EVAL-ADT7470EB Analog Devices Inc, EVAL-ADT7470EB Datasheet
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EVAL-ADT7470EB
Specifications of EVAL-ADT7470EB
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EVAL-ADT7470EB Summary of contents
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FEATURES Monitors remote temperature sensors Monitors and controls speed fans independently PWM outputs drive each fan under software control FULL_SPEED input allows fans to be blasted to maximum speed by external hardware SMBALERT ...
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ADT7470 TABLE OF CONTENTS Features .............................................................................................. 1 Applications ....................................................................................... 1 General Description ......................................................................... 1 Functional Block Diagram .............................................................. 1 Revision History ............................................................................... 2 Specifications ..................................................................................... 3 Serial Bus Timing Specifications ................................................ 4 Absolute Maximum Ratings ............................................................ 5 Thermal Characteristics .............................................................. ...
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SPECIFICATIONS − +125 3 5.5 V, unless otherwise noted Table Parameter 1 POWER SUPPLY Supply Voltage Supply Current Standby ...
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ADT7470 SERIAL BUS TIMING SPECIFICATIONS Table Parameter SERIAL BUS TIMING Clock Frequency, f SCLK Glitch Immunity Bus Free Time, t BUF Start Setup Time, t SU;STA Start Hold Time, t HD;STA SCL ...
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ABSOLUTE MAXIMUM RATINGS Table 3. Parameter Positive Supply Voltage ( Voltage on Any TACH or PWM Pin Voltage on Any Input or Output Pin Maximum Junction Temperature (T max) J Storage Temperature Range Lead Temperature, Soldering Vapor Phase, ...
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ADT7470 PIN CONFIGURATION AND FUNCTION DESCRIPTIONS Table 4. Pin Function Descriptions Pin No. Mnemonic Description 1 SCL Digital Input (Open Drain). SMBus serial clock input. Requires SMBus pull-up, typically 2k2Ω. 2 GND Ground Pin Power Supply Pin. CC ...
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FUNCTIONAL DESCRIPTION GENERAL DESCRIPTION The ADT7470 is a multichannel, pulse-width modulation (PWM) fan controller and monitor for any system requiring monitoring and cooling. The device communicates with the system via a serial system management bus. The device has a single ...
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ADT7470 GENERAL-PURPOSE I/O PINS (OPEN DRAIN) The ADT7470 has four pins that can be configured as either general-purpose logic pins or as PWM outputs. Each GPIO pin has a corresponding enable, direction, polarity and status bit. Pin GPIO1 GPIO2 GPIO3 ...
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SMBUS/I C SERIAL INTERFACE Control of the ADT7470 is carried out using the serial system management bus (SMBus). This interface is fully compatible with SMBus 2.0 electrical specifications and meets 400 pF bus capacitance requirements. The device also supports ...
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ADT7470 during the low period before the 10th clock pulse, then high during the 10th clock pulse to assert a stop condition. Any number of bytes of data can be transferred over the serial bus in one operation. However, it ...
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The first data byte is the address of the internal data register to be written to, which is stored in the address pointer register. The second data byte is the data to be written to the internal data register. How ...
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ADT7470 READ OPERATIONS The ADT7470 uses the following SMBus read protocols. Receive Byte This is useful when repeatedly reading a single register. The register address must be set up previously. In this operation, the master device receives a single byte ...
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TEMPERATURE MEASUREMENT USING TMP05/TMP06 MEASURING TEMPERATURE The ADT7470 can be connected with daisy-chained TMP05/TMP06 devices for temperature measurement. Each TMP05/TMP06 performs an ambient temperature measure- ment, and outputs a PWM signal. The ADT7470 decodes the PWM into ...
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ADT7470 TEMPERATURE READBACK BY THE HOST The user cannot read the ADT7470 temperature register values if the ADT7470 is in the process of a temperature measurement. The user must wait until the data from all the TMP05s and TMP06s in ...
