Datenblatt-Suchmaschine für elektronische Bauteile |
|
TC773.3MCTTR Datenblatt(PDF) 9 Page - Microchip Technology |
|
TC773.3MCTTR Datenblatt(HTML) 9 Page - Microchip Technology |
9 / 22 page 2002 Microchip Technology Inc. DS20092A-page 9 TC77 3.1 Temperature Data Format A 13-bit two’s complement digital word is used to rep- resent the temperature. The Least Significant Bit (LSb) is equal to 0.0625°C. Note that the last two LSb bits (Bit 0 and 1) are tri-stated and are represented as a logic ‘1’ in the table. Bit 2 is set to logic ‘1’ after the completion of the first temperature conversion following a power- up or voltage reset event. TABLE 3-1: TC77 OUTPUT An over-temperature condition can be determined by reading only the first few Most Significant Bits (MSb) of the temperature data. For example, the microproces- sor could read only the first four bits of the Temperature register in order to determine that an over-temperature condition exists. 3.2 Power-Up And Power-Down The TC77 is in the Continuous Temperature Conver- sion mode at power-up. The first valid temperature con- version will be available approximately 300 ms (refer to “Temperature to Bits Converter” section listed in the DC characteristics table) after power-up. Bit 2 of the Tem- perature register is set to a logic ‘1’ after the completion of the first temperature conversion following a power- up or voltage reset event. Bit 2 is set to logic ‘0’ during the time needed to complete the first temperature con- version. Thus, the status of bit 2 can be monitored to indicate the completion of the first temperature conver- sion. A supply voltage lower than 1.6V (typ.) is considered a power-down state for the TC77. The device will reset itself and continue its normal Continuous Conversion mode of operation when the supply voltage rises above the nominal 1.6V. A minimal supply voltage of 2.7V is required in order to ensure proper operation of the device. 3.3 Serial Bus Interface The serial interface consists of the Chip Select (CS), Serial Clock (SCK) and Serial Data (SI/O) signals. The TC77 meets the SPI and MICROWIRE bus specifica- tions, with the serial interface designed to be compati- ble with the Microchip PICmicro® family of microcontrollers. The CS input is used to select the TC77 when multiple devices are connected to the serial clock and data lines. The CS line is also used to synchronize the data, which is written to, or read from, the device when CS is equal to a logic ‘0’ voltage. The SCK input is disabled when CS is a logic ‘1’. The falling edge of the CS line initiates communication, while the rising edge of CS completes the communication. The SCK input is provided by the external microcontrol- ler and is used to synchronize the data on the SI/O line. The Temperature and Manufacturer ID registers are read only while the Configuration register is a read/ write register. Figure 3-2 provides a timing diagram of a read opera- tion of the Temperature register. Communication with the TC77 is initiated when the CS goes to a logic ‘0’. The Serial I/O signal (SI/O) then transmits the first bit of data. The microcontroller serial I/O bus master clocks the data in on the rising edge of SCK. The falling edge of SCK is then used to clock out the rest of the data. After 14 bits of data (thirteen temperature bits and Bit 2) have been transmitted, the SI/O line is then tri-stated. Note that CS can be taken to a logic ‘1’ at any time dur- ing the data transmission if only a portion of the temper- ature data information is required. The TC77 will complete the conversion, and the output shift register will be updated, if CS goes to the inactive state while in the middle of a conversion. Figure 3-3 provides a timing diagram of a multi-byte communication operation consisting of a read of the Temperature Data register, followed by a write to the Configuration register. The first 16 SCK pulses are used to transmit the TC77's temperature data to the microcontroller. The second group of 16 SCK pulses are used to receive the microcontroller command to place the TC77 either in Shutdown or Continuous Tem- perature Conversion mode. Note that the TC77 is in the Continuous Temperature Conversion mode at power- up. The data written to the TC77’s Configuration register should be either all 0’s or all 1’s, corresponding to either the Continuous Temperature Conversion or Shutdown mode, respectively. The TC77 is in Shut- down mode when Bits C0 to C7 are all equal to 1’s. The TC77 will be in the Continuous Conversion mode if a ‘0’ in any bit location from C0 to C7 is written to the Configuration register. Temperature Binary MSB / LSB Hex +125°C 0011 1110 1000 0111 3E 87h +25°C 0000 1100 1000 0111 0B 87h +0.0625°C 0000 0000 0000 1111 00 0Fh 0°C 0000 0000 0000 0111 00 07h -0.0625°C 1111 1111 1111 1111 FF FFh -25°C 1111 0011 1000 0111 F3 87h -55°C 1110 0100 1000 0111 E4 87h |
Ähnliche Teilenummer - TC773.3MCTTR |
|
Ähnliche Beschreibung - TC773.3MCTTR |
|
|
Link URL |
Privatsphäre und Datenschutz |
ALLDATASHEETDE.COM |
War ALLDATASHEET hilfreich? [ DONATE ] |
Über Alldatasheet | Werbung | Kontakt | Privatsphäre und Datenschutz | Linktausch | Hersteller All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |