Austria Mikro Systeme International AG AS8401 Multipurpose control ASIC for OMNIFET Data Sheet Multipurpose control ASIC for OMNINET – Data Sheet AS8401 Austria Mikro Systeme International AG Key Features • • • • • • • • • • Multipurpose control ASIC for OMNIFET (SGS Thompson intelligent power FET family) Contains one channel on-chip Applicable in low or high side switch circuits Supply voltage range 10V – 60V Up to +/- 3V potential difference between system’s digital ground and power ground possible. Current controlled interface Provides load circuit surveillance and fault back signal Typical rise time shorter then 2.4us Typical fall time shorter then 3.8us 8 pin SOIC Package General Description The ASIC’s purpose is to drive one OMNIFET n-channel power FET device. (OMNIFET is a trademark of SGS-THOMSON). The OMNIFET’s integrated protection circuits (current limitation, over temperature protection, ...) are supplied via the OMNIFET’s gate input. Thus in the OMNIFET’s on-state, a DC gate current of 0.5mA is required. In a failure case (e.g. excessive temperature) an internal resistor of about 100Ω is connected between the OMNIFET’s gate and source. This state is used to detect errors by the controlling ASIC. The control ASIC’s standard application is in the use as a high side or low side switch (selectable) in a 24V-supply system, where the functionality is guaranteed up to a maximum driver voltage of 55V. In the load dump case (VTR = 60V, Pulse duration about 5ms, 5 pulses) the ASIC remains functioning (function state A) with modified parameters (rise times and fall times). The ASIC contains one driver circuit (OMNIFET driver) and realises the following functions: • Current controlled on switch / off switch with defined rise, fall and delay times (programmable externally at the control input), that is usable as a high side or low side switch. • Automatic mode change between low side and high side use. This allows processing both, relatively low driver voltages (up to 25V, low side switch) and high driver voltages (up to 60V, high side switch) by detecting the present driver voltage related to OMNIFET’s source potential. • Error detection for the OMNIFET and generation of an error status signal. • Gate to source voltage limitation for the OMNIFET to a maximum of 13V (OMNIFET protection). • Floating ground interface between the controlling processor (control and status signal) and the driven OMNIFET; provided by separation of digital and power ground. The OMNIFET’s source potential is the ASIC’s ground. • Power reduction in the off-state (Supply current falling to less than 80µA after switching the ASIC off). The driver can be used as low or high side switch. The control and the fault back signal are realised with current sources in order to guarantee the separation of digital ground (of the processor) and power ground (at the load circuit). This is a safety function for a broken ASIC ground line and it fulfils EMC demands. Rev. A December 1999 Page 2 of 11 Multipurpose control ASIC for OMNINET – Data Sheet AS8401 Austria Mikro Systeme International AG In applications as a high side driver the OMNIFET’s source is connected to the ASIC ground, which switches together with the load circuit. Changes in the ASIC’s ground potential of up to 58V, and rise and fall speeds of up to 58V/µs are permitted. Functional Description Block diagram Figure 1: Block diagram of the AS8401 Description From the functional view the chip can be divided into the following units: A driving circuit, which implements a current-controlled switching of the OMNIFET with current pulses of approximately +30 mA, and makes the following further functions available: • Detection of the operating condition of the OMNIFET and generation of an error status signal (Output of a current of approximately 0.5 mA in the event of an error) • Defined delay of the switching-on-impulse of approximately 2.0µs and implementation of a delay of the switch-off-impulse of smaller than 0.5µs • Defined (current-controlled) rise/fall times of approximately. 2.0µs/1,0µs • Disconnection of the switching-on-impulse after approximately 5,0µs and connecting a current source of approximately 3 mA whilst the OMNIFET is switched on for the supply of the OMNIFET’s protective circuits and error recognition • Current sinking at the OMNIFET drive pin of up to 30 mA during the off state ensures a safe off status. Rev. A December 1999 Page 3 of 11 Multipurpose control ASIC for OMNINET – Data Sheet AS8401 Austria Mikro Systeme International AG 1. Automatic mode recognition / mode switching, which is controlled by detection of the driver voltage VTR related to the source potential: • Operating as a low side switch (mode1), the driver voltage is approximately 10V and the point of switching is approximately 25V. • When the AS8401 operates as a high side switch, during the transition of the OMNIFET to conduction, provided that the ASIC’s supply voltage, VTR, remains constant, the ASIC’s output current should be maintained. 