Datasheet

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SLLS672A − OCTOBER 2005 − REVISED JANUARY 2006
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7
CONVERTER RESOLUTION (R1/R0)
The Converter Resolution bits control the resolution of the
internal analog-to-digital (A/D) converter. This control
allows the user to maximize efficiency by programming for
higher resolution or faster conversion time. Table 8
identifies the resolution bits and the relationship between
resolution and conversion time.
R1 R0 RESOLUTION
CONVERSION TIME
(typical)
0 0 9 Bits (0.5°C) 27.5ms
0 1 10 Bits (0.25°C) 55ms
1 0 11 Bits (0.125°C) 110ms
1 1 12 Bits (0.0625°C) 220ms
Table 8. Resolution of the TMP106
ONE-SHOT (OS)
The TMP106 features a One-Shot Temperature
Measurement Mode. When the device is in Shutdown
Mode, writing a ‘1’ to the OS bit starts a single temperature
conversion. The device will return to the shutdown state at
the completion of the single conversion. This option is
useful to reduce power consumption in the TMP106 when
continuous temperature monitoring is not required. When
the Configuration Register is read, the OS always reads
zero.
HIGH AND LOW LIMIT REGISTERS
In Comparator Mode (TM = 0), the ALERT pin of the
TMP106 becomes active when the temperature equals or
exceeds the value in T
HIGH
and generates a consecutive
number of faults according to fault bits F1 and F0. The
ALERT pin remains active until the temperature falls below
the indicated T
LOW
value for the same number of faults.
In Interrupt Mode (TM = 1), the ALERT pin becomes active
when the temperature equals or exceeds T
HIGH
for a
consecutive number of fault conditions. The ALERT pin
remains active until a read operation of any register
occurs, or until the device successfully responds to the
SMBus Alert Response address. The ALERT pin clears if
the device is placed in Shutdown Mode. Once the ALERT
pin is cleared, it will only become active again by the
temperature falling below T
LOW
. When the temperature
falls below T
LOW
, the ALERT pin becomes active and
remains active until cleared by a read operation of any
register or a successful response to the SMBus Alert
Response address. When the ALERT pin clears, the
above cycle will repeat, with the ALERT pin becoming
active when the temperature equals or exceeds T
HIGH
.
The ALERT pin can also be cleared by resetting the device
with the General Call Reset command. This reset also
clears the state of the internal registers in the device,
returning the device to Comparator Mode (TM = 0).
Both operational modes are represented in Figure 3.
Table 9 and Table 10 describe the format for the T
HIGH
and
T
LOW
Registers. Note that the most significant byte is sent
first, followed by the least significant byte. Power-up reset
values for T
HIGH
and T
LOW
are:
T
HIGH
= 80°C and T
LOW
= 75°C
The format of the data for T
HIGH
and T
LOW
is the same as
for the Temperature Register.
BYTE D7 D6 D5 D4 D3 D2 D1 D0
1 H11 H10 H9 H8 H7 H6 H5 H4
BYTE D7 D6 D5 D4 D3 D2 D1 D0
2 H3 H2 H1 H0 0 0 0 0
Table 9. Bytes 1 and 2 of T
HIGH
Register
BYTE D7 D6 D5 D4 D3 D2 D1 D0
1 L11 L10 L9 L8 L7 L6 L5 L4
BYTE D7 D6 D5 D4 D3 D2 D1 D0
2 L3 L2 L1 L0 0 0 0 0
Table 10. Bytes 1 and 2 of T
LOW
Register
All 12 bits for the Temperature, T
HIGH
, and T
LOW
Registers
are used in the comparisons for the ALERT function for all
converter resolutions. The three LSBs in T
HIGH
and T
LOW
can affect the ALERT output even if the converter is
configured for 9-bit resolution.
SERIAL INTERFACE
The TMP106 operates only as a slave device on the
Two-Wire bus and SMBus. Connections to the bus are
made via the open-drain I/O lines SDA and SCL. The SDA
and SCL pins feature integrated spike suppression filters
and Schmitt triggers to minimize the effects of input spikes
and bus noise. The TMP106 supports the transmission
protocol for fast (1kHz to 400kHz) and high-speed (1kHz
to 3.4MHz) modes. All data bytes are transmitted MSB
first.