ADT7467 Analog Devices, Inc., ADT7467 Datasheet
ADT7467
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ADT7467 Summary of contents
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... The ADT7467 dBCool controller is a thermal monitor and multiple PWM fan controller for noise-sensitive or power- sensitive applications requiring active system cooling. The ADT7467 can drive a fan using either a low or high frequency drive signal, monitor the temperature two remote sensor diodes plus its own internal temperature, and measure and control the speed four fans so that they operate at the lowest possible speed for minimum acoustic noise ...
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... Revision History ............................................................................... 2 Specifications..................................................................................... 3 Absolute Maximum Ratings............................................................ 5 Thermal Characteristics .............................................................. 5 ESD Caution.................................................................................. 5 Pin Configuration and Function Descriptions............................. 6 Typical Performance Characteristics ............................................. 7 Product Description......................................................................... 9 Comparison Between ADT7460 and ADT7467 ...................... 9 Recommended Implementation............................................... 10 Serial Bus Interface......................................................................... 11 Write Operations ........................................................................ 13 Read Operations ......................................................................... 13 SMBus Timeout .......................................................................... 14 Analog-to-Digital Converter ........................................................ 15 Voltage Measurement Input...................................................... 15 Additional ADC Functions for Voltage Measurements ...
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... RPM 85.5 90 94.5 kHz 83.7 90 96.3 kHz kHz Rev. A| Page ADT7467 = 25°C and represent most likely parametric A . Timing specifications are tested at MIN Test Conditions/Comments Interface inactive, ADC active Standby mode 0°C ≤ T ≤ 70°C A −40°C ≤ T ≤ +100°C A −40°C ≤ T ≤ ...
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... ADT7467 Parameter OPEN-DRAIN DIGITAL OUTPUTS, PWM1 to PWM3, XTO Current Sink Output Low Voltage High Level Output Current OPEN-DRAIN SERIAL DATA BUS OUTPUT (SDA) Output Low Voltage High Level Output Current SMBus DIGITAL INPUTS (SCL, SDA) Input High Voltage, V ...
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... Exposure to absolute 150°C maximum rating conditions for extended periods may affect −65°C to +150°C device reliability. 220°C THERMAL CHARACTERISTICS 260°C 300°C 16-lead QSOP package: 1000 V θ = 150°C/W JA θ = 39°C/W JC Rev. A| Page ADT7467 ...
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... V Power Supply. Can be powered by 3.3 V standby if monitoring in low power states is required through this pin. The ADT7467 can also be powered from supply. Setting Bit 7 of Configuration Register 1 (Reg. 0x40) rescales the V 4 TACH3 Digital Input (Open Drain). Fan tachometer input to measure speed of Fan 3. Can be reconfigured as an analog input (AIN3) to measure the speed of 2-wire fans (low frequency mode only) ...
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... Figure 8. Remote Temperature Error vs. Differential Mode Noise Frequency 1.40 1.35 1.30 1.25 1.20 1.15 1.10 1.05 20 100 Rev. A| Page 100mV 40mV 60mV 10 100 1M 10M 100M FREQUENCY (kHz) 20mV 10mV 10 100 1M 10M 100M FREQUENCY (kHz) 3.0 3.2 3.4 3.6 3.8 4.0 4.2 4.4 4.6 4.8 5.0 POWER SUPPLY VOLTAGE (V) Figure 9. Normal I vs. Power Supply DD ADT7467 1G 1G 5.2 5.4 ...
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... TEMPERATURE (°C) Figure 13. Internal Temperature Error vs. ADT7467 Temperature 1.0 0.5 0 –0.5 –1.0 –1.5 –2.0 –2.5 –3.0 –3.5 –4.0 –40 – TEMPERATURE (°C) Figure 14. Remote Temperature Error vs. ADT7467 Temperature 100 120 100 120 ...
