peculiarity
2-wire SMBus compatible, serial digital interface
8-bit [Sigma] [Delta] ADC
CCP Display V, 2.5V, 3.3 VSBY, 5.0V, 12V motherboard/processor supplies
Display 2 remote thermal diode
Autonomous programmable fan control, temperature reading
Fan controls temperature readings, noise filtering
Resolution of a 1.0°C digital temperature sensor
3 PWM fan speed control outputs
4 fan tachometer inputs
Monitor 5 VID control line
24-pin QSOP package
XOR tree test mode
illustrate
Hardware monitoring, LM85, two-wire digital interface compatible with SMBus 2.0. Using an 8-bit [Sigma] [Delta] ADC, the LM85 measures:
- the temperature of the transistor where two remote diodes are connected and the die of itself
- V, 2.5V, 3.3VSBY, 5.0V, 12V power supply (internal scaling resistor).
To set the fan speed, the LM85 has three PWM outputs that are controlled by each of the three temperature zones. The LM85 includes a digital filter that can be called for smooth running better control of the temperature reading of the fan speed. The LM85 has 4 tachometer inputs to measure fan speed. Limit and status registers for all measured values are also included.
Main specifications
Voltage measurement accuracy
± 2%FS (max.)
resolution
8 bits, at 1 °C
Temperature sensor accuracy
± 3 °C (max.)
Temperature range
LM85 business
0°C to +85°C
Remote temperature accuracy
0 °C to +125 °C
Supply voltage
is +3.0 V to +3.6 V
Supply current
0.53 mA
apply
Desktop computers
Microprocessor-based devices (e.g. base stations, routers, ATMs, point-of-sale)
Information on the differences between LM85BIMQ and LM85CIMQ can be found in Section 6.0. It is highly recommended that all new designs use the LM85BIMQ.
Date Revised
8/2002 Added LM85BIMQ functional differences and specifications.
3 / 2003 Updated registration 74H, description of tachometer monitoring mode.