User guide

ManualsBrandsRainbow Electronics ManualsSensorsLM63

LM63

1˚C/

3˚C Accurate Remote Diode Digital Temperature

Sensor with Integrated Fan Control

General Description

The LM63 is a remote diode temperature sensor with inte-

grated fan control. The LM63 accurately measures: (1) its

own temperature and (2) the temperature of a diode-

connected transistor, such as a 2N3904, or a thermal diode

commonly found on Computer Processors, Graphics Pro-

cessor Units (GPU) and other ASIC’s. The LM63 remote

temperature sensor’s accuracy is factory trimmed for the

series resistance and 1.0021 non-ideality of the Intel

0.13

µm Pentium

4 and Mobile Pentium 4 Processor-M thermal

diode. The LM63 has an offset register to correct for errors

caused by different non-ideality factors of other thermal di-

odes. For the latest information contact

hardware.monitor.team

nsc.com.

The LM63 also features an integrated, pulse-width-

modulated (PWM), open-drain fan control output. Fan speed

is a combination of the remote temperature reading, the

lookup table and the register settings. The 8-step Lookup

Table enables the user to program a non-linear fan speed vs.

temperature transfer function often used to quiet acoustic

fan noise.

Features

n Accurately senses diode-connected 2N3904 transistors

or thermal diodes on-board large processors or ASIC’s

n Accurately senses its own temperature

n Factory trimmed for Intel Pentium 4 and Mobile Pentium

4 Processor-M thermal diodes

n Integrated PWM fan speed control output

n Acoustic fan noise reduction with User-programmable

8-step Lookup Table

n Multi-function, user-selectable pin for either ALERT

output, or Tachometer input, functions

n Tachometer input for measuring fan RPM

n Offset register can adjust for a variety of thermal diodes

n 10 bit plus sign remote diode temperature data format,

with 0.125˚C resolution

n SMBus 2.0 compatible interface, supports TIMEOUT

n LM86-compatible pinout

n LM86-compatible register set

n 8-pin SOIC package

Key Specifications

Remote Diode Temp Accuracy (with quantization

error)

Ambient

Temp

Diode

Temp

PWML

Max

Version

Max

Error

30 to 50˚C 60 to 100˚C 5 mA LM63C

1.0˚C

30 to 50˚C 60 to 100˚C 5 mA LM63D

3.0˚C

0 to 85˚C 25 to 125˚C 8 mA All

3.0˚C

Local Temp Accuracy (includes quantization error)

Ambient Temp Max Error

25˚C to 125˚C

3.0˚C

Supply Voltage 3.0 V to 3.6 V

Supply Current 1.3 mA (typ)

Applications

n Computer Processor Thermal Management

(Laptop, Desktop, Workstations, Servers)

n Graphics Processor Thermal Management

n Electronic Test Equipment

n Projectors

n Office Equipment

n Industrial Controls

Connection Diagram

20057001

Intel

and Pentium

are registered trademarks of Intel Corporation.

May 2003

LM63

1˚C/

3˚C Accurate Remote Diode Digital Temperature Sensor with Integrated Fan Control

Summary of content (28 pages)

