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MOTOROLA
SEMICONDUCTOR
TECHNICAL DATA
MC33285
HIGH SIDE TMOS DRIVER
SILICON MONOLITHIC INTEGRATED CIRCUIT
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Automotive Dual High Side TMOS Driver
The MC33285 is a dual high side TMOS driver designed for use in the harsh automotive switching applications. The purpose of the MC33285 is to drive two power n-channel FETs in a high side application with an inductive load. The application in an automotive environment requires the capability of withstanding high voltages and load dump transients. The MC33285 is able to withstand reverse battery conditions at selected pins. It protects the n-channel power FET on OUT1 under over current condition. This device has one input to control both stages on or off. *Temperature Range from -40 to +125 C C *PWM Capability *Power TMOS # 1 Over-Current and Short-Circuit Protection *Voltage Range 7V to 40V *Extended Temperature Range from -40 to 125 C C *Load Dump Protected *Over Voltage Detection and Activation of OUT2 during Overvoltage *Single Input Control for both Output Stages *Capacitor Value of 100nF Connected to Pin CP *Analog Input Control Measurement Detection *OUT1 LOAD leakage measurement detection
PIN CONNECTIONS
SRC OUT1 DRN OUT2
1 2 3 4 8 7 6 5
IN GND VCC CP
ORDERING INFORMATION
Device MC33285D Temperature Range C C -40 to +125 Package SO8
Block Diagram And Typical Application
V IGN Kl.30 CP
VCC
C CP
+ VREF Load Dump Detection IN
THRIN2
S
R tLDdet
Oscillator and Divider
Charge pump
Bandgap Rthr
DRN
ION2
ION1
tOUT2ect RQ + + OUT2 Activation Time S IOUTN2
OUT2
V OUT2-V DRN > V TH2
OUT1
V OUT1-V SRC > V TH1
THRIN1
GND OC Detection
IOUTN1 RQ S tOCdet start tOCdet OCPC
M + SRC
This document contains information on a new product under development. Motorola reserves the (c) Motorola,Inc 1999 right to change or discontinue this product without notice.
Rev 2.4
MC33285
MAXIMUM RATING
Rating Maximum voltage at pins OUT1 OUT2 Maximum voltage at pin CP Input voltage V i at DRN Input voltage V i at SRC Input voltage at pin VCC Input Voltage at pin IN. Condition : -2VELECTRICAL CHARACTERISTICS. (T A from -40 C to +125C, Vcc from 7V to 20V, unless otherwise noted)
Characteristic Symbol Min Typ Max Unit
OVERVOLTAGE AND OVERCURRENT
Load Dump Detection Time Load Dump Activation Time Error Voltage Threshold Overcurrent Detection Time tLDdet tOUT2act VDRN - VSRC tOCdet 250 300 1.12 520 800 400 460 550 620 1.44 1080 s ms V s
SRC PIN 1
Leakage Current Leakage Current Detection Time ILCdet tLCdet 15 130 30 200 50 270 mA s
DRN PIN 3
Operating Current (7VOUT1 PIN2, OUT 2 PIN 4
Output On Voltage. Charge Pump ON Turn off current, Vout >0.5V Turn On Time, OUT1: 8nF,10 ; OUT2: 16nF,10 - 7V < Vcc < 10V, Vout > Vcc+7 - 10V < Vcc < 20V, Vout > Vcc+11 Von Ioutoff ton 1.5 1.5 66 110 Vcc+15 154 V A ms
VCC PIN 6
Supply Voltage Range Quiescent Supply Current at Vcc = 20V Vcc Icc 7 40 10 V mA
IN PIN 8
Input Low Voltage OUT1 Input High Voltage OUT1 Input Hysteresis OUT1, OUT2 Input Pull Down Current, 0.7VMC33285
MOTOROLA
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MC33285
Turn On Characteristics The power FETs are turned on by charging their gate capacities with a current flowing out of pin OUT1 and OUT2. During PWM, the values of table below are guaranteed. They are measured with 8nF on OUT1 and 16nF on OUT2. - test condition : V IN : ramp 0V to 2.5V or 2.5V to 5V.