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... THERM limit (100°C), the fans run at full speed. Fail-safe cooling is also provided 4.6 sec after V up. The fans operate at full speed if the ADT7467 has not been addressed via the SMBus within 4.6 sec of when the V is powered up. This protects the system in the event CCP that the SMBus fails ...
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... ADT7467 Configuration Register 5 Bit 0: If Bit 0 is set to 1, the ADT7467, in terms of temperature, is backward compatible with the ADT7460. Measurements, including T calibration circuit and fan control, work in the MIN range −127°C to +127°C. Also, care should be taken in reprogramming the temperature limits (T THERM ) to their desired twos complement value, because the power-on default for them is at Offset 64 ...
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... ADT7467 is connected to this bus as a slave device under the control of a master controller, which is usually (but not necessarily) the ICH. The ADT7467 has a fixed 7-bit serial bus address of 0101110 or 0x2E. The read/write bit must be added to get the 8-bit address (01011100 or 0x5C). Data is sent over the serial bus in sequences of nine clock pulses: eight bits of data followed by an acknowledge bit from the slave device ...
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... ACK. BY ADT7467 FRAME 2 ADDRESS POINTER REGISTER BYTE STOP BY ACK. BY ADT7467 MASTER FRAME 3 DATA BYTE ACK. BY ADT7467 FRAME ACK. BY MASTER FRAME 2 DATA BYTE FROM ADT7467 STOP BY MASTER STOP BY MASTER ...
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... P 6. The master asserts a stop condition on SDA, and the transaction ends. In the ADT7467, the receive byte protocol is used to read a single byte of data from a register whose address has previously been set by a send byte or write byte operation. This operation is illustrated in Figure 21. ...
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... SMBALERT is cleared only if the error condition is absent. SMBUS TIMEOUT The ADT7467 includes an SMBus timeout feature. If there is no SMBus activity for 35 ms, the ADT7467 assumes that the bus is locked and releases the bus. This prevents the device from locking or holding the SMBus in anticipation of receiving data. Some SMBus controllers cannot handle the SMBus timeout feature can be disabled ...
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... CCP ADDITIONAL ADC FUNCTIONS FOR VOLTAGE MEASUREMENTS A number of other functions are available on the ADT7467 to offer the system designer increased flexibility. Turn-Off Averaging For each voltage measurement read from a value register, 16 readings are made internally, the results of which are averaged ...
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... BE current. Unfortunately, this technique requires calibration to null the effect of the absolute value of V each device. The technique used in the ADT7467 is to measure the change in V when the device is operated at three currents. Previous BE devices have used only two operating currents, but the use of a third current allows automatic cancellation of resistances in series with the external temperature sensor ...
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... D– input and the emitter is connected to the D+ input NPN transistor is used, the emitter is connected to the D– input and the base is connected to the D+ input. Figure 25 and Figure 26 show how to connect the ADT7467 to an NPN or PNP transistor for temperature measurement. To prevent ground noise from interfering with the measurement, ...
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... The high current level of the ADT7467 μA, and the low level current, I HIGH is 6 μA. If the ADT7467 current levels do not match the current levels specified by the CPU manufacturer, it might be necessary to remove an offset. The CPU’s data sheet should provide information relating to n differences ...
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... D+/D– lines. Constant high frequency noise usually attenuates or increases temperature measurements by a linear, constant value. The ADT7467 has temperature offset registers at Addresses 0x70 and 0x72 for the Remote 1 and Remote 2 temperature channels. By performing a one-time calibration of the system, the user can determine the offset caused by system board noise and null it using the offset registers ...
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... Reg. 0x53 Remote 2 temperature high limit = 0x7F default Reading Temperature from the ADT7467 It is important to note that temperature can be read from the ADT7467 as an 8-bit value (with 1°C resolution 10-bit value (with 0.25°C resolution). If only 1°C resolution is required, the temperature readings can be read at any time and in no particular order ...
