MC33288
Solid State Relay for Automotive
Flasher Applications
PIN ASSIGNMENT
Simplified Application Schematic
DH SUFFIX
1
2
3
5
4
6
7
8
9
10
1
2
3
5
4
6
7
8
9
20
1
1
1
1
1
1
1
1
1
Cur R
IN-1
NC
DNC*
Out-1
Out-1
Out-1
NC
NC
IN-2
Wlp
Status
NC
Out-2
Out-2
Out-2
NC
NC
21
21
Vbat
Vbat
GND
Heat sink
DNC*
MCU
OUT-2
OUT-1
MC33288
VBAT
IN-1
IN-2
ST
Cur R
Gnd
21W
5W
Trailor
Car left side lamps
Car right side lamps
21W
21W
5W
21W
5W
5V
21W 21W
5W
A/D
I/O
I/O
I/O
Buzzer
Warning
switch
Turn
switch
dashboard
direction indicator
dashboard
trailer indicator
+
-
Static Flasher
Wlp
1.2W
10k
5V
HSOP20 Package
Device
Operating
Temperature Range
Package
MC33288DH
TA=-40 to +125C
HSOP20
MC33288DHR2
TA=-40 to +125C
HSOP20
CASE 979-04
ORDERING INFORMATION
SOLID STATE RELAY FOR
AUTOMOTIVE FLASHER
APPLICATIONS
SEMICONDUCTOR
TECHNICAL DATA
Semiconductor Technical Data
MOTOROLA
Order Number: MC33288/D
Rev. 4.8, 06/2001
Advance Information
This document contains information on a new product. Specifications and
information herein are subject to change without notice.
Motorola, Inc., 2001. All rights reserved.
TM
This device is a Dual High Side Power Switch dedicated for automotive flasher
applications. In comparison with mechanical solutions, this device offers higher
reliability as well as protection and diagnostic features.
The device consists of two 25m
Rdson fully protected high side switches, in a
surface mount power package. It interfaces directly with a microcontroller and
includes a current recopy function in order to allow the detection of a failed lamp in
the application.
Designed for Automotive Flasher Applications
Junction Temperature Range from - 40
C to 150C
Operating Voltage Range from 8V to 35V
Maximum Breakdown Voltage greater than 40V
Protected in case of loss of ground
Surface Mount Power Package
25m
Rdson per Channel at 25C
8Amps Nominal Current per Channel
1.2W Warning Lamp Driver
Overtemperature Protection with Hysteresis
Open Load Detection in On-State
Short-Circuit Protection
Overload Current Protection
Current Recopy to Monitor Lamp Output Current
Under Voltage Shutdown
ESD Protection 2kV
Standby Current less than 10
A at V
bat
less than 14V
* Do Not Connect
MC33288
PINS FUNCTION DESCRIPTION
Solid State Relay for Automotive Flasher Applications
2
Pin No.
Name/Function
Description
TAB V
bat
Supply Voltage
The backside TAB is connected to the power supply of the
MC33288DH. In addition to its supply function, this pin contributes to
the thermal behaviour of the device by conducting the heat from the
switching MOSFET to the printed circuit board.
6,7,8
13,14,15
OUT1
OUTPUT Channel 1
OUT 2
OUTPUT Channel 2
Pins 6,7,8 are the source of the output1 25mOhm MOSFET1. Pins
13,14,15 are source of the output 2 25mOhm MOSFET2. They deliver
current to the connected loads and are respectively controlled via the
IN1 and IN2 pins. These outputs are current limited and thermally
protected.
3
18
IN 1
INPUT Channel 1
IN 2
INPUT Channel 2
These are the device input pins which directly control their associated
outputs. The levels are CMOS compatible. When the input is a logic
low, the associated output MOSFET is in the off state. When input is
high, the MOSFET is turned on and the load is activated.
When both inputs are low, the device is in standby mode and its
supply current is reduced. Each input pin has an internal active pull
down, so that it will not float if disconnected.
19
Status
Status for both
Channels
The Fault output is an open drain indication that goes active low when
a fault mode (Openload, Overtemp) is detected by the device on
either one channel or both simultaneously. Its internal structure is an
open drain architecture with an internal clamp at 6V. An external pull
up resistor connected to Vdd (5V) is needed. See Functional Truth
Table.