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TEMPERATURE MEASUREMENT LIMITS High and low temperature limits can be individually set for each of the TPM05/06s that the ADT7470 is monitoring. The temperature limit registers are at address 0x44 to 0x57. The power-on default value for all TMP05/06 lower ...
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ADT7470 LIMIT AND STATUS REGISTERS LIMIT VALUES Associated with each measurement channel on the ADT7470 are high and low limits. These can form the basis of system status monitoring; a status bit can be set for any out-of-limit condition and ...
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STATUS REGISTERS The results of limit comparisons are stored in Status Register 1 and Status Register 2. The status register bit for each channel reflects the status of the last measurement and limit comparison on that channel measurement ...
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ADT7470 SMBALERT INTERRUPT The ADT7470 can be polled for status SMBALERT interrupt can be generated for out-of-limit conditions. Note how the SMBALERT output and status bits behave when writing interrupt handler software. Figure 15 shows how the SMBALERT ...
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Masking Interrupt Sources Interrupt Mask Register 1 and Interrupt Mask Register 2 are located at Address 0x72 and Address 0x73. These allow indi- vidual interrupt sources to be masked out to prevent unwanted SMBALERT interrupts. Masking an interrupt source prevents ...
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ADT7470 FAN DRIVE USING PWM CONTROL The ADT7470 uses pulse-width modulation (PWM) to control fan speed. This relies on varying the duty cycle (or on/off ratio square wave applied to the fan to vary the fan speed. Two ...
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Figure 19 shows a fan drive circuit using an NPN transistor such as a general-purpose MMBT2222. While these devices are inexpensive, they tend to have much lower current handling capabilities and higher on resistance than MOSFETs. When choosing a transistor, ...
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ADT7470 FAN SPEED MEASUREMENT TACH INPUTS Pin 6, Pin 7, Pin 4, and Pin 9 are open-drain tach inputs intended for fan speed measurement. Signal conditioning in the ADT7470 accommodates the slow rise and fall times typical of fan tachometer ...
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FAN SPEED MEASUREMENT The fan counter does not count the fan tach output pulses directly, because the fan speed may be less than 1000 RPM, and it would take several seconds to accumulate a reasonably large and accurate count. Instead, ...
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ADT7470 Calculating Fan Speed Assuming that the measured number of tach pulses per rotation corresponds to the number of pulses counted as set in register 0x43, fan speed is calculated by Fan Speed (RPM) = (90,000 × 60)/Fan Tach Reading ...
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MANUAL FAN SPEED CONTROL Manual fan speed control on the ADT7470 allows the user to control the PWM duty cycle for each fan via the registers. The ADt7470 powers-up in manual fan control mode, with all PWM duty cycles set ...
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ADT7470 AUTOMATIC FAN SPEED CONTROL In automatic fan speed control mode, fan speed automatically varies with temperature and without CPU intervention, once initial parameters are set up. The advantage is that when a system hangs, the user is guaranteed that ...
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REGISTER MAP Table 23. ADT7470 Register Map Address R/W Description 0x20 R Temperature 1 Reading 0x21 R Temperature 2 Reading 0x22 R Temperature 3 Reading 0x23 R Temperature 4 Reading 0x24 R Temperature 5 Reading 0x25 R Temperature 6 Reading ...
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ADT7470 Address R/W Description 0x54 R/W Temperature 9 Low Limit 0x55 R/W Temperature 9 High Limit 0x56 R/W Temperature 10 Low Limit 0x57 R/W Temperature 10 High Limit 0x58 R/W Tach 1 Min Low Byte 0x59 R/W Tach 1 Min ...
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DETAILED REGISTER DESCRIPTIONS Table 24. Register 0x20 to Register 0x29. Temperature Reading Registers (Power-On Default = 0x00). Register Address Read/Write Description 0x20 Read-only 8-bit Temperature 1 reading (from TMP05 sensor). 0x21 Read-only 8-bit Temperature 2 reading (from TMP05 sensor). 0x22 ...
