Preliminary Data Sheet u1614 Coil Driver IC Description Features The u1614, combined with an external NMOS, is used as a low loss driver for coils, relays or magnets. You can choose between a current controlled and a voltage controlled PWM to drive the load. An external resistor is used for current controlled regulation. Two additional external resistors are necessary for the voltage-controlled PWM mode. The hold current, the overexcitation coil current and the overexcitation time are adjusted separated in both cases. The bootstrap output, with square pulses, can be used for further applications. The chip overtemperature protection is adjusted from 80 to 150 C with an external resistor. Chip overtemperature, undervoltage errors and relay status are indicated on input IN. q q q q q q q q q q q q q q q Voltage supply 8 to 45 VDC 5-V and 12-V reference voltage output Quiescent current 2 mA Output current up to 200 mA Current or voltage controlled regulation of the coil current Adjustable oscillator frequency 50 Hz to 5 kHz Adjustable hold and overexcitation coil current Adjustable overexcitation time Bootstrap output up to 2 mA Undervoltage lockout and power-on reset Overvoltage protection for the external NMOS Protection against reversed battery and EMC Adjustable chip overtemperature protection Temperature range -40C to +150C Package SOP 18 u1614AT Die u1614AX Applications q Current controlled driver for coils q PWM driver for relays Coil driver using u1614 Typical Application VDD Input 15 Mode A 6 Mode B 7 680n CTO 8 18K RCH 13 75K RCO 14 30K RREF 11 15K RPT 10 5 June 1999 IN VDD MODA VDDC MODB u1614 BOUT CTO OVP INCH OUT INCO SEN IRCR COSC INPT GND INST VREF 17 16 220n CVDDC 4 L D 2 3 output M 1 12 10n COSC RSEN 18 9 alpha microelectronics gmbh 100n CVREF Page 1/12 Page 2/12 alpha microelectronics gmbh RCH RCO INCH 13 14 MODB 7 Mode B INCO MODA IN 15 6 INST 5 Mode A Input Relay Status Input 50 500K 50 30k RREF IRCR 11 Internal Current 10 RPT 6 5 M2 S1 M3 R S 1,5 CCO 8 CTO DZ3 200k RV Mode-Logic 9V tOE- Trigger and Logic Error-Logic INPT Thermal Shutdown 50 500K 500K COSC 12 K2 1 SEN vU=20 500K Turn on / off Logic OSC 2,5V 3V 4 3 50 Frequency Control i1614 S3 Undervoltage Lockout K1 Oscillator 4 3 R S Q Latch Divider 1:4 Logic 3 4 VDD VDDC D 9 17 16 S4 S5 2 Bootstrap Reference Regulator VPSR 2 1 Prestababilization 7V for Reference VREF CREF CVDDC S6 Driver DZ2 16V D2 48V DZ1 VPSD Prestababilization 12V for Driver 18 GND OUT OVP BOUT 3 2 4 D2 RSENSE M1 D1 VDD Functional Block Diagram S2 June 1999 Pin Definition Pin Symbol Designation 1 SEN Current Sense Input 2 OVP Overvoltage Protection Output for external MOSFET 3 OUT Output 4 BOUT Bootstrap Output 5 INST Input for Status Relay 6 MODA Mode A Input 7 MODB Mode B Input 8 CTO Capacitor for Overexcitation Time 9 VREF Reference Voltage Output 10 INPT Resistor for Overtemperature Protection 11 IRCR Resistor for Current Reference 12 OSC Capacitor for Oscillator Frequency 13 INCH Resistor for Hold Current 14 INCO Resistor for Overexcitation Current 15 IN Input 16 VDDC Block Capacitor 17 VDD Supply Voltage 18 GND GND The location of pins can be changed during the development. General function and description The i1614 combined with an external N-channel power MOSFET serves for the low loss control of electrical magnetic actuators like relays or magnets and similar kinds of coils. It is especially suitable in automotive applications. The i1614 can operate either in current-mode or voltage-mode control to regulate the load current. Current-mode control The oscillator sets a latch which turns the external low-side transistor on. The load inductance is charged from the supply voltage. The load current increases until the voltage drop over the sense resistor reaches the external programmed value. Then the comparator resets the latch witch turns the external transistor off. Now the load current flows through the free-wheeling diode and remains nearly constant until the next oscillator set impulse. By changing the oscillator frequency with an external capacitor the free-wheeling duration can be varied. Voltage-mode control In case of voltage-mode control the PWM ratio is controlled in a way that the energy in the inductance remains nearly constant over a defined supply voltage range. For an optimal adaptation to the load inductance both current levels (hold / overexcitation) and the overexcitation time can be adjusted externally and independently. The /1614 has various safety functions and diagnostic functions such as overvoltage protection, undervoltage lockout, detection of broken wire or short circuit. Fault events are indicated on IN. June 1999 alpha microelectronics gmbh Page 3/12 PIN function and description VDD The u1614 is designed for a supply voltage of VDD = 8 ... 