuracy) | - | - | 750 | ms |
| Time for strong pullup on tSPON | - | - | 10 | us |
| Time slot tSLOT | 60 | - | 120 | us |
| Recovery time tREC | 1 | - | - | us |
| Write 0 low time tLOW0 | 60 | - | 120 | us |
| Write 1 low time tLOW1 | 1 | - | 15 | us |
| Read data valid tRDV | - | - | 15 | us |
| Reset time high tRSTH | 480 | - | - | us |
| Reset time low tRSTL | 480 | - | - | us |
| Presence-detect high tPDHIGH | 15 | - | 60 | us |
| Presence-detect low tPDLOW | 60 | - | 240 | us |
| Capacitance CIN/OUT | - | - | 25 | pF |
Instruction
Each DS18B20 has a unique 64-bit serial code, which allows multiple DS18B20s to function on the same 1-Wire bus. The figure below shows a block diagram of DS18B20. The scratchpad memory contains the 2-byte temperature register that stores the datal output from the temperature sensor. In addition, the scratchpad provides access to direct temperature alarm trigger 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. The TH, TL, and configuration registers are nonvolatile (EEPROM), so they will retain data when the device is powered down.
