Freescale Semiconductor
Technical Data
Document Number: MC33984
Rev. 12.0, 4/2010
Dual Intelligent High-current
Self-protected Silicon High Side
Switch (4.0 mΩ)
The 33984 is a dual self-protected 4.0 mΩ silicon switch used to
replace electromechanical relays, fuses, and discrete devices in
power management applications. The 33984 is designed for harsh
environments, and it includes self-recovery features. The device is
suitable for loads with high inrush current, as well as motors and all
types of resistive and inductive loads.
Programming, control, and diagnostics are implemented via the
Serial Peripheral Interface (SPI). A dedicated parallel input is available
for alternate and pulse-width modulation (PWM) control of each
output. SPI-programmable fault trip thresholds allow the device to be
adjusted for optimal performance in the application.
The 33984 is packaged in a power-enhanced 12 x 12 nonleaded
PQFN package with exposed tabs.
Features
Dual 4.0 mΩ max high side switch with parallel input or SPI control
6.0 to 27 V operating voltage with standby currents < 5.0
μA
Output current monitoring with two SPI-selectable current ratios
SPI control of over-current limit, over-current fault blanking time,
output-OFF open load detection, output ON/OFF control, watchdog
timeout, slew rates, and fault status reporting
• SPI status reporting of over-current, open and shorted loads, over-
temperature, under-voltage and over-voltage shutdown, fail-safe
pin status, and program status
• Enhanced -16 V reverse polarity V
PWR
protection
•
•
•
•
33984B/C
HIGH SIDE SWITCH
BOTTOM VIEW
PNA SUFFIX
98ARL10521D
16-PIN PQFN
ORDERING INFORMATION
Device
MC33984BPNA/R2
- 40°C to 125°C
MC33984CPNA/R2
16 PQFN
Temperature
Range (T
A
)
Package
V
DD
V
DD
V
DD
V
PWR
33984
VDD
I/O
I/O
SO
SCLK
FS
WAKE
SI
SCLK
CS
SO
RST
INO
IN1
CSNS
FSI
GND
LOAD
HS0
LOAD
HS1
VPWR
GND
MCU
CS
SI
I/O
I/O
I/O
A/D
Figure 1. 33984 Simplified Application Diagram
Freescale Semiconductor, Inc. reserves the right to change the detail specifications,
as may be required, to permit improvements in the design of its products.
© Freescale Semiconductor, Inc., 2007-2010. All rights reserved.
PIN CONNECTIONS
PIN CONNECTIONS
WAKE
CSNS
SCLK
VDD
RST
FSI
12 11 10 9 8
Figure 3. 33984 Pin Connections (Transparent Top View)
Table 2. Pin Definitions
Functional descriptions of many of these pins can be found in the Functional Pin Description section beginning on
page 17.
Pin
1
Pin Name
CSNS
Pin
Function
Output
Formal Name
Output Current Monitoring
Definition
This pin is used to output a current proportional to the designated
HS0-1 output.
This pin is used to input a Logic [1] signal so as to enable the
watchdog timer function.
This input pin is used to initialize the device configuration and fault
registers, as well as place the device in a low current Sleep mode.
This input pin is used to directly control the output HS0.
This is an open drain configured output requiring an external pull-up
resistor to VDD for fault reporting.
The value of the resistance connected between this pin and ground
determines the state of the outputs after a watchdog timeout occurs.
This input pin is connected to a chip select output of a master
microcontroller (MCU).
This input pin is connected to the MCU providing the required bit shift
clock for SPI communication.
This is a command data input pin connected to the SPI Serial Data
Output of the MCU or to the SO pin of the previous device of a daisy
chain of devices.
This is an external voltage input pin used to supply power to the SPI
circuit.
IN1
IN0
SO
CS
7
FS
15
HS1
SI
6 5
4
3 2
1
13
GND
TRANSPARENT
TOP VIEW
14
VPWR
16
HS0
2
WAKE
Input
Wake
3
RST
Input
Reset (Active Low)
4
5
IN0
FS
Input
Output
Direct Input 0
Fault Status (Active Low)
6
FSI
Input
Fail-safe Input
7
CS
Input
Chip Select (Active Low)
8
SCLK
Input
Serial Clock
9
SI
Input
Serial Input
10
VDD
Input
Digital Drain Voltage
(Power)
33984
4
Analog Integrated Circuit Device Data
Freescale Semiconductor
PIN CONNECTIONS
Table 2. Pin Definitions (continued)
Functional descriptions of many of these pins can be found in the Functional Pin Description section beginning on
page 17.
Pin
11
Pin Name
SO
Pin
Function
Output
Formal Name
Serial Output
Definition
This output pin is connected to the SPI serial data input pin of the MCU
or to the SI pin of the next device of a daisy chain of devices.
This input pin is used to directly control the output HS1.
This pin is the ground for the logic and analog circuitry of the device.
This pin connects to the positive power supply and is the source input
of operational power for the device.
Protected 4.0 mΩ high side power output to the load.
Protected 4.0 mΩ high side power output to the load.
12
13
14
IN1
GND
VPWR
Input
Ground
Input
Direct Input 1
Ground
Positive Power Supply
15
16
HS1
HS0
Output
Output
High Side Output 1
High Side Output 0
33984
Analog Integrated Circuit Device Data
Freescale Semiconductor
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