Datasheet MAX30208 (Maxim) - 8
| Hersteller | Maxim |
| Beschreibung | ±0.1°C Accurate, I2C Digital Temperature Sensor |
| Seiten / Seite | 29 / 8 — Measuring Temperature. Table 1. FIFO Data Format. TEMPERATURE (°C). … |
| Dateiformat / Größe | PDF / 741 Kb |
| Dokumentensprache | Englisch |
Measuring Temperature. Table 1. FIFO Data Format. TEMPERATURE (°C). DIGITAL OUTPUT (BINA-. DIGITAL OUTPUT (HEXADECI-
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Measuring Temperature
FIFO Data register (see Figure 1). The data is two’s com- The device powers up in a low-power standby state. To plement where the MSB determines the sign of the tem- initiate a temperature measurement the master must write perature with an MSB of 1 indicating a negative tempera- a ‘1’ to the CONVERT_T bit in the TEMP_SENSOR_ ture and an MSB of 0 indicating a positive temperature. SETUP[0x14] register. Do not sample at more than 20Hz, To calculate the temperature from the measurement as the total time for a sample to be ready after sending a result, convert the two’s complement value to the decimal conversion command can be up to 50ms. Following the value and use the following equation for all bit resolutions. conversion, which takes 15ms(typ), the resulting tempera- T = Decimal Value × 0.005 ture data is store in the FIFO and the device returns to the standby state. CONVERT_T automatically clears to ‘0.’ For example, if the result is 0x1CE8, convert to decimal to get 7400, then T = 7400 × 0.005 or 37°C. Table 1 gives The output temperature data is calibrated in degrees examples of digital output data and the corresponding Celsius. The temperature data is stored as a left-justified, temperature reading. 16-bit sign-extended two’s complement number in the FIFO DATA REGISTER FORMAT Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8 MSB T15 T14 T13 T12 T11 T10 T9 T8 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 LSB T7 T6 T5 T4 T3 T2 T1 T0 Figure 1. Temperature Data Register Format
Table 1. FIFO Data Format TEMPERATURE (°C) DIGITAL OUTPUT (BINA- DIGITAL OUTPUT (HEXADECI- DIGITAL OUTPUT (DECI- RY) MAL) MAL)
+70 0011 0110 1011 0000 36B0 14,000 +50 0010 0111 0001 0000 2710 10,000 +41 0010 0000 0000 1000 2008 8,200 +37 0001 1100 1110 1000 1CE8 7,400 +35.8 0001 1011 1111 1000 1BF8 7,160 +25 0001 0011 1000 1000 1388 5,000 +15 0000 1011 1011 1000 0BB8 3,000 +0.04 0000 0000 0000 1000 0008 8 +0.02 0000 0000 0000 0100 0004 4 +0.01 0000 0000 0000 0010 0002 2 +0.005 0000 0000 0000 0001 0001 1 0 0000 0000 0000 0000 0000 0 www.maximintegrated.com Maxim Integrated │ 8
Measuring Temperature
FIFO Data register (see Figure 1). The data is two’s com- The device powers up in a low-power standby state. To plement where the MSB determines the sign of the tem- initiate a temperature measurement the master must write perature with an MSB of 1 indicating a negative tempera- a ‘1’ to the CONVERT_T bit in the TEMP_SENSOR_ ture and an MSB of 0 indicating a positive temperature. SETUP[0x14] register. Do not sample at more than 20Hz, To calculate the temperature from the measurement as the total time for a sample to be ready after sending a result, convert the two’s complement value to the decimal conversion command can be up to 50ms. Following the value and use the following equation for all bit resolutions. conversion, which takes 15ms(typ), the resulting tempera- T = Decimal Value × 0.005 ture data is store in the FIFO and the device returns to the standby state. CONVERT_T automatically clears to ‘0.’ For example, if the result is 0x1CE8, convert to decimal to get 7400, then T = 7400 × 0.005 or 37°C. Table 1 gives The output temperature data is calibrated in degrees examples of digital output data and the corresponding Celsius. The temperature data is stored as a left-justified, temperature reading. 16-bit sign-extended two’s complement number in the FIFO DATA REGISTER FORMAT Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8 MSB T15 T14 T13 T12 T11 T10 T9 T8 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 LSB T7 T6 T5 T4 T3 T2 T1 T0 Figure 1. Temperature Data Register Format
Table 1. FIFO Data Format TEMPERATURE (°C) DIGITAL OUTPUT (BINA- DIGITAL OUTPUT (HEXADECI- DIGITAL OUTPUT (DECI- RY) MAL) MAL)
+70 0011 0110 1011 0000 36B0 14,000 +50 0010 0111 0001 0000 2710 10,000 +41 0010 0000 0000 1000 2008 8,200 +37 0001 1100 1110 1000 1CE8 7,400 +35.8 0001 1011 1111 1000 1BF8 7,160 +25 0001 0011 1000 1000 1388 5,000 +15 0000 1011 1011 1000 0BB8 3,000 +0.04 0000 0000 0000 1000 0008 8 +0.02 0000 0000 0000 0100 0004 4 +0.01 0000 0000 0000 0010 0002 2 +0.005 0000 0000 0000 0001 0001 1 0 0000 0000 0000 0000 0000 0 www.maximintegrated.com Maxim Integrated │ 8