Figure 1. Turn-on Behaviour
5V IN 2.5V IN THRIN2 THRIN1
VCCP
V OUT1 VVCC +7V
VOUT2
20ms
VOUT2
2.5V IN 0V VOUT1max IN
5V
2.5V VOUT2 max
V OUT1
0V
0 ton1 ton2 ton3
VOUT2
0V
0 ton1 ton2 ton3
Table 1 Turn on behaviour Voltage V VCC 7V < V VCC < 10V 10V < V VCC < 20V 20V < V VCC < 40V Minimum V OUT1,OUT2 after ton1 = 100sec VVCC - 0.7V VVCC - 0.7V VVCC - 0.7V Minimum V OUT1,OUT2 after ton2 = 1.0msec VVCC + 5.95V VVCC + 9.35V Minimum V OUT1,OUT2 after ton3 = 1.5msec VVCC + 7V VVCC + 11V
The output voltages at OUT1 and OUT2 are limited by controlling the current sources I on1, I on2 to avoid currrent flowing through the external or the internal zener diode . If Vcc + Vth (threshold voltage) is reached , the current sources are turned off. - threshold V TH1 for OUT1 output voltage control : 7V < V TH1 < Vz - threshold VTH2 for OUT2 output voltage control : 7V < V TH2 < 15V Turn off characteristics The power FETs on OUT1 and OUT2 are turned off by discharging the gate capacity with the constant discharge current I OUToff . - discharge current I OUTxoff : IOUTxoff = 110A condition : V OUTx > 0.5V ( V IN < VTHRxIN ) Test conditions for switching off the power FETs : - 1. IN open - 2. Stages disabled via pin IN - 3. Stage OUT1 disabled by an over current error
MC33285
MOTOROLA
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MC33285
FUNCTIONNAL DESCRIPTION Introduction The MC33285 contains only one charge pump for two outputs.The outputs OUT1 and OUT2 are switched on and off by the input IN .There are three ways to control the outputs: OUt1 can be switched alone , they can be switched together or OUT2 can be switched when OUT1 is already on .In the last case , the voltage drop on OUT1 when charging OUT2 is limited . The external capacitor CCP connected to pin CP is used to store the charge continuously delivered by the charge pump . The voltage on this pin is limited to a maximum value V CPmax . Both outputs are sourced with a constant current from CCP to switch them on . In addition , the gates of the power FETs are precharged from VCC to prevent CCP from being discharged by a voltage on OUT1 or OUT2 which is still lower than VVCC.The values of the output voltages are limited to VOUT1max and VOUT2max The power FET on OUT1 is protected againts an exceeded gate-source voltage by an internal zener diode. Channel 1 allows to protect the n-channel power FET on OUT1 under over current condition. The drain-source voltage of the FET on OUT1 will be checked, if the channel 1 is switched on. The internal error voltage threshold determines the maximum drain-source voltage that allows the power FET to stay in the on state. If the measured drain-source voltage exceeds the internal error voltage threshold, the output of the Over Current Protection Comparator (OCPC) is enabled. If the output of the OCPC is active longer than tOCdet , the output OUT1 is switched off . After switching off the power FET on OUT1 by an over current condition, the power FET can only be turned on again by the input IN. When switching off the power FETs their gate capacities are discharged by a constant currennt I OUToff IF the input IN is disconnected, the MC33285 outputs OUT1 and OUT2 are in the off state. If overvoltage occurs on pin DRN for a time period longer than tLDdet , then OUT2 is switched on for the time t OUT2act . In overvoltage condition OUT1 is off if IN is below Vih. Internal Zener Diode An on-chip zener diode is placed between OUT1 and SRC. Design guarantees that V Z > VTH1 - zener clamping voltage between OUT1 and SRC : VTH1 < VZ < 20V PWM capability The CPIC2 is PWM capable on OUT2. The loss of charge on Ccp when switching on OUT2 is refreshed until the start on the next PWM cycle to a value which is sufficient to guarantee the specified turn on behaviour. The PWM capability is measured with a test circuit and load conditions - PWM cycle : period T = 20ms ; OUT2 is switched on from 10% to 90% of T . - Test condition : VIN : ramps 2.5V to 5V according to PWM cycle defined above. Crosstalk between OUT1 and OUT2 If output OUT2 is switched on while OUT1 is already on, the voltage drop that occurs on OUT1 is limited. Voltage drop on OUT1 : 10V < VVCC < 20V : OUT1 not below V VCC + 7V 7V < VVCC < 20V : OUT1 not below VVCC + 7V Each time OUT1 is switched on, a current ILCdet is sourced out of pin SRC for the time tLCdet to check if there is an external leakage current on that node in the application. The high side switch on OUT1 is turned on only if the test is successful."
MC33285
MOTOROLA
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MC33285
Motorola reserves the right to make changes without further notice to any products herein to improve reliability, function or design. Motorola does not assume any liability arising out of the application or use of any product or circuit described herein ; neither does it convert any licence under its patent rights of others. Motorola products are not authorized for use as components in life support devices or systems intended for surgical implant into the body or intended to support or sustain life. Buyer agrees to notify Motorola of any such intended end use whereupon Motorola shall determine availability and suitability of its products for the use intended. Motorola and are registered trademarks of Motorola, Inc. Motorola, Inc. is an Equal Employment opportunity/Affirmative Action Employer.
MC33285
MOTOROLA
5

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