LM64EVAL National Semiconductor, LM64EVAL Datasheet - Page 19

• Manufacturer Part Number: LM64EVAL
• Description: BOARD EVALUATION LM64
• Manufacturer: National Semiconductor

Specifications of LM64EVAL

• Sensor Type: Temperature, Fan Controller
• Sensing Range: 0°C ~ 85°C
• Interface: SMBus (2-Wire/I²C)
• Sensitivity: ±1°C
• Voltage - Supply: 3 V ~ 3.6 V
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: LM64
• Lead Free Status / RoHS Status: Not applicable / Not applicable

Address
4D
4C
2.0 LM64 Registers
Fan Control Registers
Hex
HEX
HEX
4D
4C
FAN PWM FREQUENCY REGISTER
PWM VALUE REGISTER
5 = 1.)
Read/
(Write
only if
4A bit
Write
Read
R/W
reg
Bits
7:5
4:0
7:6
5:0
000000
10111
Value
POR
000
00
(Continued)
(Continued)
Frequency
Name
Value
PWM
PWM
These bits are unused and always set to 0
The PWM Frequency = PWM_Clock / 2n, where PWM_Clock = 360
kHz or 1.4 kHz (per the PWM Clock Select bit in Register 4A), and n =
value of the register. Note: n = 0 is mapped to n = 1. See the
Application Note at the end of this datasheet.
These bits are unused and always set to 0
If PWM Program (register 4A, bit 5) = 0 this register is read only and
reflects the LM64’s current PWM value from the Lookup Table.
If PWM Program (register 4A, bit 5) = 1, this register is read/write and
the desired PWM value is written directly to this register, instead of
from the Lookup Table, for direct fan speed control.
This register will read 0 during the Spin-Up cycle.
See Application Notes section at the end of this datasheet for more
information regarding the PWM Value and Duty Cycle in %.
19
Description
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