Table 8-4. Conversion Rate (continued)

VALUE

CONVERSIONS PER SECOND

TIME (SECONDS)

09h

32

0.03125

8.1.6 One-Shot Start Register

When the TMP461-EP device is in shutdown mode (SD = 1 in the configuration register), a single conversion

is started by writing any value to the one-shot start register, pointer address 0Fh. This write operation starts

one conversion and comparison cycle on either both the local and remote sensors or on only one or the other

sensor, depending on the LEN and REN values configured in the channel enable register (read address 16h,

write address 16h). The TMP461-EP device returns to shutdown mode when the cycle completes. The value of

the data sent in the write command is irrelevant and is not stored by the TMP461-EP device.

8.1.7 Channel Enable Register

The channel enable register (read address 16h, write address 16h) enables or disables the temperature

conversion of remote and local temperature sensors. LEN (bit 0) of the channel enable register enables/disables

the conversion of local temperature. REN (bit 1) of the channel enable register enables/disables the conversion

of remote temperature. Both LEN and REN are set to 1 (default), which enables the ADC to convert both local

and remote temperatures. If LEN is set to 0, the local temperature conversion is disabled, and similarly, if REN is

set to 0, the remote temperature conversion is disabled.

Both local and remote temperatures are converted by the internal ADC as a default mode. The Channel Enable

register can be configured to achieve power savings by reducing the total ADC conversion time to half for

applications that do not require both remote and local temperature information.

8.1.8 Consecutive ALERT Register

The Consecutive ALERT register (read address 22h, write address 22h) controls the number of out-of-limit

temperature measurements required for ALERT to be asserted. Table 8-5 summarizes the values of the

consecutive ALERT register. The number programmed in the consecutive ALERT applies to both the remote

and local temperature results. When the number of times that the temperature result consecutively exceeds the

high limit register value is equal to the value programmed in the consecutive ALERT register, ALERT is asserted.

Similarly, the consecutive ALERT register setting is also applicable to the low-limit register.

Table 8-5. Consecutive ALERT

REGISTER VALUE

NUMBER OF OUT-OF-LIMIT MEASUREMENTS REQUIRED TO ASSERT ALERT

01h

1 (default)

03h

2

07h

3

0Fh

4

8.1.9 η-Factor Correction Register

The TMP461-EP device allows for a different η-factor value to be used for converting remote channel

measurements to temperature. The remote channel uses sequential current excitation to extract a differential

VBE voltage measurement to determine the temperature of the remote transistor. Equation 1 shows this voltage

and temperature.

=

V

V

BE2

BE1

-

hkT

q

ln

I

2

I

1

(1)

The value η in Equation 1 is a characteristic of the particular transistor used for the remote channel. The

power-on reset value for the TMP461-EP device is η = 1.008. The value in the η-factor correction register can be

used to adjust the effective η-factor according to Equation 2 and Equation 3.

TMP461-EP

SNIS241 – SEPTEMBER 2025

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