Rainbow Electronics LM99 - Manual (Page 17)

2.0 LM99 Registers
(Continued)
2.8 REMOTE TEMPERATURE OFFSET REGISTERS (RTOHB and RTOLB)
(Read / Write Address 11h):
BIT D7 D6 D5 D4 D3 D2 D1 D0
Value SIGN 64 32 16 8 4 2 1
For RTOHB: Remote Temperature Offset High Byte. Power-on default is LHIGH = RHIGH = 0˚C. 1 LSB = 1˚C. Two’s complement
format.
(Read / Write Address 12h):
BIT D7 D6 D5 D4 D3 D2 D1 D0
Value 0.5 0.25 0.125 0 0 0 0 0
For RTOLB: Remote Temperature Offset High Byte. Power-on default is 0˚C. 1 LSB = 0.125˚C. Two’s complement format.
The offset value written to these registers will automatically be added to or subtracted from the remote temperature measurement
that will be reported in the Remote Temperature registers.
2.9 LOCAL and REMOTE T_CRIT REGISTERS (RCS and LCS)
(Read / Write Address 20h, 19h):
BIT D7 D6 D5 D4 D3 D2 D1 D0
Value SIGN 64 32 16 8 4 2 1
D7–D0: T_CRIT setpoint temperature data. Local power-on default is T_CRIT = 85˚C. Remote power-on default is T_CRIT =
110˚C (+126˚C actual remote diode temperature). 1 LSB = 1˚C, two’s complement format.
2.10 T_CRIT HYSTERESIS REGISTER (TH)
(Read and Write Address 21h):
BIT D7 D6 D5 D4 D3 D2 D1 D0
Value 16 8 4 2 1
D7–D0: T_CRIT Hysteresis temperature. Power-on default is TH = 10˚C. 1 LSB = 1˚C, maximum value = 31.
2.11 FILTER and ALERT CONFIGURE REGISTER
(Read and Write Address BFh):
BIT D7 D6 D5 D4 D3 D2 D1 D0
Value 0 0 0 0 0 Filter Level
ALERT
Configure
D7-D3: is not defined defaults to "0".
D2-D1: input filter setting as defined the table below:
D2 D1 Filter Level
0 0 No Filter
0 1 Level 1
1 0 Level 1
1 1 Level 2
Level 2 sets maximum filtering.
D0: when set to "1" comparator mode is enabled.
2.12 MANUFACTURERS ID REGISTER
(Read Address FEh) Default value 01h.
2.13 DIE REVISION CODE REGISTER
(Read Address FFh) The LM99 version has a default value 31h or 49 decimal. The LM99-1 version has a default value of 34h or
52 decimal. This register will increment by 1 every time there is a revision to the die by National Semiconductor.
LM99
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