收藏本站
ADT7490
Disabling Fan Startup Timeout
Although a fan startup makes fan spin-ups much quieter
than fixed-time spin-ups, the option exists to use fixed
spin-up times. Setting Bit 3 (FSPDIS) to 1 in Configuration
Register 7 (Register 0x11) disables the spin-up for two
TACH pulses. Instead, the fan spins up for the fixed time as
selected in Register 0x5C to Register 0x5E.
PWM Logic State
The PWM outputs can be programmed high for 100%
duty cycle (non-inverted) or low for 100% duty cycle
(inverted).
Table 33. PWM1 CONFIGURATION (REG. 0x5C)
Bit Mnemonic Description
Fan Speed Control
The ADT7490 controls fan speed using automatic and
manual modes.
In automatic fan speed control mode, fan speed is
automatically varied with temperature and without CPU
intervention, once initial parameters are set up. The
advantage is that, if the system hangs, the user is guaranteed
that the system is protected from overheating.
In manual fan speed control mode, the ADT7490 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] of Register 0x5C to Register 0x5E (PWM
Configuration) control the behavior of each PWM output.
[4]
INV
0 = Logic High for 100% PWM Duty
Cycle (Non-inverted)
Table 37. PWM CONFIGURATION REGISTERS
(REG. 0x5C TO REG. 0x5E)
1 = Logic Low for 100% PWM Duty
Cycle (Inverted)
Bit
[7:5]
Mnemonic
BHVR
Description
111 = Manual Mode
Table 34. PWM2 CONFIGURATION (REG. 0x5D)
Once under manual control, each PWM output can be
Bit
[4]
Mnemonic
INV
Description
0 = Logic High for 100% PWM Duty
Cycle
1 = Logic Low for 100% PWM Duty
Cycle
manually updated by writing to Register 0x30 to
Register 0x32 (PWMx current duty cycle registers).
Programming the PWM Current Duty Cycle Registers
The PWM current duty cycle registers are 8-bit registers
Table 35. PWM3 CONFIGURATION (REG. 0x5E)
that allow the PWM duty cycle for each output to be set
anywhere from 0% to 100% in steps of 0.39%. The value to
Bit
[4]
Mnemonic
INV
Description
0 = Logic High for 100% PWM Duty
Cycle (Non-inverted)
be programmed into the PWM MIN register is given by
Value (decimal) = PWM MIN /0.39%
1 = Logic Low for 100% PWM Duty
Cycle (Inverted)
Low Frequency Mode PWM Drive Frequency
The PWM drive frequency can be adjusted for the
application. Register 0x5F to Register 0x61 configure the
PWM frequency for PWM1 to PWM3, respectively.
Table 36. PWM1, PWM2, PWM3 FREQUENCY
REGISTERS (REG. 0x5F TO 0x61)
Example 1
For a PWM duty cycle of 50%,
Value (decimal) = 50%/0.39% = 128 (decimal)
Value = 128 (decimal) or 0x80 (hexadecimal)
Example 2
For a PWM duty cycle of 33%,
Value (decimal) = 33%/0.39% = 85 (decimal)
Value = 85 (decimal) or 0x54 (hexadecimal)
Bit
[2:0]
Mnemonic
FREQ
Description
000 = 11.0 Hz
001 = 14.7 Hz
010 = 22.1 Hz
011 = 29.4 Hz
100 = 35.3 Hz (Default)
101 = 44.1 Hz
110 = 58.8 Hz
111 = 88.2 Hz
Table 38. PW M DUTY CYCLE REGISTERS
Register Description Default
0x30 PWM1 Current Duty Cycle 0xFF (100%)
0x31 PWM2 Current Duty Cycle 0xFF (100%)
0x32 PWM3 Current Duty Cycle 0xFF (100%)
By reading the PWMx current duty cycle registers, the
High Frequency Mode PWM Drive
Setting Bit 3 of Register 0x5F, Register 0x60, and
Register 0x61 enables high frequency mode for Fan 1,
Fan 2, and Fan 3, respectively.
In high frequency mode, the PWM drive frequency is
always 22.5 kHz. When high frequency mode is enabled, the
dc bits are automatically asserted internally and do not need
to be changed.
user can keep track of the current duty cycle on each PWM
output, even when the fans are running in automatic fan
speed control mode or acoustic enhancement mode.
Programming T RANGE
T RANGE defines the distance between T MIN and 100%
PWM. For the ADT7467, ADT7468, and ADT7473,
T RANGE is effectively a slope. For the ADT7475, ADT7476,
and ADT7490, T RANGE is no longer a slope but defines the
http://onsemi.com
32
发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