45V. The IC includes a diode in the VDD line (VFD 0.6V, VBR 400V), saving it against reversed polarity of the supply voltage. The internal diode and the pass transistor of the internal 12-V preregulator are designed for a maximum peak current of 75mA. If necessary the peak current has to be limited by an external resistor in the power supply line. The undervoltage detection disables at VDD 7.5V the push-pull output stage and the bootstrap driver. This error state is reported on the IN input with low level. Therefore is the error state in case of mode 3 with a permanent low-level input signal (turn-on) not readable. VDDC The VDDC voltage (VDD-0.6V) supplies power to the 5-V reference and 12-V preregulator providing the output driver and the bootstrap driver. Bypass this pin with a capacitor. VREF The internal 5-V reference voltage must be bypassed with a capacitor of 100nF. It supplies power the internal logic and the power-on-reset circuitry (turn-on threshold at VREF 4V). The VREF pin can provide an additional current up to 1mA to an external load. The output signals of the undervoltage detector and the power-on-reset circuitry are logically AND connected. OUT The output of the push-pull driver charges / discharges the external NMOS Transistor with up to 200mA. The maximum output voltage of the driver is 12V. OVP The OVP input is internally connected through a series of zener diodes and forward biased diodes to the OUT output. Thereby the external transistor is protected from overvoltages higher then 48V (see figure 1 and 2). If the current into the OVP input gets higher than 30A, the overvoltage function will be enabled. The internal sink transistor of the driver stage is turned off and the external transistor is turned on. If an external MOSFET with a higher breakdown voltage is used, the overvoltage protection threshold can be adjusted with an external zener diode. BOUT The bootstrap push-pull driver generates a square wave voltage (50% DC) with an amplitude of about 12V and with the same frequency as the oscillator frequency. An faster discharge of the inductance can be achieved with an additional circuitry including a voltage multiplier and a NMOS transistor( see figure 5). The bootstrap driver will controlled via the input IN. The bootstrap output shows low level in the turn-off state and in the error state. MODA and MODB Four input modes can be programmed according the following table. Open inputs will be detected as high level. Mode description MODA MODB Mode 1 AC-input and external PWM-control open / VRef GND Mode 2 AC-input and internal PWM-control GND GND Mode 3 Low active DC input and internal PWM-control GND open / VRef Mode 4 High active DC input and internal PWM-control open / VRef open / VRef IN Besides the turn-on / turn-off function the IN input serves as a status output. In case of an error event the input changes to low level (about 1V). The high-impedance input has to be connected only to an open-collector stage or open-drain stage. The high Schmitt trigger input stage detects input voltages higher than 3V as a high signal and input voltages lower than 2.5V as a low signal. An open input is interpreted as a high signal. Short transient impulses at the input are filtered by an internal RC filter with a 700-ns time constant. The maximum input voltage is 80V. The input IN is protected against negative voltages up to -80V. The input impedance can be lowered with a resistor between VDDC and IN. The input frequency and oscillator frequency have to be in a defined ratio at the dynamic