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ADT7470 Table 27. Register 0x38 to Register 0x3B. PWM Max Duty Cycle Registers (Power-On Default = 0xFF). Register Address Read/Write 0x38 Read/Write 0x39 Read/Write 0x3A Read/Write 0x3B Read/Write Table 28. Register 0x3D. Device ID Register (Power-On Default = 0x70). Register ...
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Table 32. Register 0x41. Interrupt Status Register 1 (Power-On Default = 0x00). Bit Name Read/Write [0] R1T Read-only [1] R2T Read-only [2] R3T Read-only [3] R4T Read-only [4] R5T Read-only [5] R6T Read-only [6] R7T Read-only [7] OOL Read-only Table ...
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ADT7470 Table 34. Register 0x43. Fan Pulses per Revolution Register (Power-On Default = 0x55). Bit Name Read/Write Description [1:0] Fan 1 Read/Write Sets the number of pulses to be counted when measuring Fan 1 speed. Can be used to determine ...
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Table 36. Register 0x58 to Register 0x67. Fan Tachometer Limit Registers. Register Address Read/Write 0x58 Read/Write 0x59 Read/Write 0x5A Read/Write 0x5B Read/Write 0x5C Read/Write 0x5D Read/Write 0x5E Read/Write 0x5F Read/Write 0x60 Read/Write 0x61 Read/Write 0x62 Read/Write 0x63 Read/Write 0x64 Read/Write ...
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ADT7470 Table 38. Register 0x69. PWM3/PWM4 Configuration Register (Power-On Default = 0x00). Bit Name Read/Write [0] N/A [1] N/A [2] N/A [3] N/A [4] INV4 Read/Write [5] INV3 Read/Write [6] BHVR4 Read/Write [7] BHVR3 Read/Write Table 39. Register 0x6A to ...
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Table 42. Register 0x72. Interrupt Mask Register 1 (Power-On Default = 0x00). Bit Name Read/Write [7] Not in use Read/Write [6] R7T Read/Write [5] R6T Read/Write [4] R5T Read/Write [3] R4T Read/Write [2] R3T Read/Write [1] R2T Read/Write [0] R1T ...
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ADT7470 Table 44. Register 0x74. Configuration Register 2 (Power-On Default = 0x00). Bit Name Read/Write [7] SHDN Read/Write [6:4] FREQ Read/Write [3] T4_dis Read/Write [2] T3_dis Read/Write [1] T2_dis Read/Write [0] T1_dis Read/Write Table 45. Register 0x78. Max TMP05 Temperature ...
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Table 47. Register 0x7D. TMP05 Zone Select 2 (Power-On Default = 0x00). Bit Name Read/Write [7:4] zone_fan3[3:0] Read/Write [3:0] zone_fan4[3:0] Read/Write Table 48. Register 0x7F. GPIO Enable (Power-On Default = 0x00). Bit Name Read/Write [7:6] Reserved Read/Write [5:4] Reserved Read/Write ...
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ADT7470 Table 49. Register 0x80. GPIO CONFIG (Power-On Default = 0x00). Bit Name Read/Write Description [7] GPIO1_d Read/Write This bit sets the direction of GPIO 1 when the PWM1 pin is configured as GPIO. 1= output input. Data ...
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... REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN. ORDERING GUIDE Model Temperature Range 1 ADT7470ARQZ −40°C to +125°C 1 ADT7470ARQZ-REEL −40°C to +125°C 1 ADT7470ARQZ-REEL7 −40°C to +125°C 1 EVAL-ADT7470EBZ RoHS Compliant Part. 0.197 (5.00) 0.193 (4.90) 0.189 (4.80 0.158 (4.01) 0.154 (3.91) 0.244 (6.20) 0.150 (3.81) 1 0.236 (5.99 ...
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ADT7470 NOTES Purchase of licensed components of Analog Devices or one of its sublicensed Associated Companies conveys a license for the purchaser under the Philips I Rights to use these components system, ...