PAGE 1
LM63 ± 1˚C/ ± 3˚C Accurate Remote Diode Digital Temperature Sensor with Integrated Fan Control General Description The LM63 is a remote diode temperature sensor with integrated fan control. The LM63 accurately measures: (1) its own temperature and (2) the temperature of a diodeconnected transistor, such as a 2N3904, or a thermal diode commonly found on Computer Processors, Graphics Processor Units (GPU) and other ASIC’s.
PAGE 2
LM63 Pin Descriptions Pin Name Input/Output Function and Connection 1 VDD Power Supply Input Connect to a low-noise +3.3 ± 0.3 VDC power supply, and bypass to GND with a 0.1 µF ceramic capacitor in parallel with a 100 pF ceramic capacitor. A bulk capacitance of 10 µF needs to be in the vicinity of the LM63’s VDD pin. 2 D+ Analog Input Connect to the anode (positive side) of the remote diode. A 2.2 nF ceramic capacitor must be connected between pins 2 and 3.
PAGE 3
LM63 Typical Application 20057003 Ordering Information Part Description Top Mark Order Number Transport Media LM63C ( ± 1˚C) 8-pin SOIC LM63CIMA LM63CIMAX 2500 Units in Tape and Reel LM63C ( ± 1˚C) 8-pin SOIC LM63CIMA LM63CIMA 95 Units in Rail LM63D ( ± 3˚C) 8-pin SOIC LM63DIMA LM63DIMAX 2500 Units in Tape and Reel LM63D ( ± 3˚C) 8-pin SOIC LM63DIMA LM63DIMA 95 Units in Rail LM63 Evaluation Board With Software and User’s Guide N/A LM63EVAL Packaged 3 www.national.
PAGE 4
LM63 Absolute Maximum Ratings ESD Susceptibility (Note 4) (Notes 1, Human Body Model 2) Supply Voltage, VDD −0.3 V to 6.0 V Voltage on SMBDAT, SMBCLK, ALERT/Tach, PWM Pins −0.5 V to 6.
PAGE 5
LM63 AC Electrical Characteristics The following specifications apply for VDD = 3.0 VDC to 3.6 VDC, and all analog source impedance RS = 50Ω unless otherwise specified in the conditions. Boldface limits apply for TA = TMIN to TMAX; all other limits TA = +25˚C. Limits (Note 8) Units (Limit) Fan Control Accuracy ± 10 % (max) Fan Full-Scale Count 65535 (max) Symbol Parameter Typical (Note 7) Conditions TACHOMETER ACCURACY Fan Counter Clock Frequency 90 kHz Fan Count Update Frequency 1.
PAGE 6
LM63 SMBus Digital Switching Characteristics Unless otherwise noted, these specifications apply for VDD = +3.0 VDC to +3.6 VDC, CL (load capacitance) on output lines = 80 pF. Boldface limits apply for TA = TJ; TMIN ≤ TA ≤ TMAX; all other limits TA = TJ = +25˚C, unless otherwise noted. The switching characteristics of the LM63 fully meet or exceed the published specifications of the SMBus version 2.0.
PAGE 7
Note 2: All voltages are measured with respect to GND, unless otherwise noted. Note 3: When the input voltage (VIN) at any pin exceeds the power supplies (VIN < GND or VIN > V+), the current at that pin should be limited to 5 mA. Parasitic components and/or ESD protection circuitry are shown below for the LM63’s pins. The nominal breakdown voltage of D3 is 6.5 V. Care should be taken not to forward bias the parasitic diode, D1, present on pins D+ and D−.
PAGE 8
LM63 1.0 Functional Description The remote temperature (RT) reading is associated with a T_CRIT Setpoint Register, and both local and remote temperature (LT and RT) readings are associated with a HIGH setpoint register (LHS and RHS). The RT is also associated with a LOW setpoint register (RLS). At the end of every temperature reading a digital comparison determines whether that reading is above its HIGH or T_CRIT setpoint or below its LOW setpoint.
PAGE 9
The SMBus Specifications 1.1 and 2.0 state that in response to and ARA (Alert Response Address) “after acknowledging the slave address the device must disengage its ALERT pulldown”. Furthermore, “if the host still sees ALERT low when the message transfer is complete, it knows to read the ARA again.” This SMBus “disengaging ALERT requirement prevents locking up the SMBus alert line. Competitive parts may address the “disengaging of ALERT” differently than the LM63 or not at all.
PAGE 10