modes mode 1 and mode 2. An advantage of the dynamic input control is the self detection of broken wire or short circuit on the input. Page 4/12 alpha microelectronics gmbh June 1999 According to the four input modes (programmed at MODA, MODB) are the following variants for the input control possible: Mode 1 Dynamic input control (low active), with external PWM control turn-on condition fIN > 0.6*fOSC turn-off condition fIN < 0.4*fOSC INCH, INCO, CTO = GND / low signal and SEN = open / VRef' The output stage is directly controlled from the input signal. The switch-on delay and switchoff delay are related to the phase position between input frequency and oscillator frequency and may be (1 ... 2) *TPOSC. The functions current-mode control, voltage-mode control, overexcitement, hold, and finalposition-contact detection are disabled in this mode. Mode 2 Dynamic input control with internal PWM-control turn-on condition fIN = 1*fOSC turn-off condition fIN < 0.4*fOSC retrigger condition fIN = 2**fOSC In opposite to Mode 1 the input frequency does not serve for the direct control of the output stage. Mode 1 results in a turn-on ( fIN = fOSC ) that is always combined with a switch-on overexcitation. A change to the double input frequency (fIN = fOSC fIN = 2*fOSC) causes a renewed overexcitation (refresh, retriggering). Every further refresh needs such input frequency change. The switch-on delay and switch-off delay, the delay for the retriggering, and the delay for the change back from double to simple input frequency are also directly depended on the phase position between input frequency and oscillator frequency and can be (1 ... 2) *TPOSC. After the turn-on at the input starts the current-controlled or voltage-controlled regulation. Mode 3 Static input control (low active), with internal PWM control turn-on condition high-low slope turn-off condition VInput > 4V retrigger condition high-low slope The static input control performs only the turn-on function. The input controls the output driver not direct. After turning on combined with overexcitation starts the current-controlled or voltage-controlled regulation without any delay. A refresh (retriggering) can be initiated with a short turn-on - turn-off sequence. The power supply voltage has to exist before the turn-on condition, otherwise the switch-on overexcitation will not be executed. After an undervoltage detection or chip overtemperature a high-low slope on the input has to be generated to perform a switch-on overexcitation. Mode 4 Static input control (high active), with internal PWM control turn-on condition low-high slope turn-off condition VInput < 2V retrigger condition low-high slope The mode 4 is the "inverse case" of mode 3. See mode 3. OSC The current source at the oscillator input provides a charge /discharge current of +/-50A into the external capacitor COSC and generates a triangle wave. The lower comparator threshold of the oscillator is 0.8V, the upper comparator threshold is 4V. The triangle wave is used for the voltage-controlled regulation. It is transformed into a square wave setting the latch for current controlled regulation. The following divider stage divides the oscillator frequency by 4 for the analysis of the input frequency. The i1614 is intended to use in a frequency range of 50 Hz to 5kHz. For the calculation of COSC is valid: COSC [nF] = 7710 / fOSC [Hz] CTO The capacitor CTO setting the overexcitation time TCTO up to 3s is connected to the CTO pin. The charging current for the capacitor is about 1.4A and the threshold is 4.5V. The value of the capacitor is limited to 1F. The maximum discharge time of the capacitor is 10ms. During the discharge time a renewed overexcitation is not allowed. For the calculation of CTO is valid: CTO [nF] 0.3*TCTO [ms] June 1999 alpha microelectronics gmbh Page 5/12 INCO and INCH External resistors at both inputs set the values of overexcitation current and hold current. Each internal current source provides a current of 50A. Current-controlled regulation: Both inputs are connected to GND with a resistor. The values of the resistors are the following if the oscillator levels are 4V and 