20
Wlp
Warning Lamp Output
This pin is the source of a 3.2 Ohm MOSFET. This output is current
limited and thermally protected. It delivers current through the
connected load when both IN1 and IN2 inputs are logic high. It is usually
used as a warning lamp driver for Flasher application.
2
Cur R
Load Current Sense
The Current Sense pin deliver a ratioed amount (1/1000) of the sum
of the currents that can be used to generate signal ground referenced
output voltages for use by the microcontroller.
4, 9, 10, 11, 12, 17
NC
Not Connected
These pins are not used.
5, 16
DNC
Do Not Connect
These pins must not be connected.
11
GND
GROUND
This is the Ground pin of the device.
MC33288
Solid State Relay for Automotive Flasher Applications
3
Block Diagram and Application Schematic
FUNCTIONAL TRUTH TABLE
L = `Low level' H = `High level'X = `don't care'
NOTES :
In case of over current or short-circuit, the device will not report the fault to the status pins. The output current will be limited to the Ilim value. The device will probably
heat up and in this case the overtemperature detection will be triggered. If so, the output will be turned off and the fault will be reported to the status pins.
In-1
In-2
Out-1
Out-2
St
Normal Operation
L
H
L
H
L
L
H
H
L
H
L
H
L
L
H
H
H
H
H
H
Openload Channel 1
Openload Channel 2
H
X
X
H
H
X
X
H
L
L
Overtemp Channel 1
Overtemp Channel 2
Overtemp Channel 1 and Channel 2
H
L
X
X
H
X
X
H
L
H
L
L
X
X
L
X
X
L
L
L
L
H
L
H
L
Overcurrent or Current limit Channel 1 (note)
Overcurrent or Current Limit Channel 2 (note)
H
X
X
H
H
X
X
H
H
H
Battery
MCU
Out-1
IN-1
Left side
Out-2
IN-2
Charge
Pump
Fault
Input
Trigger
Over
Temp
Over
Current
Out-1
Out-2
GND
CHANNEL 1
CHANNEL 2
Current
Recopy
Cur R
Cr 2
Current copy
resistor
21+21+5W
Right side
21+21+5W
A/D
I/O
V
bat
Cr 1
Trailor Right side
21+5W
21+5W
Trailor Left side
MC33288
Cb
R
R
Left
Right
I/O
R
ST
I/O
R
Out-1
Out-2
Monitoring
R : 10k typical
Rcr : 500
to 1k typical
Cb : 100nF to 470nF
Rwlp : 100
typical
St-2
St-1
Rcr
Drive &
protect
Vbat
Vbat
Wlp
1.2W
IN-2
Warning Lamp
Driver
Rwlp
Open
Load
V
batc
5V
10K
MC33288
Solid State Relay for Automotive Flasher Applications
4
MAXIMUM RATINGS
NOTES :
1. EDS1 testing is performed in accordance with the Human Body Model (Czap = 100pF, Rzap = 1500
)
2. EDS2 testing is performed in accordance with the Machine Model (Czap = 100pF, Rzap = 0
)
3. During lamp inrush current.
4. Device mounted on dual side printed circuit board with 70
m copper thickness and 10cm
2
copper heat sink (2.5 cm
2
on top side and 7.5 cm
2
on down side).
5. Assuming a 150
C maximum junction temperature.
ELECTRICAL CHARACTERISTICS
(Vbat from 9 to 16V and junction temperature Tj from -40
to 150C, unless otherwise noted)
Ratings
Symbol
Value
Unit
ELECTRICAL RATINGS
Vbat Voltage with Respect to Gnd : Continuous/Pulse
Vbat
-14 to + 40
V
Out-1 & Out-2 Voltage with Respect of Gnd : Continuous/Pulse
Vout
-0.3 to 40
V
Out-1 to Vbat & Out-2 to Vbat voltage : Continuous/Pulse
Vout
40
V
IN-1, IN-2, St DC Voltage : Continuous/Pulse
Vin
-0.3 to 7
V
Cur R Voltage : Continuous/Pulse
Vcr
-0.3 to 7
V
ESD all Pins
Human Body Model (note1)
Machine Model (note2)
V
esd1
V
esd2
+/-2000
+/-200
V
V
Out-1, Out-2 Output Current : Pulse (note 3)
Ioutp
40
Amp
IN-1, IN-2, St
Iin
+/-5
mA
THERMAL RATINGS
Junction Temperature
Tj
- 40 to 150
C
Storage Temperature Range
Tst
- 65 to +150
C
Thermal Resistance Junction to Case
Rthjc
2
C/W
Thermal Resistance Junction to Ambient (note 4)
Rthja
25
C/W
Power Dissipation at Tcase 140
C (note 5)
Pd
5
W
Description
Symbol
Characteristics
Unit
Conditions
min.
typ.
max.