2. A bandgap stabilised 5V voltage regulator, which generates the supply voltage for the digital control section and all the voltage references 3. A floating ground interface to the controlling processor (pin IN), comprised of a reference current supply and a general current supply, which implements the following functions: • Generation of a logic voltage signal from the ground-free input current at the pin IN • In on-state there are further derived currents for the production of the delay and rise/fall times of the driver from the input current at the pin IN • After the OMNIFET has been switched off and an additional time delay, the control ASIC enters power down mode. During power down the current consumption is 80µA or less. The time delay is necessary to ensure fast comparator operation in order to complete the power down sequence. 4. A time-delayed power down circuit for the control of the generation of supply current (see point 4) 5. Voltage delimitation which limits the voltage between gate and source of the OMNIFET to 13V ±1,0V (Protection of the OMNIFET). The ASIC controls the OMNIFET between gate and source (in particular also when it is used in high-side-switch applications). The operating condition in which the source potential is more positive than the gate potential, not permitted for the OMNIFET, is avoided. The use of the source potential of the OMNIFET as ASIC ground for the ground free coupling between ASIC and the processor causes fast variable ASIC ground potential during the switching operation particularly when the AS8401 is used in high side switch applications. The size of the switching-on pulses and switching-off pulses and thus the rise and fall times with given gate-source capacities of the OMNIFET can be programmed by an external resistance RIN, which determines the input current at the pin IN, within certain limits. The switching time varies approximately in inverse proportion to the current IIN at the pin IN. Thereby it is possible to adapt the AS8401 to the particular requirements of the OMNIFET (taking into account gate source capacitance and required delay/transition times) within certain limits (this adjustment range is not constituent of these Device Specification). This adaptability is limited by the possible range of the current at the input pin IN. Rev. A December 1999 Page 4 of 11 Multipurpose control ASIC for OMNINET – Data Sheet AS8401 Austria Mikro Systeme International AG Definition of the logic signals Symbol Logic meaning Level meaning IN Control input for the driver, the input is current controlled, i.e.: Ü a) appropriate driver output goes a) According to to a current from IIN= -0,1 mA 0,1mA to DGND externally prohigh (according to VOUT = VTR) duced Ü b) appropriate driver output goes b) According to no current (< 5 mA) IIN = 0 low (according to VOUT = VSOURCE) Error at the OMNIFET during the onSTAT Accumulated error status signal for status (signal is valid after terminathe controlled OMNIFET, tion of the switch-on procedure) the output is current controlled, i.e.: a) fault condition according to a current from 0,35 mA to 0.5 mA ISTAT = -0,5mA Ü a) an error of the OMNIFET during from the ASIC to DGND the on-status, b) normally operation according to no current Ü b) normal operation or off-status of ISTAT = 0 the OMNIFET Electrical Characteristics Absolute Maximum Ratings (Non Operating) SYMBOL VTR VPGND VDL PARAMETER DC Supply Voltage MIN -0.5 V IINmax VINA Maximum Input Current Digital input level Tstrg Storage Temperature Tsold Soldering Temperature tsold H ESD Soldering Time Humidity 5% Electrostatic Discharge 1000 V Load Dump Voltage MAX 55 V NOTE 60V DIN 40839 vol. 2: 5 pulse, 500ms with Ri = 2 Ohm VIN < VInmin respectively VIN > VTR -30 mA 30 mA VPGND 0.3V -55 oC 55V 150 oC 260 oC 10 sec 85 % 1) Reflow and Wave HBM: R = 1.5 kΩ , C = 100 pF Note: 1) 360 oC and 3s for manual soldering Rev. A December 1999 Page 5 of 11 Multipurpose control ASIC for OMNINET – Data Sheet AS8401 Austria Mikro Systeme International AG Recommended Operating Conditions The following values are valid for a temperature range from –40 to 105°C and a supply voltage range VTR from 10V to 42V. If the supply voltage VTR rises above 42V and stays below 60V (load dump case) the circuit stay fully functional with different parameters. In every case it is guaranteed, that the switch-off-delay is 600ns shorter than the switch-on-delay. SYMBOL PARAMETER Static parameters Driver circuit VTR Driver voltage VCC Chip internal 5V power supply IVTRoff Leakage current to power ground (PGND) in the off state MIN 10V 4.7V TYP MAX NOTE 1) 5.0V 42V 5.7V 80µA VTR = 10V, Low side switch application, off state, IIN = 0A, T = 27OC VTR = 34V, High side switch application, off state, IIN = 0A, T = 27OC VTR = 42V, High side switch application, off state, IIN = 0A, T = 105OC VTR = 10V, on state, IIN = 100µA 80µA 100µA 150µA IVTRon Current consumption in on state IOUToff Peak switch current of the driver in the switch-off phase IOUTon Peak switch current of the driver in the switch onphase IOUTN Output current of the “normal-condition“ in the onstate IOUTF Output current of the “fault condition“ in the on-state Vsat normal Saturation voltage of the “normal-condition“ in the onstate Vsat fault Saturation voltage of the “fault-condition“ in the onstate VOUT/Source Output voltage limitation between OUT and SOURCE Control input IN IINon Input current of the control signal for the on-state IINoff Input current of the control signal for the off-state Status output STAT ISTATonf Output current of status pin of the error case (fault condition) for the on-state ISTATonn Output current of status pin of the normal condition for the on-state Rev. A December 1999 3mA External using not allowed 20mA 50mA 2) -60mA -30mA 3) 0.3mA -30mA 4) 2mA 4mA 0.5V 2V 12V 14V 5) 6) -100µA -5µA 0 -1.2mA -0.5mA -50µA 5µA Page 6 of 11 Multipurpose control ASIC for OMNINET – Data Sheet AS8401 Austria Mikro Systeme International AG Recommended Operating Conditions (continued) SYMBOL PARAMETER Dynamic parameters TRISE Rise time TFALL Fall time TPDon Switch on delay TPDoff Switch off delay TSP Duration of the switch-on current pulse MIN TYP MAX 5.0µs 2.4µs 3.8µs 3.9µs 4.0µs 7.0µs 0.75µs 4.0µs NOTE Note: 1) The maximum driver voltage VTR at full function it is VTR = 42V. At VTR = 60V in the load dump case all defined functions are staying valid (function state A). In this state it is possible that some times some parameters are different from the specified value, but in every time the switch off delay is shorter then the switch on delay. 2) Valid for an input current IIN = 0A. This possibility of the output OUT is valid the off state. 3) Valid for an input current IIN = 100µA. This possibility of the output OUT is valid the on state. 4) This is the input current of the OMNIFET in the on-state 5) This is a chip internal dynamical limitation of the output voltage. 6) Correspondent with the output current of the control circuit. The capacity on the pin IN has to be low (CPIN extern < 1 pF). The tolerance of this current controls the switch timing. Rev. A December 1999 Page 7 of 11 Multipurpose control ASIC for OMNINET – Data Sheet AS8401 Austria Mikro Systeme International AG Pin-out Information Pin Description n.c. 1 8 VTR IN 2 7 OUT n.c. 3 6 SOURCE STAT 4 5 VCC AS 8401 SOIC-8 (Top view) Figure 2: Pin-out AS8401 Pin list Pin No. 1 2 3 4 5 6 7 8 Pin Name n.c. IN n.c. STAT VCC SOURCE OUT VTR Rev. A December 1999 Type Description Not connected Input Control input of the driver Not connected Output Output for state signal ( error state) Output Internal supply for logic (5V) Ground Source of the OMNIFET and ground of the ASIC Output Driver output (gate of the OMNIFET) Supply Supply of the Driver Page 8 of 11 Multipurpose control ASIC for OMNINET – Data Sheet AS8401 Austria Mikro Systeme International AG Application Schematic High side switch Figure 3: AS8401/OmniFet as high-side switch Low side switch Figure 4: AS8401/OmniFet as low-side switch Rev. A December 1999 Page 9 of 11 Multipurpose control ASIC for OMNINET – Data Sheet AS8401 Austria Mikro Systeme International AG Grounding concept In Figure 3 and 4 two possible application circuits for the AS8401/OmniFet were shown. For a better understanding of this two application circuits in Figure 5 a Grounding/Supply-concept for this two circuits is shown. Figure 5: AS8401/OmniFet application circuits grounding/supply-concept Rev. A December 1999 Page 10 of 11 Multipurpose control ASIC for OMNINET – Data Sheet AS8401 Austria Mikro Systeme International AG Package Information Package : SOIC 8 small outline SOIC 8 AS8401 YY WW XXX SOIC 8 small outline Marking Chip number Year of Production Week of Production Assembly-ID (Dimensions in mm) min. nom. 1,6 1,6 0,1 0,15 1,40 1,5 0,4 0,4 0,19 0,2 4,8 4,9 3,8 3,9 1,27 BSC 5,8 5,99 0,25 0,33 0,41 0,64 0° 5° A A1 A2 B C D E e H h L α max. 1,7 0,3 1,6 0,5 0,3 5 3,99 6,2 0,41 0,9 8° h x 45° α C L A A2 seating plane 7 B D 3 e 6 4 AS8401 R 5 YYWWXXX A1 2 1 8 E H Figure 6: Physical package dimensions Copyright 1999, Austria Mikro Systeme International AG, Schloß Premstätten, 8141 Unterpremstätten, Austria. Telefon +43-(0)3136-500-0, Telefax +43-(0)3136-52501, E-Mail [email protected] All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, without the prior permission in writing by the copyright holder. To the best of its knowledge, Austria Mikro Systeme International asserts that the information contained in this publication is accurate and correct. Rev. A December 1999 Page 11 of 11