LM81BIMT-3/NOPB National Semiconductor, LM81BIMT-3/NOPB Datasheet
LM81BIMT-3/NOPB
Specifications of LM81BIMT-3/NOPB
*LM81BIMT-3/NOPB
LM81BIMT-3
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LM81BIMT-3/NOPB Summary of contents
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... DAC output for controlling fan speed n 2 fan speed monitoring inputs Typical Application # Indicates Active Low (“Not”) © 2002 National Semiconductor Corporation n Chassis Intrusion detector input n WATCHDOG comparison of all monitored values n SMBus 1.0 (LM81C) and 1.1 (LM81B) Serial Bus ...
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... Ordering Information Temperature Range −40˚C T +125˚C A Order Number Device Marking 1 LM81BIMT-3 LM81BIMT-3 2 LM81BIMTX-3 LM81BIMT-3 1 LM81CIMT-3 LM81CIMT-3 2 LM81CIMTX-3 LM81CIMT-3 1 Note: -Rail transport media, 62 parts per rail 2 -Tape and reel transport media, 3400 parts per reel Connection Diagram www.national.com NS Package SMBus ...
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Block Diagram Pin Description Pin Pin Number Name(s) Number of Pins A0/NTEST_OUT SMBData 3 SMBCLK 4 FAN1-FAN2 5 T_CRIT_A (+2. +3.8V) Type 1 Digital I/0 The lowest order programmable bit ...
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Pin Description (Continued) Pin Pin Number Name(s) Number of Pins INT 10 DACOut/NTEST_IN 11 RESET 12 GND 13 Vccp2 14 +12Vin 15 +5Vin 16 +3.3Vin 17 +2.5Vin 18 Vccp1 19 VID4-VID0 20-24 TOTAL PINS www.national.com Type 1 Digital Output Interrupt ...
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... Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. + Positive Supply Voltage (V ) Voltage on Any Input or Output Pin: +12Vin, T_CRIT_A A0, A1, DACOut +2.5Vin, +3.3Vin All other pins Input Current at any Pin (Note 4) ...
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DC Electrical Characteristics The following specifications apply for +2.8V for all other limits MIN MAX Symbol Parameter DAC CHARACTERISTICS Resolution DAC Error DAC Error Temperature Sensitivity DAC Error Power ...
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DC Electrical Characteristics The following specifications apply for +2.8V for all other limits MIN MAX Symbol Parameter DIGITAL OUTPUTS (NTEST_OUT) V Logical “1” Output Voltage OUT(1) V Logical “0” ...
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AC Electrical Characteristics The following specifications apply for +2.8V face limits apply for MIN Symbol SERIAL BUS TIMING CHARACTERISTICS t SMBCLK (Clock) Period 1 t SMBCLK and SMBData Rise Time rise t SMBCLK ...
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... Note 6: The human body model is a 100 pF capacitor discharged through a 1.5 k directly into each pin. Note 7: See the section titled “Surface Mount” found in any post 1986 National Semiconductor Linear Data Book for other methods of soldering surface mount devices. Note 8: Parasitics and or ESD protection circuitry are shown in the figure below for the LM81’s pins. The nominal breakdown voltage of the zener D3 is 6.5V. Care should be taken not to forward bias the parasitic diode, D1, present on pins: A0/NTEST_OUT, A1 and DACOut/NTEST_IN ...
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Test Circuit Functional Description 1.0 GENERAL DESCRIPTION The LM81 provides 6 analog inputs, a temperature sensor, a Delta-Sigma ADC (Analog-to-Digital Converter), a DAC out- put, 2 fan speed counters, WATCHDOG registers, and a variety of inputs and outputs on a ...
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Functional Description Interrupt source. In addition, the Configuration Register has a control bit to enable or disable the hardware Interrupt. Another hardware Interrupt line available T_CRIT_A (Critical Temperature Alarm Output) is used to signal a catastrophic overtemperature event. Having a ...
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Functional Description 2.1 Internal Registers of the LM81 TABLE 1. The internal registers and their corresponding internal LM81 addresses are as follows: Register LM81 Internal Hex Configuration Register Interrupt Status Register 1 Interrupt Status Register 2 Interrupt Mask Register 1 ...
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Functional Description 2.2 Serial Bus Interface (a) Serial Bus Write to the Internal Address Register followed by the Data Byte (b) Serial Bus Write to the Internal Address Register Only (c) Serial Bus Read from a Register with the Internal ...
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Functional Description 3.0 USING THE LM81 3.1 Power On When power is first applied, the LM81 performs a “power on reset” on several of its registers. The power on condition of the LM81’s registers in shown in Table 1 Registers ...
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Functional Description 3.5 Reading Conversion Results The conversion results are available in the Value RAM. Conversions can be read at any time and will provide the result of the last conversion. Because the ADC stops, and starts a new conversion ...