Nominal Operating Voltage
V
bat
9
16
V
Functional Operating Voltage
V
bat
8
35
V
Under Voltage Threshold
V
uv
6
7
8
V
Vbat Standby Supply Current
I
stdby
1
10
A
V
bat
<14V & V
in
= 0V,T
j
<125
C
Supply Current in On State
I
on
8
20
mA
IN-1 & IN-2 @3.5V, no fault,
Vbat<14V,T
j
<125
C
Drain to Source on Resistance
R
dson
20
25
m
Iout =4A, V
bat
> 9V & T
j
= 25
C
Drain to Source on Resistance
R
dson
30
40
m
Iout = 4A, V
bat
> 9 & T
j
= 150
C
High Current Limitation
I
lim
30
A
Vout > 1V
Short Circuit limitation
I
lim
4
A
Vout < 1V, Tj=25C
Hot Openload Threshold
I
ol
1
A
Vbat to Output Breakdown Voltage
V
dss
40
V
In-1 and In-2 @ 0V, Vout = 0,
Iout -0.25mA
Vbat to Out-1 : Leakage Current
I
out-leak
10
A
Vin-1 =0V, Vbat =35V, Vout-1=0V
MC33288
Solid State Relay for Automotive Flasher Applications
5
Vbat to Out-2 : Leakage Current
I
out-leak
10
A
Vin-2 =0V, Vbat =35V, Vout-2=0V
Vin-1, Vin-2 : Input Voltage Low Threshold
V
il
1.5
V
Vin-1, Vin-2 : Input Voltage High Threshold
V
ih
3.5
V
Vin-1, Vin-2 : Input Voltage Hysteresis
V
ih
0.4
0.7
0.9
V
Vin-1, Vin-2 : Input Current
I
in
18
40
A
Vin-1, Vin-2 = 3.5V
Status Output Voltage
Vst
0.5
V
Ist = 1mA; Output in Fault
Thermal Shutdown
T
shut
150
C
Thermal Shutdown Hysteresis
T
hyst
10
C
Current Recopy Ratio
Cr
1/1000
Vout>Vbat -1V, Iout from 2A to 4A
Tj -40
C to 105C, Vbat 9 to 16V
Current Recopy Ratio Accuracy
Cr-ac
-10
10
%
Vout >Vbat -1V, Iout from 2A to 4A
Tj -40
C to 105C, Vbat 9 to 16V
Extended Current Recopy Ratio
Crex
1/1000
Vout >Vbat -1V, Iout from 1A to 8A
Extended Current Recopy Ratio Accuracy
Crex-ac
-20
20
%
Vout >Vbat -1V, Iout from 1A to 8A
Current Recopy Clamp Voltage At 10mA
Vclst
5.5
7
V
Nominal Flasher Frequency Operation
Ffl
1.5
Hz
Frequency Operation
Fop
100
Hz
Nominal Flasher Duty Cycle Operation
DCfl
50
%
Wlp output Drain to Source on Resistance
RW
on
3.2
Iout =100mA, V
bat
> 9V & T
j
= 25
C
Wlp output Drain to Source on Resistance
RW
on
5
Iout =100mA, V
bat
> 9V & T
j
= 125
C
Wlp output Current Limitation
IW
lim
500
mA
Vout =0V
Wlp Thermal Shutdown
TW
shut
150
C
Maximum Output Positive Slew Rate
Tr
0.01
0.3
2
V/
s
load = 6
Maximum Output Negative Slew Rate
Tf
0.01
0.3
2
V/
s
load = 6
Turn On delay time
Tdon
1
30
200
s
load = 6
, from Vin/2 to 10% Vout
Turn Off delay time
Tdoff
1
40
200
s
load = 6
, from Vin/2 to 90% Vout
Description
Symbol
Characteristics
Unit
Conditions
min.
typ.
max.