0.8V. overexcitation mode: hold mode: RCO = 4000mV / 50A = 80k RCH = 800mV / 50A = 16k In case of current regulation both inputs can be also controlled by an external voltage (instead of a resistor). Supply-voltage controlled regulation: Two external resistors between the inputs INCO, INCH and the VDDC pin set the desired supply-voltage dependence for the overexcitation current and hold current (see fig. 2). In opposite to the current-mode control the voltage on the input INCH is higher than the voltage on the input INCO, e.g. maximum overexcitation (PWM = 99%): minimum hold (PWM = 1%): VINCO 830mV, VINCH 3970mV The target voltages VINCH and VINCO are compared with the comparator to the oscillator triangle wave. The comparison causes the turn-on of the output stage at the rising oscillator voltage and the turn-off of the output stage at the falling oscillator voltage. In case of supply-voltage regulation current limitation and short circuit protection for the external transistor has to be provided by an external circuitry. SEN Connecting a sense resistor to the sense input SEN sets the IC automatically in current-mode control (see fig. 1). The minimum input voltage at the sense input is 40mV; the maximum input voltage is 200mV. Voltage peaks higher then 3V are not allowed on the input SEN. The ratio of the overexcitation current to hold current is limited to maximal 5 to 1. The sense input voltage amplified with a gain of 20 is leaded to the PWM comparator K1. The amplifier output voltages are the following: Minimal actual voltage (hold): Maximal actual voltage (overexcitation): 40mV*20 = 800mV 200mV*20 = 4000mV The target voltage on the other input of the comparator will be formed on the inputs INCH (hold) and INCO (overexcitation). In case of an open sense input IC stays in the supply-voltage control. Changing between supply-voltage controlled regulation and current regulation is not allowed. IRCR A resistor on this input sets the reference current for the internal IC biasing. The temperature independent voltage on this pin is 1.5V. An external resistor of RCR = 30k 1% provides a reference current of 50A (1.5V / 30k). The temperature coefficient and the accuracy are directly dependent on the external resistor. Page 6/12 alpha microelectronics gmbh June 1999 INPT The 50-A current source on the input of the thermal shutdown generates a voltage drop over the external resistor RPT. The thermal shutdown circuitry compares this voltage with the voltage of two forward biased diodes (TC = -4mV/C). By varying the value of RPT any desired shutdown temperature is programmable. The thermal protection has a temperature hysteresis of 6C. If the thermal shutdown is active all IC functions are turned off. This state is reported to the output OST. After thermal shutdown releases, all IC functions starts in the same way as the turn-on over the supply voltage. In case of mode 1, mode 2 or mode 4 overexcitation is automatically performed, also in the present of an input signal during temperature shutdown. In case of mode 3 overexcitation has to be external triggered (with a short turn-off-turn-on input sequence) after thermal shutdown releases. Without these retriggering the IC turns on only in the hold mode. The error state in case of mode 3 with a permanent low-level input signal (turn-on) is not readable. If the input INPT is connected to GND, the thermal shutdown is disabled. An open input turns off the IC immediately. The input INPT can also be controlled with a voltage. For the calculation of RPT is valid: RPT [nF] = 22k - 0.076k / K*(TOff - 60C) INST These input is intended for the use of relays with a separate final-position contact. The i1614 automatically starts a single overexcitation in case of a forbidden release of the relay armature (see fig. 3). If the relay armature does not pull until the end of the overexcitation time because of a defect in the winding or other mechanical errors, all functions of the IC are switched off. The error state is signaled with low level ( 1V) on the status output. A renewed start of the IC is only possible after a power-on reset caused by a switch-off / switch-on of the supply voltage. The