LM63EVAL National Semiconductor, LM63EVAL Datasheet - Page 19

• Manufacturer Part Number: LM63EVAL
• Manufacturer: National Semiconductor

Specifications of LM63EVAL

• Lead Free Status / Rohs Status: Supplier Unconfirmed

ADDRESS
03 (09)
2.0 LM63 Registers
03 (09)
Configuration Register
Hex
HEX
CONFIGURATION REGISTER
Read/
Write
R/W
Bits
4:3
7
6
5
2
1
0
Value
POR
00
0
0
0
0
0
0
(Continued)
PWM Disable
T_CRIT Limit
in STANDBY
ALERT/Tach
RDTS Fault
STANDBY
Override
ALERT
Queue
Select
Name
Mask
When this bit is a 0, ALERT interrupts are enabled.
When this bit is set to a 1, ALERT interrupts are masked, and the
ALERT pin is always in a high impedance (open) state.
When this bit is a 0, the LM63 is in operational mode, converting,
comparing, and updating the PWM output continuously.
When this bit is a 1, the LM63 enters a low power standby mode.
In STANDBY, continuous conversions are stopped, but a
conversion/comparison cycle may be initiated by writing any value to
register 0x0F. Operation of the PWM output in STANDBY depends on
the setting of bit 5 in this register.
When this bit is a 0, the LM63’s PWM output continues to output the
current fan control signal while in STANDBY.
When this bit is a 1, the PWM output is disabled (as defined by the
PWM polarity bit) while in STANDBY.
These bits are unused and always set to 0.
When this bit is a 0, the ALERT/Tach pin is an open drain ALERT
output.
When this bit is a 1, the ALERT/Tach pin is a high impedance
Tachometer input.
Note that if this bit is set, the function of the ALERT/Tach pin must be
Tach input, so an external ALERT condition will not occur.
The T_CRIT limit for the remote diode is nominally 85˚C. This value can
be changed once after power-up by first setting this bit to a 1, then
programming a new T_CRIT value into the Remote Diode T_CRIT Limit
(register 0x19). The T_CRIT value can not be changed again except by
cycling power to the LM63.
0: an ALERT will be generated if any Remote Diode conversion result is
above the Remote High Set Point or below the Remote Low
Setpoint.
1: an ALERT will be generated only if three consecutive Remote Diode
conversions are above the Remote High Set Point or below the
Remote Low Setpoint.
19
Description
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