stcn75 STMicroelectronics, stcn75 Datasheet
stcn75
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stcn75 Summary of contents
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... Shutdown mode to minimize power consumption ■ Output pin (open drain) can be configured for interrupt or comparator/thermostat mode (Dual Purpose Event Pin) ■ Packages: – SO8 (a) – MSOP8 (TSSOP8) a. Contact local ST sales office for availability June 2007 SO8 (M) MSOP8 (TSSOP8) (DS) Rev 5 STCN75 1/35 www.st.com 1 ...
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Contents 1 Summary description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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Data valid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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... Configuration register format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Table 7. Temperature register format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Table 8. T and T register format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 OS HYS Table 9. STCN75 serial bus slave addresses Table 10. Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Table 11. Operating and AC measurement conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Table 12. DC and AC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Table 13. AC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Table 14. SO8 – 8-pin, plastic small outline, package mechanical data Table 15. MSOP8 (TSSOP8) – ...
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List of figures Figure 1. Logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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... Three pins (A0, A1, and A2) are available for address selection, and enable the user to connect devices on the same bus without address conflict. In addition, the serial interface gives the user easy access to all STCN75 registers to customize operation of the device. 6/35 ...
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... Temperature sensor output The STCN75 Temperature Sensor has a dedicated open drain Over-Limit Signal/Interrupt (OS/INT) output which features a thermal alarm function. This function provides a user- programmable trip and turn-off temperature. It can operate in either of two selectable modes: ● Section 2.3: Comparator mode ● Section 2.4: Interrupt At power-up the STCN75 immediately begins measuring the temperature and converting the temperature to a digital value ...
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Figure 2. Connections (SO8 and TSSOP8) 1. SDA and OS/INT are open drain. Figure 3. Functional block diagram Temperature Sensor and Analog-to-Digital Converter (ADC) S 1.3 Pin descriptions See Figure 1 on ...
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GND Ground the reference for the power supply. It must be connected to system ground. 1.3.5 A2, A1, A0 A2, A1, and A0 are selectable address pins for the 3 LSBs of the I They can be ...
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... STCN75 is used in a noisy environment (see The active state of the OS/INT output can be changed via the Polarity Bit (POL) in the Configuration register. The power-up default is active-low. If the user does not wish to use the thermostat capabilities of the STCN75, the OS/INToutput should be left floating. Note: If the thermostat is not used, the T system data ...
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... Thermal alarm function The STCN75 thermal alarm function provides user-programmable thermostat capability and allows the STCN75 to function as a standalone thermostat without using the serial interface. The OS/INT output is the alarm output. This signal is an open drain output, and at power-up, this pin is configured with active-low polarity by default. ...
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Comparator mode In Comparator mode, each time a temperature-to-digital (T-to-D) conversion occurs, the new digital temperature is compared to the value stored in the T tolerance number of consecutive temperature measurements are greater than the value stored in the ...
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... STCN75 will go into a low-power standby state. The OS/INT output will be cleared if the thermostat is operating in Interrupt mode and the OS/INT will remain unchanged in Comparator mode. The 2-wire interface remains operational in Shutdown mode, and writing a '0' to the SD Bit returns the STCN75 to normal operation. STCN75 (consecutive faults) 1 ...
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Temperature data format Table 3 shows the relationship between the output digital data and the external temperature. Temperature data for the Temperature, T represented as a 9-bit, two’s complement word. The left-most bit in the output data stream contains ...
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... Functional description The STCN75 registers have unique pointer designations which are defined in page 16. Whenever any READ/WRITE operation to the STCN75 register is desired, the user must “point” to the device register to be accessed. All of these user-accessible registers can be accessed via the digital serial interface at anytime (seeSection 3 ...
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... READ/WRITE access to all of the bits in the Configuration register except the MSB (Bit7), which is reserved as a “Read only” bit (see thus powers-up in its default state only. Table 6. Configuration register format MSB Byte Bit7 STCN75 0 Default 0 Keys shutdown control bit M = thermostat mode POL = output polarity FT0 = Fault tolerance0 bit 1. Indicates Operation mode ...
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... Temperature register if a read cycle is not ongoing. The STCN75 is continuously evaluating fault conditions regardless of READ or WRITE activity on the bus READ is ongoing, the previous temperature will be read. The readable temperature will be updated upon the completion of the next T-to-D conversion that is not masked by a read cycle ...
