AMC6821-Q1 Datasheet, PDF (34/54 Pages) Texas Instruments – INTELLIGENT TEMPERATURE MONITOR AND PWM FAN CONTROLLER

AMC6821-Q1
SBAS475 – JUNE 2009 ...................................................................................................................................................................................................... www.ti.com
Table 14. Memory Map (continued)
ADDR
NAME
R/W
TEMPERATURE MONITORING (continued)
0x1C
PSV-Temp
R/W
0x1D
Remote-Critical-Temp
R/W
PWM CONTROLLER
0x20
FAN-Characteristics
R/W
0x21
DCY-Low-Temp
R/W
0x22
DCY (Duty Cycle)
R/W
0x23
DCY-RAMP
R/W
0x24 Local Temp-Fan Control⁽¹⁾ R/W
0x25 Remote Temp-Fan Control R/W
TACH (RPM) MEASUREMENT
0x08
TACH-DATA-LByte
R
0x09
TACH-DATA-HByte
R
0x10
TACH-Low-Limit-LByte
R/W
0x11
TACH-Low-Limit-HByte
R/W
0x12
TACH-High-Limit-LByte
R/W
0x13
TACH-High-Limit-HByte
R/W
0x1E
TACH-SETTING-LByte
R/W
0x1F
TACH-SETTING-HByte
R/W
0x3A
Reserved
R
0x3B
Reserved
R
DEFAULT
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
0x00
0x69
0
0
PSV8
PSV7
PSV6
PSV5
PSV4
PSV3
Passive Cooling Temperature threshold. 3 LSBs and two MSBs are '0'. For details, refer to the passive cooling
temperature limit in the Temperature Out-of-Range Detection section. Default = 0°C.
RT-C10
RT-C9
RT-C8
RT-C7
RT-C6
RT-C5
RT-C4
RT-C3
The 8 MSBs of Remote Critical temperature shutdown threshold. 3 LSBs are '0'. When the Remote-Temp is equal to or
above this limit, an RCRT interrupt occurs and OVR goes low. Default = +105°C.
0x1D
0x55
0x55
0x52
0x41
0x61
FSPD
0
PWM2
PWM1
PWM0
STIME2
STIME1
STIME0
Spin Dis
PWM Frequency Setting
Spin-Up Time Setting
L-DCY7
L-DCY6
L-DCY5
L-DCY4
L-DCY3
L-DCY2
L-DCY1
L-DCY0
The duty cycle of PWM when the temperature is equal to or below Low-Temp in Auto Temp-Fan Control mode.
Default = 0x55, 33.2%.
DCY7 (MSB)
DCY6
DCY5
DCY4
DCY3
DCY2
DCY1
DCY0
Actual Duty cycle of PWM output. The duty cycle changes immediately after new data are written into this register. 8-bit,
0.39%/bit, range 0%-100%. Default = 33%.
In read operation, the returned data are the actual DCY value driving the PWM-Out pin with two exceptions. Refer to the
DCY Register section.
In write operation, the data written are the actual DCY value driving the PWM-Out pin in Software-DCY control mode.
In all other control modes, the data are not used to drive the PWM. Instead, they are stored in a temporary register, and
used to control the PWM immediately after the control mode is changed to software-DCY control.
RAMPE
STEP1
STEP0
RATE2
RATE1
RATE0
THRE1
THRE0
Ramp Enable
DCY Adjustment Step in
Auto Fan Control
DCY Update Rate in Auto Temp-Fan
Control
Adjustment Threshold in
Auto Temp-Fan Control
L-TEMP4
L-TEMP3
L-TEMP2
L-TEMP1
L-TEMP0
L-SLP2
L-SLP1
L-SLP0
Low-Temp in Auto Local Temp-Fan control.
Slope in Auto Local Temp-Fan control.
R-TEMP4
R-TEMP3 R-TEMP2 R-TEMP1 R-TEMP0
R-SLP2
R-SLP1
R-SLP0
Low-Temp in Auto Remote Temp-Fan control.
Slope in Auto Remote Temp-Fan control.
0x00
0x00
0xFF
0xFF
0x00
0x00
0xFF
0xFF
0x00
0x00
TACH-
DATA7
TACH-
DATA6
TACH-
DATA5
TACH-
DATA4
TACH-
DATA3
TACH-
DATA2
TACH-
DATA1
TACH-
DATA0
Low byte of TACH measurement.
TACH-
DATA15
TACH-
DATA14
TACH-
DATA13
TACH-
DATA12
TACH-
DATA11
TACH-
DATA10
TACH-
DATA9
TACH-
DATA8
High byte of TACH measurement.
TACH-Low-
Limit7
TACH-Low- TACH-Low- TACH-Low- TACH-Low- TACH-Low- TACH-Low- TACH-Low-
Limit6
Limit5
Limit4
Limit3
Limit2
Limit1
Limit0
Low byte of TACH count limit corresponding to minimum allowed RPM. Since the TACH circuit counts between TACH
pulses, a slow fan results in a larger measured value. When the measured value is larger than TACH-Low-Limit, the fan
runs below the allowed minimum speed limit.
TACH-Low-
Limit15
TACH-Low- TACH-Low- TACH-Low- TACH-Low- TACH-Low- TACH-Low- TACH-Low-
Limit14
Limit13
Limit12
Limit11
Limit10
Limit9
Limit8
High byte of TACH Limit corresponding to minimum allowed RPM.
TACH-High- TACH-High- TACH-High- TACH-High- TACH-High- TACH-High- TACH-High- TACH-High-
Limit7
Limit6
Limit5
Limit4
Limit3
Limit2
Limit1
Limit0
Low byte of TACH count Limit corresponding to maximum allowed RPM. Since the TACH circuit counts between TACH
pulses, a fast fan results in a small measured value. When the measurement is less than this limit, the fan runs above the
allowed maximum speed limit.
TACH-High- TACH-High- TACH-High- TACH-High- TACH-High- TACH-High- TACH-High- TACH-High-
Limit15
Limit14
Limit13
Limit12
Limit11
Limit10
Limit9
Limit8
High byte of TACH limit corresponding to maximum allowed RPM.
TACH-
SETTING7
TACH-
TACH-
TACH-
TACH-
TACH-
TACH-
TACH-
SETTING6 SETTING5 SETTING4 SETTING3 SETTING2 SETTING1 SETTING0
Low byte of TACH value corresponding to the predetermined target fan speed. TACH-SETTING must be not greater than
the value corresponding to the RPM for 30% duty cycle when the TACH-MODE bit is cleared ('0').
TACH-
TACH-
TACH-
TACH-
TACH-
TACH-
TACH-
TACH-
SETTING15 SETTING14 SETTING13 SETTING12 SETTING11 SETTING10 SETTING9 SETTING8
High byte of TACH value corresponding to the predetermined fan speed. TACH-SETTING must be not greater than the
value corresponding to the RPM for 30% duty cycle when the TACH-MODE bit is cleared ('0').
Always read '0'.
Always read '0'.
(1) Used to calculate the target PWM duty cycle for local temperature in maximum fast-speed calculated control.
34
Submit Documentation Feedback
Product Folder Link(s): AMC6821-Q1
Copyright © 2009, Texas Instruments Incorporated