LM63 1.0 Functional Description Local Temperature data is represented by an 8-bit, two’s complement byte with an LSB equal to 1˚C: (Continued) Temperature Digital Output Binary Hex +125˚C 0111 1101 7D +25˚C 0001 1001 19 +1˚C 0000 0001 01 0˚C 0000 0000 00 −1˚C 1111 1111 FF −25˚C 1110 0111 E7 −55˚C 1100 1001 C9 1.6 OPEN-DRAIN OUTPUTS The SMBDAT, ALERT, and PWM outputs are open-drain outputs and do not have internal pull-ups.
PAGE 11
LM63 1.0 Functional Description (Continued) No-Acknowledge from the Master. Note that the NoAcknowledge is typically used as a signal for the slave indicating that the Master has read its last byte. 1.9 DIGITAL FILTER The LM63 incorporates a user-configured digital filter to suppress erroneous Remote Temperature readings due to noise. The filter is accessed in the Remote Diode Temperature Filter and Comparator Mode Register. The filter can be set according to the following table.
PAGE 12
LM63 1.0 Functional Description (Continued) 1.11 ONE-SHOT REGISTER The One-Shot Register is used to initiate a single conversion and comparison cycle when the device is in standby mode, after which the data returns to standby. This is not a data register. A write operation causes the one-shot conversion. The data written to this address is irrelevant and is not stored. A zero will always be read from this register. 1.
PAGE 13
LM63 2.0 LM63 Registers The following pages include: Section 2.1, a Register Map in Hexadecimal Order, which shows a summary of all registers and their bit assignments, Section 2.2, a Register Map in Functional Order, and Section 2.3, a detailed explanation of each register. Do not address the unused or manufacturer’s test registers. 2.1 LM63 REGISTER MAP IN HEXADECIMAL ORDER The following is a Register Map grouped in hexadecimal address order.
PAGE 14
LM63 2.0 LM63 Registers Register 0x[HEX] Register Name 4F Lookup Table Hystersis 50–5F Lookup Table 60–BE [Reserved] BF Rmt Diode Temp Filter C0–FD [Reserved] (Continued) DATA BITS D7 D6 D5 D4 D3 D2 D1 D0 0 0 0 LOOKH4 LOOKH3 LOOKH2 LOOKH1 LOOKH0 Lookup Table of up to 8 PWM and Temp Pairs in 8-bit Registers Not Used 0 0 0 0 0 RDTF1 RDTF0 ALTCOMP Not Used FE Manufacturer’s ID 0 0 0 0 0 0 0 1 FF Stepping/Die Rev. ID 0 1 0 0 0 0 0 1 2.
PAGE 15
Register [HEX] LM63 2.0 LM63 Registers (Continued) Register Name Read/Write POR Default [HEX] ALERT STATUS AND MASK REGISTERS 02 ALERT Status Read Only N/A 16 ALERT Mask R/W A4 Read Only 41 ID AND TEST REGISTERS FF Stepping/Die Rev.
PAGE 16
LM63 2.0 LM63 Registers (Continued) LM63 Register Descriptions In Functional Order Fan Control Registers Address Hex Read/ Write Bits POR Value Name Description 4AHEX FAN PWM AND TACHOMETER CONFIGURATION REGISTER 7:6 4A R/W 00 These bits are unused and always set to 0. 5 1 0: the PWM Value (register 4C) and the Lookup Table (50–5F) are read-only. The PWM value (0 to 100%) is determined by the current remote diode temperature and the Lookup Table, and can be read from the PWM value register.
PAGE 17
(Continued) Fan Control Registers Address Hex Read/ Write Bits LM63 2.0 LM63 Registers POR Value (Continued) Name Description 4BHEX FAN PWM AND TACHOMETER CONFIGURATION REGISTER 7:6 5 4B 0 These bits are unused and always set to 0 1 If 0, the fan spin-up uses the duty cycle and spin-up time, bits 0–4.
PAGE 18
LM63 2.0 LM63 Registers (Continued) Fan Control Registers Address Hex Read/ Write Bits (Continued) POR Value Name Description 50HEX to 5FHEX LOOKUP TABLE (7 Bits for Temperature and 6 Bits for PWM for each Temperature/PWM Pair) 50 51 52 53 54 55 56 57 58 Read. (Write only if reg 4A bit 5 = 1.
PAGE 19
LM63 2.0 LM63 Registers (Continued) Configuration Register ADDRESS Hex Read/ Write Bits POR Value Name Description 03 (09)HEX CONFIGURATION REGISTER 7 6 03 (09) 0 ALERT Mask When this bit is a 0, ALERT interrupts are enabled. When this bit is set to a 1, ALERT interrupts are masked, and the ALERT pin is always in a high impedance (open) state. When this bit is a 0, the LM63 is in operational mode, converting, comparing, and updating the PWM output continuously.