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... TMSB = temperature MSB TLSB = temperature LSB TD = temperature Data 1. These are comparable formats to the DS75 and LM75. 3.2 Power-up default conditions The STCN75 always powers up in the following default states: ● Thermostat mode = comparator mode ● Polarity = active-low ● Fault tolerance = 1 fault (i.e., relevant bits set to '0' in the configuration register) ● ...
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... WRITE operations. This device is called the “master” device. The master device also generates the SCL signal which provides the clock signal for all other devices on the bus. These other devices on the bus are called “slave” devices. The STCN75 is a slave device (see Table 9) ...
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Data valid The state of the data line represents valid data when after a start condition, the data line is stable for the duration of the high period of the clock signal. The data on the line may be ...
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... DATA OUTPUT BY RECEIVER 3.5 READ mode In this mode the master reads the STCN75 slave after setting the slave address (see Figure 7). Following the WRITE mode Control Bit (R/W=0) and the Acknowledge Bit, the word address 'An' is written to the on-chip address pointer. There are two READ modes: ● ...
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... Most Significant Data Byte ACK ACK by by STCN75 Master R Data Byte ACK by STCN75 , HYS Stop Least Significant Data Byte Cond. No ACK by by Master Master AI12227 ...
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... WRITE mode In this mode the master transmitter transmits to the STCN75 slave receiver. Bus protocol is shown in Figure 11. Following the START condition and slave address, a logic '0' (R placed on the bus and indicates to the addressed device that word address will follow and written to the on-chip address pointer. ...
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... 24/35 WRITE HYS R Address Byte Pointer Byte ACK by STCN75 Most Significant Data Byte Least Significant Data Byte ACK by STCN75 ACK by STCN75 9 Stop Cond. ACK by by Master STCN75 AI12232 ...
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Typical operating characteristics Figure 14. Temperature variation vs. voltage 140 120 100 –20 –40 – Voltage (V) –20 0.5 85 110 125 5 6 AI12258 25/35 ...
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... These are stress ratings only and operation of the device at these or any other conditions above those indicated in the Operating sections of this specification is not implied. Exposure to Absolute maximum rating conditions for extended periods may affect device reliability. Refer also to the STMicroelectronics SURE Program and other relevant quality documents. Table 10. ...
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DC and AC parameters This section summarizes the operating measurement conditions, and the DC and AC characteristics of the device. The parameters in the DC and AC characteristics Tables that follow, are derived from tests performed under the Measurement ...
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Table 12. DC and AC characteristics Sym Description V Supply voltage DD V supply current, DD active temperature conversions supply current, DD communication only Shutdown mode supply I current, serial port DD1 inactive Accuracy for corresponding range ...
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Figure 15. Bus timing requirements sequence SDA tBUF tHD:STA tR SCL P S Table 13. AC characteristics Sym f SCL clock frequency SCL t Time the bus must be free before a new transmission can start BUF t SDA and ...
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Package mechanical data In order to meet environmental requirements, ST offers these devices in ECOPACK packages. These packages have a lead-free second level interconnect. The category of second Level Interconnect is marked on the package and on the inner ...
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Figure 16. SO8 – 8-pin, plastic small package outline Drawing is not to scale. Table 14. SO8 – 8-pin, plastic small outline, package mechanical data millimetres Symbol Typ Min A A1 0.10 ...
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Figure 17. MSOP8 (TSSOP8) – 8-lead, thin shrink small package (3x3) outline A ccc 1. Drawing is not to scale. Table 15. MSOP8 (TSSOP8) – 8-lead, thin shrink small package (3x3) mech. data Sym Typ 0.85 b ...
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... DS = MSOP8 (TSSOP8) Temperature range 2 = –55 to 125°C Shipping method F = ECOPACK package, Tape & Reel E = ECOPACK package, Tube 1. Contact local ST sales office for availability For other options, or for more information on any aspect of this device, please contact the ST sales office nearest you. (1) STCN75 33/35 ...
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Revision history Table 17. Revision history Date Revision 25-Jul-2006 17-Nov-2006 22-Jan-2007 02-Mar-2007 06-Jun-2007 34/35 1 Initial release Changed document to new template; document status updated from target specification to preliminary data; updated footnotes in Table 1: Signal 2 V ...
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... Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST’s terms and conditions of sale. ...