MC33288
DEVICE DESCRIPTION
Introduction
The MC33288DH is a dual high side switch with
appropriate control, protection, and diagnostic features
dedicated to automotive flasher applications. The device
consists of two independent 25m
power switches and an
additionnal 3.2 Ohm high side switch capable of controlling a
1.2W warning lamp. It interfaces directly with a microcontroller
and the package used is a HSOP20 power small outline, 20
pins. The MC33288 incorporates a status pin and a load
current sense capability.
Power Supply
The MC33288 can be directly connected to the supply
line. In standby mode (In-1 & In-2 @ OV), the supply current is
less than 10
A for Vbat supply voltage below 14V. This
feature allows a very low supply current on the battery when
the car is idle or parked.
During off state, the current recopy pin and the status pins
are in high impedance.
In case of loss of (digital) ground, the power MOSFETs
turn off in order to safely tie the load current to zero.
Nominal Voltage and Transient Operation
The nominal operation voltage is from 9 to 16V. The
MC33288 is functional over a larger voltage range from 8V to
35V. The technology used for both power and analog circuitry
sustains 40V DC voltage.
Reverse Battery
The MC33288 is self protected against reverse battery up
to -14 Volts in a continuous mode. When a negative battery
voltage arises, the MOSFETS are internally turned off. The
load current flows in the body diode of each MOSFET. The
power dissipation within the MC33288DH is then Vf x Iload,
where Iload is the total current set by the loads and Vf is the
forward body diode voltage. Vf is 0.5V typical at 150C and
decreases with temperature with a drop of -2mV/C.
Power Output Switches
The device has two independent high side switches. Each
switch is realised with an N-channel power MOSFET and
includes current and temperature sensing circuitries. The
MOSFET gates are driven by analog circuitry which includes
charge pump and fault detection. A specific feature of this
device is the output current recopy.
Each output has a 25m
Rdson max at 25C. The Rdson
value reaches 40m
at 150C junction temperature. Each
output has a parasitic drain to source diode, inherent to the
technology. This diode can sustain as much current as the
MOSFET. This diode is reversed biased during normal
operation of the MOSFET and is forward biased during
reverse battery or negative transient pulses.
The output MOSFET can each drive 8 Amps nominal. This
maximum current condition occurs when up to three 21W
lamps and two small 5 or 7W lamps are connected on each
channel, at higher Vbat voltage specification. This is the case
when a trailor is attached to the car. As the flasher can operate
in warning or hazard operation mode with its two channels on,
the MC33288 can drive 16 Amps total.
When lamps are turned on, the inrush current can reach
up to 6 times the nominal lamp current. For this particular
application, the total inrush current can reach 6 time 8 Amps,
that is up to 48Amps per channel. The 48Amps value will only
occur at the first lamp turn on. In order to optimise the total
system,(MC33288, printed circuit board, wiring, fuse etc.) the
device incorporates a current limitation at 30 Amps typical.
This mean that the really first inrush current will be clamped at
30 Amps. The second lamp turn on of the flashing cycle will
not see any clamping as the lamps have been heated up in the
previous cycle.
In-1 and In-2 are the two inputs of the device, connected to
a microcontroller I/O ; they are CMOS compatible. When
these inputs are in low state, the device is in standby mode.
When any of the inputs are switched to a high level, the
associated output MOSFET is turned on.
Status
The device has a single status pins which reports an over
temperature and an openload condition in the device. This pin
is an open drain structure and needs an external pull up
resistor. The device incorporates overtemperature sense on
each output MOSFET in order to independently protect each
output. But , the report of the overtemperature is done through
one single status pin called Status, in order to minimise the
number of I/O connection of the MCU.
Open Load Function
The open load detection is active during the ON phase (Hot
open load detection). An amplifier measures the differential volt-
age between V
bat
and V
out
.
When the load current is below 1A, the open load circuitry will
pull down the status output. If the open load condition is present
before the device turn-on, the status will be pulled down after a
delay due to the rise time of the output.
Current Recopy Function
Flasher application needs to detect failed lamp. The
system must detect one 21W lamp failing, in the flasher
application only, without a trailor. The MC33288 has an output
current recopy function which recopies on the Cur R pin a
portion of the output current. Each channel is connected to the
same Cur R pin as the system have to operate in the flasher
mode only and not in the warning operation.
The MC33288 provides a current recopy of 1/1000 of the
main output current, either output left or right. The recopy
function has its higher accuracy of +-10% in the usual
operation range and an accuracy of +-20% in the total
operating range. This allows a precise detection of one 21W
lamp, but also the detection of additional lamps in case of
trailor connection.