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... Alternatively, SMBALERT interrupts can be generated to flag a processor or microcontroller of out-of-limit conditions. 8-Bit Limits The following is a list of 8-bit limits on the ADT7467. Voltage Limit Registers Reg. 0x46 V low limit = 0x00 default CCP Reg ...
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... The total monitoring cycle time for voltage and temperature monitoring with averaging disabled is 19 ms. The ADT7467 is a derivative of the ADT7468 result, the total conversion time for the ADT7467 and ADT7468 are the same, even though the ADT7467 has less monitored channels ...
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... CLEARED ON READ Register (TEMP BELOW LIMIT) Configuration Register 3 (Reg. 0x78) Assigning THERM Functionality to a Pin Pin 9 on the ADT7467 has four possible functions: SMBALERT , INTERRUPT MASK BIT CLEARED THERM , GPIO, and TACH4. The user chooses the required (SMBALERT REARMED) functionality by setting Bit 0 and Bit 1 of Configuration Register 4 at Address 0x7D ...
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... ADT7467 The user can also set up the ADT7467 so that when the THERM pin is driven low externally, the fans run at 100%. The fans run at 100% for the duration of the time that the THERM pin is pulled low. This is done by setting the BOOST bit (Bit 2) in Configuration Register 3 (Address 0x78 ...
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... Generating SMBALERT Interrupts from THERM Timer Events The ADT7467 can generate SMBALERT s when a programma- ble THERM timer limit has been exceeded. This allows the system designer to ignore brief, infrequent THERM assertions while capturing longer THERM timer events. Register 0x7A is the THERM timer limit register. This 8-bit register allows a limit from 0 sec (first THERM assertion ...
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... Configuring the THERM Pin as an Output In addition to monitoring THERM as an input, the ADT7467 can optionally drive THERM low as an output. In cases where PROCHOT is bidirectional, THERM can be used to throttle the processor by asserting PROCHOT . The user can preprogram system-critical thermal limits. If the temperature exceeds a thermal limit by 0.25° ...
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... In many cases, the 4-wire fan PWM input has a built-in pull-up resistor. The ADT7467 PWM frequency can be set to a selection of low frequencies or a single high PWM frequency. The low frequency options are usually used for 2-wire and 3-wire fans, and the high frequency option is usually used for 4-wire fans ...
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... Driving 2-Wire Fans The ADT7467 can only support 2-wire fans when low frequency PWM mode is selected in Configuration Register 5, Bit 2. If this bit is not set to 1, the ADT7467 cannot measure the speed of 2-wire fans. Figure 39 shows how a 2-wire fan can be connected to the ADT7467 ...
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... TACH Inputs When configured as TACH inputs, Pins and 9 are open- drain TACH inputs intended for fan speed measurement. Signal conditioning in the ADT7467 accommodates the slow rise and fall times typical of fan tachometer outputs. The 1N4148 maximum input signal range even when V than 5 V ...
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... Reg. 0x2E TACH4 low byte = 0x00 default COUNTER ADT7467 Reg. 0x2F TACH4 high byte = 0x00 default Reading Fan Speed from the ADT7467 or Totem-Pole Output, CC The measurement of fan speeds involves a 2-register read for each measurement. The low byte should be read first. This freezes the high byte until both high and low byte registers are read, preventing erroneous TACH readings ...
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... Fan Speed Measurements (Low Frequency Mode Only) The ADT7467 is capable of measuring the speed of 2-wire fans, that is, fans without TACH outputs this, the fan must be interfaced as shown in the Driving 2-Wire Fans section. In this case, the TACH inputs should be reprogrammed as analog inputs, AIN ...
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... FAN SPIN-UP The ADT7467 has a unique fan spin-up function. It spins the fan at 100% PWM duty cycle until two TACH pulses are de- tected on the TACH input. Then, the PWM duty cycle goes to the expected running value, for example, 33%. The advantage is that fans have different spin-up characteristics and take different times to overcome inertia ...