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Functional Description equal to its LOW limit will cause a flag to be set in its Interrupt Status Register. This flag will activate the INT out- put when its mask bit is set low. Mask bits are found in the ...
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Functional Description (a) Fan with Tach Pull-Up to +5V (c) Fan with Tach Pull-Up to +12V and Diode Clamp Counts are based on 2 pulses per revolution tachometer outputs. RPM Time per Revolution 4400 13.64 ms 3080 19.48 ms 2640 ...
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Functional Description 7.0 DAC OUTPUT The LM81 provides an 8-bit DAC (Digital-to-Analog Con- verter) with an output range 1.25 volts (4.88 mV LSB). This DAC can be used in any way, but in most applications of the ...
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Functional Description 8.0 TEMPERATURE MEASUREMENT SYSTEM The LM81 temperature sensor and ADC produce 9-bit or 12-bit two’s-complement temperature data. A digital com- parator compares the temperature user-programmable High, Low, Critical setpoints and Hyster- esis values. (Non-Linear Scale for Clarity) FIGURE ...
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Functional Description 8.2 Temperature Interrupts INT and T_CRIT_A outputs are provided for temperature interrupt. Temperature interrupts have a normal and an ex- tended option of operation. Each option has three different modes of operation: Repetitive Interrupt, One-Time Interrupt and Comparator. ...
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Functional Description Extended Repetitive Interrupt Mode is shown in Figure 14 and operates in the following way: Once activated, all inter- rupts remain activated until reset by a read of the Interrupt Status Register 1. Once activated all T_CRIT_A interrupts ...
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Functional Description 9.0 THE LM81 INTERRUPT STRUCTURE Figure 17 depicts the Interrupt Structure of the LM81. The LM81 can generate Interrupts as a result of each of its internal WATCHDOG registers on the analog, temperature, and fan inputs. External Interrupts ...
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Functional Description masks for each Interrupt. As described in Section 3.3, the hardware Interrupt line can also be enabled/disabled in the Configuration Register. T_CRIT_A interrupt is dedicated to temperature and is indi- cated in Extended Mode Register 1. Extended Mode ...
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Functional Description 12.0 FAN MANUFACTURERS Manufacturers of cooling fans with tachometer outputs are listed below: NMB Tech 9730 Independence Ave. Chatsworth, California 91311 818 341-3355 818 341-8207 Model Num- Frame Size ber 2408NL 2.36 in sq. X 0.79 in (60 ...
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Functional Description 13.0 REGISTERS AND RAM 13.1 Address Register The main register is the ADDRESS Register. The bit designations are as follows: Bit Name Read/ Write 7-0 Address Write Pointer Bit 7 Bit 6 Bit 13.2 Address ...
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Functional Description 13.3 Configuration Register — Address 40h < > Power on default – 7:0 = 00001000 binary Bit Name Read/ Write 0 Start Read/Write 1 INT Enable Read/Write 2 Reserved Read/Write 3 INT_Clear Read/Write 4 RESET Read/Write 5 Reserved ...
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Functional Description 13.4 Interrupt Status Register 1 — Address 41h < > Power on default – 7:0 = 0000 0000 binary Bit Name Read/Write 0 +2.5Vin Read Only 1 Vccp1 Read Only 2 +3.3Vin Read Only 3 +5Vin Read Only ...
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Functional Description 13.7 Interrupt Mask Register 2 — Address 44h < > Power on default – 7:0 = 0000 0000 binary Bit Name Read/ Write 0 +12Vin Read/Write 1 Vccp2 Read/Write 2 Reserved Read/Write 3 Reserved Read/Write 4 Chassis Intrusion ...
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Functional Description 13.10 VID/Fan Divisor Register — Address 47h < > Power on default – 7:4 is 0101, and Bit Name Read/Write < > 0-3 VID 3:0 Read Only 4-5 FAN1 RPM Read/Write Control 6-7 FAN2 RPM Read/Write Control 13.11 ...
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Functional Description 13.14 Extended Mode Register 1 — Address 4Ch < > Power on default – 7:0 = 0100 0100 binary Bit Name Read/Write 0 Extended Mode Read/Write Enable 1 LOW Limit Mask Read/Write Bit 2-3 T_CRIT_A Read/Write Interrupt Mode ...
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... Reserved 3Eh Company Identification. The number in this register identifies National Semiconductor (0000 0001) 3Fh Stepping Register LM81 revision number (0000 0011) Note: Setting all ones to the high limits for voltages and fans (0111 1111 binary for temperature) means interrupts will never be generated except the case when voltages go below the low limits ...
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Typical Application FIGURE 19. In this PC application the LM81 monitors temperature, fan speed for 2 fans, and 6 power supply voltages. It also monitors an optical chassis intrusion detector. The LM81 provides a DAC output that can be used ...
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... Physical Dimensions Order Number LM81BIMT-3, LM81BIMTX-3, LM81CIMT-3 or LM81CIMTX-3 LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or ...