L9662 datasheet(29/80 Pages) STMICROELECTRONICS

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L9662

Functional description

using a 3.3 to 5.0 volt supply. When chip select is asserted, both the SPI master and this

device shall latch input data on the rising edge of SCLK/SCLK_S. The ASIC shifts data out

on the falling edge of SCLK/SCLK_S.

Serial data output (MISO, MISO_S)

MISO/MISO_S output pins shall be in a tri-state condition when chip select is negated.

When chip select is asserted, the MSB is the first bit of the word/byte transmitted on

MISO/MISO_S and the LSB is the last bit of the word/byte transmitted. This pin supplies a

rail to rail output, so if interfaced to a microprocessor that is using a lower VDD supply, the

appropriate microprocessor input pin shall not sink more than IOH(min) and shall not clamp

the MISO/MISO_S output voltage to less than VOH(min) while MISO/MISO_S pin is in a

logic “1” state.

Serial data input (MOSI, MOSI_S)

MOSI/MOSI_S inputs take data from the master processor while chip select is asserted.

The MSB shall be the first bit of each word/byte received on MOSI/MOSI_S and the LSB

shall be the last bit of each word/byte received.

This pin has TTL level compatible input voltages allowing proper operation with

microprocessors using a 3.3 to 5.0 volt supply.

3.4

Squib drivers

3.4.1

Firing

The on-chip deployment drivers are designed to deliver 1.2 A (min) for 2 ms (min) and

1.75 A (min) for 1 ms (min) with VRESx voltages between 7 V and 37 V. In addition the

device can provide 1.5 A minimum for 2 ms for VRESx voltages between 7 V and 25 V. The

firing condition is selectable via the SPI. At the end of a deployment, a deploy success flag

is asserted and can be read using the appropriate SPI command. Each VRESx and GNDx

connection is used to accommodate 8 loops that can be deployed simultaneously.

Upon receiving a valid deployment condition, the respective SQHx and SQLx drivers are

turned on. The only other activation of the SQHx and SQLx drivers is momentarily during a

MOS diagnostic. Otherwise, SQHx and SQLx are inactive under any normal, fault, or

transient conditions. Upon a successful deployment of the respective SQHx and SQLx

drivers, a deploy command success flag is asserted via SPI. Refer to Figure 8 for the valid

conditions and the deploy success flag timing.

L9662 Datasheet(PDF) 29 Page - STMicroelectronics