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... Automatic Fan MIN Control Overview section. In manual fan speed control mode, the ADT7467 allows the duty cycle of any PWM output to be manually adjusted. This can be useful if the user wants to change fan speed in software or adjust PWM duty cycle output for test purposes. Bits <7:5> ...
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... Likewise, MIN If V goes high (the system processor power rail is powered CC up), a fail-safe timer begins to count down. If the ADT7467 is not addressed by a valid SMBus transaction before the fail-safe CCP timeout (4.6 sec) lapses, the ADT7467 drives the fans to full CCP speed ...
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... PWM outputs. The three PWM outputs can be used to control up to four fans. The ADT7467 allows the speed of four fans to be monitored. Each temperature channel has a thermal calibration block, allowing the designer to individually configure the thermal characteristics of each temperature channel ...
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... ADT7467 DYNAMIC T CONTROL MODE MIN In addition to the automatic fan speed control mode, the ADT7467 has a mode that extends the basic automatic fan speed control loop. Dynamic T control allows the ADT7467 MIN to intelligently adapt the system’s cooling solution to optimize system performance or system acoustics, depending on user or design requirements ...
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... Therefore, instead of designing for the worst case, the system thermals can be defined as operating zones. ADT7467 can self-adjust its fan control loop to maintain either an operating zone temperature or a system target temperature. For example, users can specify that the ambient temperature in a system be maintained at 50° ...
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... This influences the choice of whether to use the TACH4 pin or to reconfigure it for the THERM function. 3. Will the CPU fan be controlled using the ADT7467, or will it run at full speed 100% of the time? Running it at 100% frees up a PWM output, but the system is louder ...
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... Recommended Implementation Configuring the ADT7467 as in Figure 54 provides the system designer with the following features: 1. Two PWM outputs for control three fans. (The front and rear chassis fans are connected in parallel.) 2. Three TACH fan speed measurement inputs measured internally through Pin 4. ...
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... ADT7467 STEP 2: CONFIGURING THE MUX After the system hardware configuration is determined, the fans can be assigned to particular temperature channels. Not only can fans be assigned to individual channels, but the behavior of the fans is also configurable. For example, fans can run using automatic fan control, can run manually (using software control), or can run at the fastest speed calculated by multiple temperature channels ...
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... Mux Configuration Example This is an example of how to configure the mux in a system using the ADT7467 to control three fans. The CPU fan sink is controlled by PWM1, the front chassis fan is controlled by PWM2, and the rear chassis fan is controlled by PWM3. The mux is configured for the following fan control behavior: • ...
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... ADT7467 STEP 3: T SETTINGS FOR THERMAL MIN CALIBRATION CHANNELS T is the temperature at which the fans start to turn on when MIN using automatic fan control mode. The speed at which the fan runs programmed later. The T MIN temperature-channel specific, for example, 25°C for ambient channel, 30° ...
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... MIN register is given by MIN /0.39 MIN Registers = × fanspeed PWM duty cycle 10 FOR PWM (FAN) OUTPUTS MAX is the maximum duty cycle that each fan in the MAX limit for each fan channel. The default value MAX ADT7467 should be as ...
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... PWM duty cycle.) 3. Determine the slope of the required control loop to meet these requirements. 4. The ADT7467 evaluation software can graphically program and visualize this functionality. Ask your local Analog Devices sales representative for details. Rev Page FOR TEMPERATURE CHANNELS RANGE ...
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... RANGE value for each RANGE Value RANGE 1 T (°C) RANGE 2 2 13. 26.67 32 (default) 40 53. RANGE . RANGE . RANGE Function RANGE MAX MIN RANGE is equal to 33% MIN ADT7467 = RANGE /170 RANGE = RANGE /170 RANGE ) RANGE (1) ...
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... T 20°C 26.6°C This example uses the mux configuration described in the 32°C 40°C Step 2: Configuring the Mux section, with the ADT7467 53.3°C connected as shown in Figure 56. Both CPU temperature and 80°C 100 120 VRM temperature drive the CPU fan connected to PWM1. ...
