LM80CIMT-3/NOPB National Semiconductor, LM80CIMT-3/NOPB Datasheet - Page 15

• Manufacturer Part Number: LM80CIMT-3/NOPB
• Description: IC MONITOR SYS HARDWAR 24-TSSOP
• Manufacturer: National Semiconductor
• Series: PowerWise®r

Specifications of LM80CIMT-3/NOPB

• Function: Hardware Monitor
• Topology: ADC, Comparator, Fan Speed Counter, Register Bank
• Sensor Type: External & Internal
• Sensing Temperature: -25°C ~ 125°C, External Sensor
• Output Type: I²C™
• Output Alarm: No
• Output Fan: No
• Voltage - Supply: 2.8 V ~ 5.75 V
• Operating Temperature: -25°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 24-TSSOP
• Number Of Voltages Monitored: 7
• Manual Reset: Not Resettable
• Watchdog: Watchdog
• Battery Backup Switching: No
• Power-up Reset Delay (typ): 500 ns
• Supply Voltage (max): 5.75 V
• Supply Voltage (min): 2.8 V
• Supply Current (typ): 200 uA (Typ)
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 25 C
• Power Fail Detection: No
• Ic Output Type: Digital
• Sensing Accuracy Range: ± 3°C
• Supply Current: 200µA
• Supply Voltage Range: 2.8V To 5.75V
• Resolution (bits): 8bit
• Sensor Case Style: TSSOP
• No. Of Pins: 24
• Accuracy %: 3°C
• Rohs Compliant: Yes
• For Use With: LM80EVAL - EVALUATION BOARD FOR LM80
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: *LM80CIMT-3; *LM80CIMT-3/NOPB; LM80CIMT-3

Divide by 1
Divide by 2
Divide by 4
Divide by 8
Mode Select
Counts are based on 2 pulses per revolution tachometer out-
puts.
7.0 TEMPERATURE MEASUREMENT SYSTEM
The LM80 bandgap type temperature sensor and ADC per-
form 9-bit or a 12-bit two's-complement conversions of the
(Non-Linear Scale for Clarity)
RPM
4400
3080
2640
Nominal RPM
8800
4400
2200
1100
Time per Revolution
13.64 ms
19.48 ms
22.73 ms
FIGURE 8. 9-bit Temperature-to-Digital Transfer Function
Time per Revolution
13.64 ms
27.27 ms
54.54 ms
6.82 ms
Given Speed in Decimal
15
Counts for “Divide by 2”
Counts for the
temperature. An 8-bit digital comparator is also incorporated
that compares the readings to the user-programmable Hot
and Overtemperature setpoints, and Hysteresis values.
(Default) in Decimal
(maximum counts)
153
153
153
153
153 counts
219 counts
255 counts
70% RPM
10004020
6160
3080
1540
770
Time per Revolution
Typical RPM
for 70% RPM
Comments
70% RPM
60% RPM
19.48 ms
38.96 ms
77.92 ms
9.74 ms
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