PAGE 20
LM63 2.0 LM63 Registers (Continued) Tachometer Count And Limit Registers ADDRESS Read/ Hex Write Bits POR Value Name Description 47HEX TACHOMETER COUNT (MSB) and 46HEX TACHOMETER COUNT (LSB) REGISTERS (16 bits: Read LSB first to lock MSB and ensure MSB and LSB are from the same reading) 47 Read Only 7:0 N/A Tachometer Count (MSB) Read Only 7:2 N/A Tachometer Count (LSB) These registers contain the current 16-bit Tachometer Count, representing the period of time between tach pulses.
PAGE 21
LM63 2.0 LM63 Registers (Continued) Remote Diode Temperature, Offset And Setpoint Registers ADDRESS Hex Read/ Write 01 Read Only 10 Read Only 11 R/W 12 R/W 07 (0D) R/W 13 R/W 08 (0E) R/W 14 R/W Bits 7:0 POR Value Name Description N/A Remote Diode Temperature Reading (MSB) This is the MSB of the 2’s complement value, representing the temperature of the remote diode connected to the LM63. Bit 7 is the sign bit, bit 6 has a weight of 0x40 (64˚), and bit 0 has a weight of 1˚C.
PAGE 22
LM63 2.0 LM63 Registers (Continued) ALERT Status And Mask Registers ADDRESS Hex Read/ Write Bits POR Value Name Description 02HEX ALERT STATUS REGISTER (8-bits) (All Alarms are latched until read, then cleared if alarm condition was removed at the time of the read.) 0 Busy When this bit is a 0, the ADC is not converting. When this bit is set to a 1, the ADC is performing a conversion. This bit does not affect ALERT status.
PAGE 23
LM63 2.0 LM63 Registers (Continued) ALERT Status And Mask Registers ADDRESS Hex Read/ Write Bits POR Value (Continued) Name Description 16HEX ALERT MASK REGISTER (8-bits) 7 16 R/W 1 This bit is unused and always read as 1. Local High Alarm Mask When this bit is a 0, a Local High Alarm event will generate an ALERT.
PAGE 24
LM63 3.0 Application Notes 3.1 FAN CONTROL DUTY CYCLE VS. REGISTER SETTINGS AND FREQUENCY PWM Freq 4D [4:0] Step Resolution, % PWM Value 4D [5:0] for 100% PWM Value 4C [5:0] for about 75% 0 PWM Value 4C [5:0] for 50% PWM Freq at 360 kHz Internal Clock, kHz PWM Freq at 1.4 kHz Internal Clock, Hz Actual Duty Cycle, % When 75% is Selected Address 0 is mapped to Address 1 1 50 2 1 1 180.0 703.1 50.0 2 25 4 3 2 90.00 351.6 75.0 3 16.7 6 5 3 60.00 234.4 83.3 4 12.
PAGE 25
The LM63 has been optimized for use with the thermal diode on the die of an Intel Pentium 4 or a Mobile Pentium 4 Processor-M processor. A discrete diode can also be used to sense the temperature of external objects or ambient air. Remember that a discrete diode’s temperature will be affected, and often dominated by, the temperature of its leads. Most silicon diodes do not lend themselves well to this application. It is recommended that a diode-connected 2N3904 transistor be used.
PAGE 26
LM63 3.0 Application Notes 3.4 COMPUTING RPM OF THE FAN FROM THE TACH COUNT (Continued) Pentium 4 processor’s thermal diode. The non-ideality factor, η, is the only other parameter not accounted for and depends on the diode that is used for measurement. Since ∆Vbe is proportional to both η and T, the variations in η cannot be distinguished from variations in temperature. Since the temperature sensor does not control the nonideality factor, it will directly add to the inaccuracy of the sensor.
PAGE 27
guard should not be between the D+ and D− lines. In the event that noise does couple to the diode lines it would be ideal if it is coupled common mode. That is equally to the D+ and D− lines. (Continued) 3.5 PCB LAYOUT FOR MINIMIZING NOISE 4. Avoid routing diode traces in close proximity to power supply switching or filtering inductors. 5. Avoid running diode traces close to or parallel to high speed digital and bus lines.
PAGE 28
LM63 ± 1˚C/ ± 3˚C Accurate Remote Diode Digital Temperature Sensor with Integrated Fan Control Physical Dimensions inches (millimeters) unless otherwise noted 8-Lead (0.