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... Rev. A| Page minus hysteresis, where hysteresis is the number THERM limit should be considered the maximum worst-case limit runs all fans at 100%, it has significant negative limits are nonmaskable and affect the fan THERM (the temperature at which MAX to that limit (for THERM ADT7467 RANGE ...
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... ADT7467 100 THERMAL CALIBRATION T THERMAL CALIBRATION REMOTE 2 = CPU TEMP T LOCAL = THERMAL CALIBRATION VRM TEMP T REMOTE 1 = AMBIENT TEMP STEP 8: T FOR TEMPERATURE CHANNELS HYST T is the amount of extra cooling a fan provides after the HYST temperature measured drops below T MIN off. The premise for temperature hysteresis (T ...
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... Rev. A| Page PWM CONFIG RAMP PWM PWM1 GENERATOR TACH1 PWM CPU FAN SINK CONFIG RAMP PWM PWM2 GENERATOR TACH2 PWM CONFIG FRONT CHASSIS RAMP PWM PWM3 GENERATOR TACH3 AND 4 REAR CHASSIS − MIN HYST − MIN HYST − MIN HYST ADT7467 ...
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... The hotter each zone is allowed to be, the more quiet the system, because the fans are not required to run as fast. The ADT7467 increases or decreases fan speeds as necessary to maintain the operating point temperature, allowing for system-to-system variations and eliminating the need to design for the worst case ...
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... MIN Short Cycle and Long Cycle The ADT7467 implements two loops: a short cycle and a long cycle. The short cycle takes place every n monitoring cycles. The long cycle takes place every 2n monitoring cycles. The value programmable for each temperature channel. The bits are located at the following register locations: Remote 1 = CYR1 = Bits < ...
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... ADT7467 WAIT 2n MONITORING CYCLES CURRENT TEMPERATURE MEASUREMENT T1(n) YES IS T1(n) > OP1 OPERATING POINT TEMPERATURE NO OP1 IS T1(n) < LOW TEMP LIMIT AND T < HIGH TEMP LIMIT YES MIN AND T < OP1 MIN AND T1(n) > T MIN NO Figure 71. Long Cycle Steps The following examples illustrate circumstances that might cause T to increase, decrease, or stay the same ...
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... The operating point for the processor can be determined by allowing the current temperature to be copied to the operating point register when the PROCHOT output pulls the THERM input low on the ADT7467. This reveals the maximum control is MIN temperature at which the Pentium 4 can run before clock modulation occurs ...
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... ADT7467 Enabling the THERM Trip Point as the Operating Point Bits <4:2> of the dynamic T control Register 1 (Reg. 0x36) MIN enable/disable THERM monitoring to program the operating point. Dynamic T Control Register 1 (0x36) MIN <2> PHTR2 = 1 copies the Remote 2 current temperature to the Remote 2 operating point register if THERM is asserted. The operating point contains the temperature at which THERM is asserted ...
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... This can be tested by putting the ADT7467 into manual mode and changing the PWM output from 0% to 100% PWM duty cycle. The PWM output takes 35 sec to reach 100% when a ramp rate of 1 time slot is selected. Figure 76 shows remote temperature plotted against PWM duty cycle for enhanced acoustics mode ...
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... Figure 80. Fan Reaction to Temperature Variation in Enhanced Acoustics Mode Slower Ramp Rates The ADT7467 can be programmed for much longer ramp times by slowing the ramp rates. Each ramp rate can be slowed by a factor of 4. PWM1 Configuration Register (Reg. 0x5C) <3> SLOW, a setting of 1 slows the ramp rate for PWM1 by 4. ...
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... AMBIENT TEMP Figure 81. Acoustic Enhancement Smoothes Fan Speed Variations in Automatic Fan Speed Control ACOUSTIC ENHANCEMENT MODE OVERVIEW Figure 81 shows a top-level overview of the ADT7467 automatic fan control circuitry and where acoustic enhancement fits in. Acoustic enhancement is intended as a postdesign tweak made by a system or mechanical engineer evaluating the best settings for the system ...
