Features: ·Remote diode temperature sensing (2 channels)
· 8 positive voltage inputs with scaling resistors for monitoring +5 V, +12 V, +3.3 V, +2.5 V, Vccp power supplies directly
· 2 inputs selectable for fan speed or voltage monitoring
·8-bit DAC output for controlling fan speed
· Chassis Intrusion Detector input
·WATCHDOG comparison of all monitored values
· SMBus or I2C Serial Bus interface compatibility
· VID0-VID4 or IRQ0-IRQ4 monitoring inputs
· On chip temperature sensorApplication· System Thermal and Hardware Monitoring for Servers, Workstations and PCs
· Networking and Telecom Equipment
·Office Electronics
· Electronic Test Equipment and Instrumentation
Specifications
| Temp Resolution |
8-bit/1degC |
| Remote Diode Thermal Sensors |
2 |
| TruTherm(TM) Beta Compensation |
No |
| Analog Inputs |
7 to 3, V+ |
| ADC Resolution |
8 bits |
| Fan Speed Inputs |
4 |
| Fan Control Output(s) |
1 DAC |
| Fan Control Method |
Undefined |
| VID Inputs |
5 |
| Dynamic VID VCCP Monitoring |
Undefined |
| Bidirectional PROCHOT Support |
Undefined |
| GPIOs |
CI, RESET |
| Interrupt Outputs |
1 |
| Reference Voltage |
Undefined |
| Temperature Accuracy (+/-) |
4 deg C |
| Temperature Min |
-40 deg C |
| Temperature Max |
125 deg C |
| Interface Type |
2-Wire Serial |
| Supply Min |
2.8 Volt |
| Supply Max |
3.8 Volt |
| Quiescent Current |
2 mA |
| Resolution |
8 bits |
| Temperature Accuracy (+/-) |
3 deg C |
| Automotive Selection Guide |
Yes |
| PowerWise |
Yes |
| View Using Catalog |
Positive Supply Voltage (V+) ..............................................................+6.0 V
Voltage on Any Input or Output Pin:
+12Vin .................................................................................−0.3 V to +18 V
ADD/NTESTOUT, .............................................................................−0.3 V to
DACOut/NTEST_IN, AIN1, AIN2 ....................................................(V++ 0.3 V)
All other pins ..........................................................................−0.3 V to +6 V
Input Current at any Pin (Note 4) .......................................................±5 mA
Package Input Current (Note 4) ........................................................±20 mA
Maximum Junction Temperature
(TJ max) ..............................................................................................150 °C
ESD Susceptibility (Note 6)
Human Body Model ..............................................................................2500 V
Machine Model ........................................................................................150V
Soldering Information
MTC Package (Note 7) :
Vapor Phase (60 seconds) ..................................................................215 °C
Infrared (15 seconds) .........................................................................235 °C
Storage Temperature .....................................................−65 °C to +150 °CDescriptionThe LM87 is a highly integrated data acquisition system for hardware monitoring of servers, Personal Computers, or virtually any microprocessor-based system. In a PC, the LM87 can be used to monitor power supply voltages, motherboard and processor temperatures, and fan speeds. Actual values for these inputs can be read at any time. Programmable WATCHDOG limits in the LM87 activate a fully programmable and maskable interrupt system with two outputs (INT# and THERM#).
The LM87 has an on-chip digital output temperature sensor with 8-bit resolution as well as the capability of monitoring 2 external diode temperatures to 8-bit resolution, an 8 channel analog input ADC with 8-bit resolution and an 8-bit DAC. A channel on the ADC measures the supply voltage applied to the LM87, nominally 3.3 V. Two of the ADC inputs can be redirected to a counter that can measure the speed of up to 2 fans. A slow speed [Sigma][Delta] ADC architecture allows stable measurement of signals in an extremely noisy environment. The DAC, with a 0 to 2.5 V output voltage range, can be used for fan speed control. Additional inputs are provided for Chassis Intrusion detection circuits, and VID monitor inputs. The VID monitor inputs can also be used as IRQ inputs if VID monitoring is not required. The LM87 has a Serial Bus interface that is compatible with SMBus™ and I2C™.
Reliability Metrics
| Part Number |
Process |
EFR Reject |
EFR Sample Size |
PPM |
LTA Rejects |
LTA Device Hours |
FITS |
MTTF (Hours) |
| LM87CIMT |
CS065 |
2 |
34108 |
59 |
0 |
3862000 |
1 |
1095853045 |
| LM87CIMTX |
CS065 |
2 |
34108 |
59 |
0 |
3862000 |
1 |
1095853045 |
Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR. The Long Term Failure Rates were calculated at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress temperature of 150°C to an application temperature of 55°C.For more information on Reliability Metrics, please click here.
Design Tools
| Title |
Size in Kbytes |
Date |
|
|
|
| LMxx - Windows 95/98 VXD drivers with stand alone application for talking to temperature sensors or hardware monitors on a mother board |
1366 Kbytes |
28-Jul-2003 |
View |
Download |
|
If you have trouble printing or viewing PDF file(s), see Printing Problems.
|
More Application Notes
| Title |
Size in Kbytes |
Date |
|
| AN-1155: Application Note 1155 A Simple Software I2C Routine for the COP8 |
82 Kbytes |
15-May-04 |
Download |
| AN-1260: Application Note 1260 Autonomous Fan Control for Processor Systems Using the LM85 |
74 Kbytes |
10-Mar-04 |
Download |
| AN-1262: Application Note 1262 Four-Speed Fan Control Using Simple Remote Diode Temperature Sensor |
70 Kbytes |
1-Oct-02 |
Download |
If you have trouble printing or viewing PDF file(s), see Printing Problems.
|
LM87 Data Sheet