error state in case of mode 3 with a permanent low-level input signal (turn-on) is not readable. June 1999 alpha microelectronics gmbh Page 7/12 Absolute Maximum Ratings at Tamb = -40C ... +150C Symbol Parameter Min Max Unit -300 100 V VDD Supply Voltage -IBOUT Output Current BOUT -5 5 mA IOVP Output Current OVP, t < 10s 0 40 mA IOUTp Output Current OUT, t < 200s -200 200 mA IOUT Output Current OUT -10 10 mA -IVDDC Output Current VDDC 0 20 mA IIN Input Current IN 0 20 mA VIN Input Voltage IN 45 VDDC V IREF Input Current REF -100 0 A VMODx Input Voltage MODA, MODB 0 5 V VCOSC Input Voltage COSC 0 5 V VCTO Input Voltage CTO 0 5 V VSEN Input Voltage SEN 0 5 V VINxx Input Voltage INPT, INCO, INCH, INST, IRCR 0 5 V CVDDC Block Capacitor CVDDC dependent on VDD, VDD = 15V VDD = 45V 1 0.22 F F RREF Resistor RREF 30.6 kW TCREF Temperature Coefficient RREF 50 ppm Tj Junction Temperature - 175 C Tstg Storage Temperature Range -55 150 C Rthja Thermal Resistance SOP18 95 K/W Page 8/12 29.4 alpha microelectronics gmbh June 1999 Electrical Characteristics Operational Range Symbol Parameter Min Max Unit VDD Supply Voltage 8 45 V VSEN Input Voltage SEN 40 200 mV ICO / ICH Ratio - Overexcitation Current / Hold Current fOSC Oscillator Frequency ( Bootstrap Frequency ) 50 5000 Hz Ta Ambient Temperature Range -40 150 C 5 DC Characteristics at Ta = -40C ... 150C, VDD = 15V, RREF = 30kW; unless otherwise specified Symbol Parameter Conditions Min Max Unit 2 3 mA IDD Current Consumption VDD LON Undervoltage Lockout Turn on 7.5 V VDD LOF Turn off 7.25 V Turn on 4.0 V Turn off 4.0 V VREF LON Power on Reset VREF LOF OUT, BOUT = open, IN = turn ON Typ / VREF / Reference Voltage -IREF = 100A aSEN Gain OVSEN Ta IINCO Input Current INCO VINCO = 3V -50 A IINxx Input Current INCH, INPT VIN = 800mV -50 A Ta OFF Thermal turn OFF RTH = 15kW 140 C Ta ON Thermal turn ON RTH = 15kW 132 C = 25C 4.75 5.0 5.25 19 20 21 V VSENSE = 100mV AC Characteristics at Ta = 25C, VDD = 15V, RREF = 30kW; unless otherwise specified Symbol Parameter Conditions Min Typ Max Unit fOSC Oscillator Frequency COSC = 10nF 740 770 800 Hz tO Overexcitation Time CtO = 33nF 100 110 120 ms June 1999 alpha microelectronics gmbh Page 9/12 Further applications Examples for further applications of the u1614 are: * Current-controlled regulation with overvoltage protection for M1 (see fig. 1) * Supply-voltage controlled regulation with overvoltage protection for M1 (see fig. 2) * Current-controlled regulation with final-position contact function and overvoltage protection for M1 (see fig 3) * Input-controlled PWM (see fig. 4) * Current-controlled regulation with faster discharge of the inductance (see fig. 5) Fig 1: Current-controlled regulation with overvoltage protection for M1 Fig. 2: Supply-voltage controlled regulation with overvoltage protection for M1 Page 10/12 alpha microelectronics gmbh June 1999 Fig. 3: Current-controlled regulation with final-position contact function and overvoltage protection for M1 Fig. 4: Input-controlled PWM regulation Fig. 5: Current-controlled regulation with faster discharge of the inductance June 1999 alpha microelectronics gmbh Page 11/12 Package 18-pin Plastic SOP 10.4 0.2 7.40.2 2.4max. 2.65max. 10 max. 0.420.07 1.27 0.15 0.27 >0.3 10.16 11.570.1 18 17 16 15 14 13 12 11 10 7.400.2 1 2 3 4 5 6 7 8 9 SOP 18 Note It is not given warranty that the declared circuits, devices, facilities, components, assembly groups or treatments included herein are free from legal claims of third parties. The declared data are only a description of product. They are not guaranteed properties as defined by law. The examples are given without obligation and cannot given rise to any liability. Reprinting this data sheet - or parts of it - is only allowed with a license of the publisher. alpha microelectronics gmbh reserves the right to make changes on this specification without notice at any time. alpha microelectronics gmbh Im Technologiepark 1 15236 Frankfurt (Oder) Germany Tel Fax Internet email ++49-335-557 1750 ++49-335-557 1759 http://www.alpha-microelectronics.de alpha@alpha-microelectronics.de 1614DSHa.doc Page 12/12 alpha microelectronics gmbh June 1999