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... Approaches to System Acoustic Enhancement There are two different approaches to implementing system acoustic enhancement: temperature-centric and fan-centric. The ADT7467 uses the fan-centric approach. The temperature-centric approach involves smoothing transient temperatures as they are measured by a temperature source (for example, Remote 1 temperature). The temperature values used to calculate the PWM duty cycle values are smoothed, reducing fan speed variation ...
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... REGISTER MAP Table 17. ADT7467 Registers Address R/W Description 0x21 R V reading CCP 0x22 R V reading CC 0x25 R Remote 1 temperature 0x26 R Local temperature 0x27 R Remote 2 temperature 0x28 R TACH1 low byte 0x29 R TACH1 high byte 0x2A R TACH2 low byte 0x2B R TACH2 high byte 0x2C R TACH3 low byte ...
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... ADT7467 Address R/W Description 0x54 R/W TACH1 minimum low byte 0x55 R/W TACH1 minimum high byte 0x56 R/W TACH2 minimum low byte 0x57 R/W TACH2 minimum high byte 0x58 R/W TACH3 minimum low byte 0x59 R/W TACH3 minimum high byte 0x5A R/W TACH4 minimum low byte 0x5B R/W TACH4 minimum ...
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... Failed (internal circuitry destroyed). • Not populated. (The ADT7467 expects to see a fan connected to each TACH fan is not connected to a TACH, the minimum high and low bytes of that TACH should be set to 0xFFFF.) • Alternate function (for example, TACH4 reconfigured as THERM pin). ...
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... These registers reflect the PWM duty cycle driving each fan at any given time. When in automatic fan speed control mode, the ADT7467 reports the PWM duty cycles through these registers. The PWM duty cycle values vary according to the temperature in automatic fan speed control mode. During fan start-up, these registers report 0x00 ...
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... MIN MIN control on the Remote 2 temperature channel. The chosen T MIN control. The T value chosen is not adjusted, and the channel behaves as MIN MIN Rev Page ADT7467 1 Control Register 2 MIN ) drops below its V CCP LO limit. CCP value is dynamically MIN ...
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... ADT7467 Table 24. Register 0x37—Dynamic T MIN Bit Name R/W Description <2:0> CYR1 Read/write 3-bit Remote 1 cycle value. These three bits define the delay time, in terms of the number of monitoring cycles, for making subsequent T associated with thermal time constants that must be found to optimize the response of the fans and the control loop ...
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... ADT7467 is powered down and powered up again. This prevents rogue programs such as viruses from modifying critical system limit settings. (Lockable) <2> RDY Read only This bit is only set the ADT7467 to indicate that the device is fully powered up and ready to begin system monitoring. <3> FSPD Read/write When set to 1, this bit runs all fans at full speed. Power-on default = 0. This bit cannot be locked at any time. < ...
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... ADT7467 Table 28. Register 0x42—Interrupt Status Register 2 (Power-On Default = 0x00) Bit Name R/W Description <1> OVT Read only OVT = 1 indicates that one of the THERM overtemperature limits has been exceeded. This bit is cleared upon a read of the status register when the temperature drops below THERM –T < ...
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... Remote 2 temperature controls PWMx. 110 = fastest speed calculated by all three temperature channel controls PWMx. 111 = manual mode. PWM duty cycle registers (Reg. 0x30 to Reg. 0x32) become writable. Rev Page ADT7467 Power-On Default 0x82 0x82 ...
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... ADT7467 Table 34. TEMP T /PWM Frequency Registers RANGE 1 Register Address R/W 0x5F Read/write 0x60 Read/write 0x61 Read/write Bit Name R/W <2:0> FREQ Read/write <3> THRM Read/write <7:4> RANGE Read/write 1 These registers become read-only registers when the Configuration Register 1 lock bit is set to 1. Any subsequent attempts to write to these registers fail. ...
