33984 datasheet(29/38 Pages) FREESCALE

29 / 38 page

Analog Integrated Circuit Device Data

Freescale Semiconductor

33984

TYPICAL APPLICATIONS

Figure 11. Typical Applications

The loads must be chosen in order to guarantee the device

normal operating conditions for junction temperatures from -

40 to 150°C. In case of permanent short-circuit conditions,

the duration and number of activation cycles must be limited

with a dedicated MCU fault management, using the fault

reporting through the SPI. When driving DC motor or

Solenoid loads demanding multiple switching, an external

recirculation device must be used to maintain the device in its

Safe Operating Area.

Two application notes are available:

• AN3274, which proposes safe configurations of the

eXtreme Switch devices in case of application faults, and

to protect all circuitry with minimum external components.

• AN2469, which provides guidelines for Printed Circuit

Board (PCB) design and assembly.

Development effort will be required by the end users to

optimize the board design and PCB layout, in order to reach

electromagnetic compatibility standards (emission and

immunity).

OUTPUT CURRENT MONITORING

This section relates to the output current monitoring for

33984, Dual 4.0 m

Ω High Side Switch. This device is a self-

protected silicon switch used to replace electromechanical

relays, fuses, and discrete circuits in power management

applications. The MC33984 features a current recopy which

is proportional to the load current. It can be configured

between 2 ratios via SPI (CSR0 and CSR1).

This section presents the current recopy tolerance of the

device and the improvement of this feature with the

calibration practice.

CURRENT RECOPY TOLERANCE

The Current Sense Ratio Accuracies described page 9

and 10 (CSR0_ACC and CSR1_ACC) take into account:

• part to part deviation due to manufacturing,

• ambient temperature derating (from -40 to 125°C),

• battery voltage range (from 9 to 16 V).

Thanks to statistical data analysis performed on 3

production lots (initial testing only), the effect of each

contributor has been demonstrated.

A/D

MCU

I/O

SCLK

I/O

VDD

FSI

CSNS

RST

IN0

SCLK

WAKE

NC VPWR

33984

100 nF

10 µF

VDD

GND

HS1

HS0

VPWR

2.5µF

10nF

LOAD

RFSI

2.2k

10k

VDD

LOAD

Voltage

Regulator

VDD

VPWR

IN1

I/O

10 k

33984 Datasheet(PDF) 29 Page - Freescale Semiconductor, Inc

33984 Datasheet(HTML) 29 Page - Freescale Semiconductor, Inc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38

Datasheet Download

Link URL