*型号 *数量 厂商 批号 封装
添加更多采购

我的联系方式

*
*
*
相关PDF资料
ADZS-21262-1-EZEXT BOARD DAUGHTER FOR ADSP-21262
ADZS-BF-EZEXT-1 BOARD DAUGHTER ADSP-BF533/561KIT
ADZS-BFAV-EZEXT BOARD DAUGHT ADSP-BF533,37,61KIT
ADZS-BFSHUSB-EZEXT BOARD DAUGHTER EZ EXTENDER
ADZS-BRKOUT-EX3 ADZS-BRKOUT-EX3
ADZS-SHAUDIO-EZEXT SHARC AUDIO EZ-EXTENDER
ADZS-WVGALCD-EX3 BOARD EXTENDER WVGA/LCD EI3
AGA-3 FUSE 3A 125VAC 1AG FAST
相关代理商/技术参数
ADT75 制造商:AD 制造商全称:Analog Devices 功能描述:+-1∑C Accurate, 12-Bit Digital Temperature Sensor
ADT7516 制造商:AD 制造商全称:Analog Devices 功能描述:SPI/I2C Compatible, Temperature Sensor, Four Channel ADC and Quad Voltage Output DAC
ADT7516_06 制造商:AD 制造商全称:Analog Devices 功能描述:SPI-/I2C-Compatible, Temperature Sensor,4-Channel ADC and Quad Voltage Output
ADT7516ARQ 功能描述:IC TEMP SNSR QUAD DAC 16-QSOP RoHS:否 类别:集成电路 (IC) >> PMIC - 热管理 系列:- 标准包装:2,500 系列:SilentSense™ 功能:温度监控系统（传感器） 传感器类型:内部和外部 感应温度:-55°C ~ 125°C，外部传感器 精确度:±2°C 本地（最大），±3°C 远程（最大） 拓扑:ADC（三角积分型），比较器，寄存器库 输出类型:I²C?/SMBus? 输出警报:是 输出风扇:是 电源电压:2.7 V ~ 5.5 V 工作温度:-55°C ~ 125°C 安装类型:表面贴装 封装/外壳:8-TSSOP，8-MSOP（0.118"，3.00mm 宽） 供应商设备封装:8-MSOP 包装:带卷 (TR) 其它名称:MIC284-2BMMTRMIC284-2BMMTR-ND
ADT7516ARQ-REEL 制造商:Analog Devices 功能描述:Temp Sensor Digital Serial (4-Wire, SPI, I2C) 16-Pin QSOP T/R 制造商:Analog Devices 功能描述:TEMP SENSOR DGTL SERL (4-WIRE, SPI) 16QSOP - Tape and Reel
ADT7516ARQ-REEL7 制造商:Analog Devices 功能描述:Temp Sensor Digital Serial (4-Wire, SPI, I2C) 16-Pin QSOP T/R 制造商:Analog Devices 功能描述:TEMP SENSOR DGTL SERL (4-WIRE, SPI) 16QSOP - Tape and Reel
ADT7516ARQZ 功能描述:IC TEMP SNSR QUAD DAC 16-QSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 热管理 系列:- 标准包装:3,000 系列:- 功能:温度开关 传感器类型:内部 感应温度:85°C 分界点 精确度:±6°C（最小值） 拓扑:ADC（三角积分型），比较器，寄存器库 输出类型:开路漏极 输出警报:是 输出风扇:是 电源电压:2.7 V ~ 5.5 V 工作温度:-55°C ~ 125°C 安装类型:表面贴装 封装/外壳:SC-74A，SOT-753 供应商设备封装:SOT-23-5 包装:带卷 (TR) 其它名称:ADT6501SRJZP085RL7-ND
ADT7516ARQZ-REEL 制造商:Analog Devices 功能描述:Temp Sensor Digital Serial (4-Wire, SPI, I2C) 16-Pin QSOP T/R