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... SYNC = 0 synchronizes only TACH3 and TACH4 to PWM3 output. <5> MIN1 Read/write When the ADT7467 is in automatic fan control mode, this bit defines whether PWM1 is off (0% duty cycle PWM1 minimum duty cycle when the controlling temperature is below its duty cycle below PWM1 minimum duty cycle below T < ...
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... Register Address R/W 0x64 Read/write 0x65 Read/write 0x66 Read/write Bit Name R/W <7:0> PWM duty cycle Read/write 1 These registers become read-only registers when the ADT7467 is in automatic fan control mode. 1 Table 38. T Registers MIN 2 Register Address R/W 0x67 Read/write 0x68 Read/write 0x69 Read/write 1 These are the T registers for each temperature channel ...
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... Remote 1 temperature reading. This is to compensate for any inherent system offsets such as PCB trace resistance. LSB value = 0.5°C. Rev Page ADT7467 Power-On Default 0x64 (100°C) 0x64 (100°C) 0x64 (100°C) Power-On Default 0x44 control loops ...
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... ATTN = 1, the ADT7467 removes the attenuators from the V can be used for other functions such as connecting external sensors. CONV = 1, the ADT7467 is put into a single-channel ADC conversion mode. In this mode, the ADT7467 can be set to read continuously from one input only, for example, Remote 1 temperature. The appropriate ADC channel is selected by writing to bits < ...
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... Remote 1 temperature LSBs. Holds the 2 LSBs of the 10-bit Remote 1 temperature measurement. Local temperature LSBs. Holds the 2 LSBs of the 10-bit local temperature measurement. Remote 2 temperature LSBs. Holds the 2 LSBs of the 10-bit Remote 2 temperature measurement. Rev Page channel. CCP channel. CC measurement. CCP measurement. CC ADT7467 ...
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... ADT7467 Table 50. Register 0x78—Configuration Register 3 (Power-On Default = 0x00) 1 Bit Name R/W <0> ALERT Read/write <1> THERM Read/write <2> BOOST Read/write <3> FAST Read/write <4> DC1 Read/write <5> DC2 Read/write <6> DC3 Read/write <7> DC4 Read/write 1 This register becomes a read-only register when the Configuration Register 1 lock bit is set to 1. Any subsequent attempts to write to this register fail. ...
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... Read/write 2sC = 1 sets the temperature range to twos complement temperature range. 2sC = 0 changes the temperature range to Offset 64. When this bit is changed, the ADT7467 interprets all relevant temperature register values as defined by this bit. <1> HF/LF Sets the PWM drive frequency to high frequency mode (0) or low frequency mode (1). ...
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... ADT7467 Table 55. Register 0x7D—Configuration Register 4 (Power-On Default = 0x00) 1 Bit Name R/W Description <1:0> Pin9FUNC Read/write These bits set the functionality of Pin TACH4 (default bidirectional THERM SMBALERT GPIO. <3:2> AINL Read/write These two bits define the input threshold for 2-wire fan speed measurements (low frequency mode only ± ...
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... ADT7467 PROGRAMMING BLOCK DIAGRAM SPEED Figure 84. Rev Page ADT7467 FAN CYCLE/RELATIVE DUTY PWM ...
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... Model Temperature Range ADT7467ARQ –40°C to +120°C ADT7467ARQ-REEL –40°C to +120°C ADT7467ARQ-REEL7 –40°C to +120°C ADT7467ARQZ 1 –40°C to +120°C 1 ADT7467ARQZ-REEL –40°C to +120°C 1 ADT7467ARQZ-REEL7 –40°C to +120°C EVAL-ADT7467EB Pb-free part. 0.193 BSC 16 9 0.154 BSC 0 ...
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... NOTES Rev Page ADT7467 ...
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... ADT7467 NOTES © 2005 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D04498–0–7/05(A) Rev Page ...