LM77-3EVAL National Semiconductor, LM77-3EVAL Datasheet
LM77-3EVAL
Specifications of LM77-3EVAL
Related parts for LM77-3EVAL
LM77-3EVAL Summary of contents
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... Separate open-drain outputs for Interrupt and Critical Temperature shutdown ■ Shutdown mode to minimize power consumption ■ LM77s can be connected to a single bus ■ 9-bit + sign output; full-scale reading of over 128°C ■ SOP and MSOP 8-lead packages Key Specifications ■ ...
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... Order Number LM77CIM-3; LM77CIM-3/NOPB LM77CIMX-3; LM77CIMX-3/NOPB LM77CIM-5; LM77CIM-5/NOPB LM77CIMX-5; LM77CIMX-5/NOPB LM77CIMM-3; LM77CIMM-3/NOPB LM77CIMMX-3; LM77CIMMX-3/NOPB LM77CIMM-5; LM77CIMM-5/NOPB LM77CIMMX-5 www.national.com SOP8 or MSOP 10013602 LM77 See NS Package Number M08A or MM08A Supply Voltage Package 3.3V SOP8, M08A 3.3V SOP8, M08A 5V SOP8, M08A 5V SOP8, M08A 3.3V MSOP8, MUA08A 1000 Units on Tape and Reel 3 ...
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Pin Descriptions Label Pin # SDA 1 Serial Bi-Directional Data Line. Open Drain Output SCL 2 Serial Bus Clock Input T_CRIT_A 3 Critical Temperature Alarm Open Drain Output GND 4 Power Supply Ground INT 5 Interrupt Open Drain Output +V ...
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... −25°C to +100° −55°C to +125°C A (Note 10) (Note 11 Inactive Active Shutdown Mode (Note 13, Note 14) (Note 14) (Note 14) (Note 14) =+5 Vdc ±10% for LM77CIM-5, LM77CIMM-5 and + MIN Conditions (Note 4) (Note 3) (Note 1, Note 5) T −55°C to +125°C )(Note 7) +3 ...
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... Note 10: 9 bits + sign, two's complement Note 11: This specification is provided only to indicate how often temperature data is updated. The LM77 can be read at any time without regard to conversion state (and will yield last conversion result conversion is in process it will be interrupted and restarted after the end of the read. ...
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... The T_CRIT_A hardwire output mirrors the T_CRIT_A flag unless the part is read. When the flag is true, the T_CRIT_A output is asserted regardless of Interrupt Mode. Reading the LM77 resets the T_CRIT_A output until the internal conver- sion is completed typical system, T_CRIT_A is used to immediately shutdown or reset the system. Thus, once T_CRIT_A asserts the system normally would not be reading the LM77 via the I2C bus ...
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... SERIAL BUS INTERFACE The LM77 operates as a slave on the Serial Bus, so the SCL line is an input (no clock is generated by the LM77) and the SDA line is a bi-directional serial data line. According to Serial Bus specifications, the LM77 has a 7-bit slave address. The five most significant bits of the slave address are hard wired inside the LM77 and are “ ...
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... Note: Event Interrupt mode is drawn as if the user is reading the part. If the user doesn't read, the outputs would go low and stay that way until the LM77 is read. 1.4 TEMPERATURE DATA FORMAT Temperature data can be read from the Temperature and Set Point registers; and written to the Set Point registers. Tem- ...
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... Master (No Acknowledge is typically used as a signal for the slave that the Master has read its last byte). An inadvertent 8-bit read from a 16-bit register, with the D7 bit low, can cause the LM77 to stop in a state where the SDA line is held low as shown in Figure further bus communication until at least 9 additional clock cy- cles have occurred ...
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FIGURE 4. Inadvertent 8-Bit Read from 16-Bit Register where D7 is Zero (“0”) www.national.com 10 10013608 ...
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... D0: Shutdown - When set to 1 the LM77 goes to low power shutdown mode. Power up default of “0”. D1: Interrupt mode - 0 is Comparator Interrupt mode Event Interrupt mode. Power up default of “0”. D2, D3: T_CRIT_A and INT Polarity - 0 is active low ac- tive high. Outputs are open-drain. Power up default of “0” ...
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Timing Diagrams Typical 2-Byte Read From Preset Pointer Location Such as Temp or Comparison Registers Typical Pointer Set Followed by Immediate Read for 2-Byte Register such as Temp or Comparison Registers Typical 1-Byte Read from Configuration ...
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... Mode, the LM77 simply stops issuing interrupts. The 2nd event is another identical rise in temperature. The 3rd event is typical of a drop in temperature. This is one of the conditions that demonstrates the power of the LM77, as the user receives notification that a lower limit is exceeded in such a way that temperature is dropping. ...
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... Note: Event Interrupt mode is drawn as if the user is reading the part. If the user doesn't read, the outputs would go low and stay that way until the LM77 is read. FIGURE 7. Temperature Response Diagram for ACPI Implementation 4.0 Typical Applications www.national.com FIGURE 8. Typical Application ...
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... FIGURE 9. Remote HVAC temperature sensor communicates via 3 wires, including thermostat signals. FIGURE 10. ACPI Compatible Terminal Alarm Shutdown. By powering the LM77 from auxilary output of the power supply, a non-functioning overheated computer can be powered down to preserve as much of the system as possible. 15 10013617 10013619 www.national.com ...
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... Wide) Molded Small Outline Package (SOP), Order Number LM77CIM-3, LM77CIMX-3, LM77CIM-5 or LM77CIMX-5 8-Lead (0.150 Wide) Molded Mini Small Outline Package (MSOP), Order Number LM77CIMM-3, LM77CIMMX-3, LM77CIMM-5 or LM77CIMMX-5 www.national.com inches (millimeters) unless otherwise noted JEDEC Registration Number MS-012 (variation AA), ...
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