L9908 datasheet(103/152 Pages) STMICROELECTRONICS

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Figure 78. Temperature monitor ADC characteristics

The temperature measurement data are stored in a dedicated register and can be retrieved by SPI readout of

TEMP_READ in the register GEN_TEMP_STATUS.

The temperature can be retrieved by the following formula:

Tj C∘ = 1.37C∘×DTEMP_READ −77.4C∘

(25)

Where: DTEMP_READ is the digital word stored in TEMP_READ.

The digitized temperature information is compared by two hysteresis comparators with selectable threshold based

on the following scheme:

If DTEMP ≥ DTEMP_WR_TH occurs for an interval longer than T_otm_wr_flt filtering time, the OTM_WR flag is

set. The error flag remains set until the failure condition is removed.

If DTEMP ≥ DTEMP_SD_TH (= 185deg.) occurs for an interval longer than T_otm_sd_flt filtering time, the

OTM_SD flag is set. The error flag remains set until the failure condition is removed and the flag is cleared by the

SPI command.

The thermal Warning threshold can be configured by the following SPI bit sets:

Table 100. Thermal warning configuration bits

TWN_CFG1

TWN_CFG0

Description

130 deg.

L9908

Functional description

DS13546 - Rev 5

page 103/152

L9908 数据表(PDF) 103 Page - STMicroelectronics