EMC1413 datasheet(22/52 Pages) SMSC

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Multiple Channel 1°C Temperature Sensors with Beta Compensation

Datasheet

Revision 1.41 (02-23-12)

SMSC EMC1413 / EMC1414

DATASHEET

typically done using programmable offset registers. Since an ideality factor mismatch introduces an

error that is a function of temperature, this correction is only accurate within a small range of

temperatures. To provide maximum flexibility to the user, the EMC1413 / EMC1414 provides a 6-bit

errors across all temperatures.

APPLICATION NOTE: When monitoring a substrate transistor or CPU diode and beta compensation is enabled, the

Ideality Factor should not be adjusted. Beta Compensation automatically corrects for most

ideality errors.

6.5

Diode Faults

The EMC1413 / EMC1414 detects an open on the DP and DN pins, and a short across the DP and

DN pins. For each temperature measurement made, the device checks for a diode fault on the external

diode channel(s). When a diode fault is detected, the ALERT pin asserts (unless masked, see

Section 6.6) and the temperature data reads 00h in the MSB and LSB registers (note: the low limit will

not be checked). A diode fault is defined as one of the following: an open between DP and DN, a short

from VDD to DP, or a short from VDD to DN.

If a short occurs across DP and DN or a short occurs from DP to GND, the low limit status bit is set

and the ALERT pin asserts (unless masked). This condition is indistinguishable from a temperature

measurement of 0.000°C (-64°C in extended range) resulting in temperature data of 00h in the MSB

and LSB registers.

If a short from DN to GND occurs (with a diode connected), temperature measurements will continue

as normal with no alerts.

6.6

Consecutive Alerts

The EMC1413 / EMC1414 contain multiple consecutive alert counters. One set of counters applies to

the ALERT pin and the second set of counters applies to the THERM pin. Each temperature

measurement channel has a separate consecutive alert counter for each of the ALERT and THERM

pins. All counters are user programmable and determine the number of consecutive measurements

that a temperature channel(s) must be out-of-limit or reporting a diode fault before the corresponding

pin is asserted.

See Section 7.12, "Consecutive ALERT Register" for more details on the consecutive alert function.

6.7

Digital Filter

To reduce the effect of noise and temperature spikes on the reported temperature, the External Diode

1 channel uses a programmable digital filter. This filter can be configured as Level 1, Level 2, or

Disabled (default) (see Section 7.18). The typical filter performance is shown in Figure 6.3 and

Figure 6.4.

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