An external resistor must be connected to the Cur R pin
and then tied to a microcontroller A/D input for analog voltage
measurement. The Cur R pin is internally clamped to protect
the MCU A/D input.
Warning Lamp Driver
The warning lamp driver is a 3.2 Ohms Rdson max High
Side MOSFET to control the 1.2W dashboard warning lamp.
This output is current limited and thermally protectedactivated
only in the warning mode. It is turned on by activation of both
right and left inputs (IN1 and IN2)
Package
The device is assembled into a power surface mount
package. This package offers high thermal performances and
high current capabilities. It offers 10 pins on each package
sides and an additional pin which is the package heat sink ,
called pin 21. The heak sink acts as the MC33288 power Vbat
connection.
MC33288
Solid State Relay for Automotive Flasher Applications
7
Soldering Information
This device is packaged in a Surface Mount Power
package indended to be soldered directly on the Printed
Circuit Board.
This device was qualified according to JEDEC standards
JESD22-A113-B and J-STD-020A with the reflow conditions
applicable for packages with thickness above 2.5mm :
Convection 220C +5/-0C
VPR 215-219C
IR / Convection 220C +5/-0C
The maximum peak temperature during the soldering process
should not exceed 220C (+5C/-0C). The time at maximum
temperature should range from 10 to 40s max.
Thermal Management
The junction to case thermal resistance is 2
C/W
maximum. The junction to ambient thermal resistance is
dependent on the mounting technology and the addition of
heat sink. One of the most commonly used mounting
technique consists in using the printed circuit board and the
copper lines as heat sink.
Figure 1. Printed Board Layout Example (not to scale)
Figure 1 shows an example of printed circuit board layout.
It has a total of 10cm
2
additional copper on two sides (2.5 cm
2
on the top side and 7.5 cm
2
on the down side).
With the above layout, thermal resistance junction to ambient
of 25
C/W can be achieved, this value being splitted into :
junction to case : Rthjc1 = Rthjc2 = 2
C/W
case to ambient : Rthca = 23
C/W.
Lower value can be reached with the help of larger and
thicker copper metal, higher number of thermal via from top to
down side pcb and the use of additional thermal via from the
circuit board to the module case.
Steady State Thermal Model
The junction to ambient thermal resistance of the circuit
mounted on a printed circuit board can be splitted into two
main parts : junction to case and case to ambient resistances.
A simplified steady state model is shown in figure 2.
Figure 2.
Simplified Thermal Model (Electrical Equivalent)
Transient Thermal Model
A more complete model including thermal capacitance is
proposed in figure 3.
Figure 3. Transient thermal model
This gives a thermal impedance versus time (figure 4), which
has been determined with the printed circuit board shown in
figure 1.
Figure 4. Junction to ambiant Thermal impedance
This figure shows that the steady state is reached after about
10 minutes. It also clearly shows that the device can dissipate
almost twice the power within one minute compared to the
maximum allowed power dissipation in steady state.
Down side pcb
Top side pcb
2 cm
2
8 cm
2
HSOP20
external pcb (4x4 cm)
Thermal
via from
top to down
side pcb
Rthca
Rthjc2
Rthjc1
Chan 1 Junction
Ambient Temp Node
Chan 2
Case Temp Node
Chan 2 Junction
Temp Node
Temp Node
Chan 1
Switch
Chan 2
Switch
Power (W)
Chan 1
Power (W)
(1.0A=1W of
(1.0V=1
C)
(Volts represent Die
Surface Temperature)
(1.0
=1C/W)
Power Dissipation)
2C/W
2C/W
25C/W
AmbientTemperature
MOS1
MOS2
Control
Case
Board
Ambiant
3K/W
3K/W
3K/W
450K/W
3K/W
20K/W
6J/K
0.5J/K
4mJ/K
5mJ/K
5mJ/K
1mJ/K
3.5K/W
3.5K/W
300K/W
MOS3
30
20
10
0
0
100
200
300
400
500
600
700
800
T
h
er
m
a
l
i
m
ped
anc
e
(
C/W
)
Time (sec.)
Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty, representation or guarantee regarding the suitability
of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all
liability, including without limitation consequential or incidental damages. "Typical" parameters which may be provided in Motorola data sheets and/or specifications can and do
vary in different applications and actual performance may vary over time. All operating parameters, including "Typical" must be validated for each customer application by
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MC33288/D
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