L9300 datasheet(46/178 Pages) STMICROELECTRONICS

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9.3.3

Internal supply error handling

Table 22. Internal supply error handling

Type of error

Detection

condition

Action

Clear SPI

flag

Restart condition

V33_AN_uv

ON state

All Outputs OFF, SPI registers reset as

described in SPI register map

N.D.

Automatic with retrigger of power-up

sequence after fault disappears

V33_DIG_uv

ON state

All Outputs OFF, SPI registers reset as

described in SPI register map

N.D.

Automatic with retrigger of power-up

sequence after fault disappears

9.4

Reference oscillator

9.4.1

Reference voltage functional description

The device uses an internal 16 MHz oscillator, trimmed for 7% accuracy, as system clock for digital circuits and as

time base for digital timings and filters. Since a loss of the reference frequency would cause a stuck in the logic

core, this oscillator is duplicated and redundancy is used to guarantee the correct functionality.

To reduce emissions of the main logic core and of the switching circuits in general, spread spectrum is operating

on the main oscillator. A Synchronous Digital Modulator generates 64 total steps to the spread spectrum input.

Half of them modulate the oscillator with a frequency higher than 16 MHz, half of them modulate the oscillator with

a frequency lower than 16 MHz. The frequency deviation is about: ±32 (steps) x 0.1% (spread spectrum

resolution) = ±3%.The 64 different levels at 16 MHz average rate result in a modulation frequency of 16 MHz /

128 = 125 KHz. The central 16 MHz frequency is varied by a triangular modulation at 125 kHz with 3% of

modulation index. Spread spectrum is always active and can be disabled setting the proper bit in the SERVICE

ENABLE register.

9.4.2

Reference oscillator electrical characteristics

5.5 V ≤ VBATP ≤ 19 V; -40 °C ≤ Tj ≤ 175 °C, unless otherwise noticed. All voltages refer to GND pin.

Table 23. Reference oscillator electrical characteristics

Symbol

Parameter

Test condition

Min

Typ

Max

Unit

Internal Oscillator

fOSCINT

Internal Oscillator main frequency

-7%

+7%

MHz

fOSCINT_mod_freq

Spread spectrum modulation frequency

Guaranteed by scan

125

kHz

fOSCINT_mod_id_min

Spread spectrum minimum modulation index

-5

-3

fOSCINT_mod_id_max

Spread spectrum miaximum modulation index

9.5

Thermal monitor

9.5.1

Thermal monitor functional description

To guarantee current control accuracy and real time calibration, the temperature of the die is continuously

monitored through a sigma-delta temperature sensor; temperature information is coded in digital domain in an 8-

bit word stored into a dedicated SPI register. If the die overheats above T_SD_int threshold, solenoid driver and

regulators are disabled until die temperature decreases below turn-off threshold. Die temperature can be

calculated with the following formula:

T= SPICODE

255 ×305 −85 ℃

9.5.2

Thermal monitor electrical characteristics

5.5 V ≤ VBATP ≤ 19 V; -40 °C ≤ Tj ≤ 175 °C, unless otherwise noticed. All voltages refer to GND pin.

L9300

Reset

DS12258 - Rev 5

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