TYPICAL APPLICATIONS
TYPICAL APPLICATIONS
VPWR
VDD
Voltage
Regulator
VDD
VDD NC VPWR
VDD
VPWR
2.2k
10k
10
MCU
14
VDD
VPWR
HS1
100 nF
10 µF
2.5 µF
10 nF
2
4
WAKE
IN0
10 k
15
16
I/O
I/O
10 k
12
8
IN1
10 k
10 k
33984
SCLK
CS
SCLK
CS
7
10 k
3
I/O
RST
SO
SI
HS0
11
9
SI
SO
I/O
10 k
5
FS
LOAD
LOAD
1
13
CSNS
FSI
A/D
GND
6
1 k
RFSI
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.
• 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).
Two application notes are available:
OUTPUT CURRENT MONITORING
This section relates to the output current monitoring for
33984, Dual 4.0 mΩ 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).
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.
This section presents the current recopy tolerance of the
device and the improvement of this feature with the
calibration practice.
33984
Analog Integrated Circuit Device Data
Freescale Semiconductor
29
FREESCALE [ Freescale ]
