Preliminary Data Sheet u1624 Coil Driver IC Description Features The u1624 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 chip overtemperature protection is adjusted from 80 to 150C with an external resistor. Chip overtemperature, undervoltage errors and relay status are indicated on a status output. q q q q q q q q q q q q q Voltage supply 18 to 400VDC 5-V and 12-V reference voltage output Quiescent current 2 mA Output current up to 200mA 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 Undervoltage lockout and power-on reset Protection against EMC Adjustable chip overtemperature protection Temperature range -25C to +85C Package SOP 18 u1624ET Die u1624EX Applications q Current controlled driver for coils q PWM driver for relays Coil driver using u1624 Typical Application VDD Input 14 Mode A 6 Mode B 7 680n CTO 8 18K RCH 13 75K RCO 3 30K RREF 11 15K RPT 10 5 IN VDD MODA VDDC MODB u 17 RSEXT 2 CVDDC 1624 OST CTO OUT1 INCH OUT2 INCO SEN IRCR OSC INPT GND INST VREF 4 L D 220n 15 16 1 12 10n COSC RSEN 18 9 100n CVREF June 1999 alpha microelectronics gmbh Page 1/12 Page 2/12 alpha microelectronics gmbh RCH RCO INCH 13 3 MODB 7 Mode B 50 500K 50 11 30k RREF IRCR Internal Current 10 RPT 6 5 M2 S1 DZ3 200k RV M3 R S 1.5 CCO 8 CTO Mode-Logic 9V tOE- Trigger and Logic Error-Logic INPT Thermal Shutdown 50 500K 500K vU=20 500K Turn on / off Logic COSC 12 M4 K2 COSC 2.5V 3V VDDC 4 3 50 Frequency Control 14V K1 Oscillator S3 VDD 17 1624 i INCO MODA 6 IN INST Mode A Input 14 Relay Status Input 5 2 CVDDC 4 3 R S Q Latch Divider 1:4 Logic Undervoltage Lockout RSEXT 9 4 3 S4 VREF CREF S5 2 Status Reference Regulator 2 1 S6 Driver DZ2 16V 18 GND SEN OUT2 OUT1 OST 1 16 15 4 D RSEN Status Output VDD Functional Block Diagram S2 June 1999 Pin Definition Pin Symbol Designation 1 SEN Current Sense Input 2 VDDC Block Capacitor 3 INCO Resistor for Overexcitation Current 4 OST Output for Status 5 INST Input for Relay Status 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 Reference Current 12 OSC Capacitor for Oscillator Frequency 13 INCH Resistor for Hold Current 14 IN Input 15 OUT1 Output 1 16 OUT2 Output 2 17 VDD Supply Voltage 18 GND GND The location of pins can be changed during the development of the layout. General function and description The i1624 serves for the low loss control of electrical magnetic actuators like relays or magnets and similar kinds of coils. It is especially suitable for the 240-V mains. The i1624 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 internal low-side switch 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 switch 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 /1624 has various safety functions and diagnostic functions such as overvoltage protection, undervoltage lockout, detection of broken wire or short circuit, and a status output. June 1999 alpha microelectronics gmbh Page 3/12 PIN function and description VDD The u1624 is designed for a supply voltage range of VDD = 18 ... 400V. The IC is not protected against reversed polarity of the supply voltage. The internal power supply is 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. For the calculation of RVDD is valid: RVDD = (VDD-150V) / 75mA VDDC The internal preregulated voltage of about 12V is connected to the Pin VDDC and must be bypassed with a capacitor. The voltage on VDDC supplies power to the gate driver of the switch transistor and the internal 5-V reference. Undervoltage detection is performed on VDDC. If the VDDC becomes higher than 6.9V the IC will be enabled (with RVDD = 0 is VDD 9.5V). If the VDDC voltage is lower than 6.7V all functions of the IC are disabled, the output stage is turned off, and the status output indicates low level (with RVDD = 0 is VDD = 8.7V). The VDDC pin can provide an additional current up to 1mA to an external load. In that case the IC power dissipation at higher supply voltages has be taken into consideration. VREF The internal 5-V reference voltage is supplied from VDDC and has to be decoupled with a capacitor of 100nF. It has a high SVR based on the preregulator. The 5-V reference supplies 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. In that case the power dissipation at higher supply voltages has be taken into consideration. The output signals of the undervoltage detector and the power-on-reset circuitry are logically AND connected. OUT1 The maximum drain current of the internal switch transistor (N-ch. MOSFET) is 200mA. The maximum drain voltage is 450V. Negative drain voltages are not allowed. OUT2 The maximum source current of the internal transistor is 200mA. The maximum source voltage is 1V. Negative source voltages are not allowed. 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 The high-impedance 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. It is recommended to limit the maximum input voltage to the value of the VDDC. 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. According to the four input modes (programmed at MODA, MODB) are the following variants for the input control possible: Page 4/12 alpha microelectronics gmbh June 1999 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 can be (1 ... 2) *TPOSC. The functions current-mode control, voltage-mode control, overexcitation, 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 input sequence. The power supply voltage has to exist before the turnon 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 i1620 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] 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. June 1999 alpha microelectronics gmbh Page 5/12 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 internal switching transistor at the rising oscillator voltage and the turn-off of the transistor at the falling oscillator voltage. 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. 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 or mode 2 overexcitation is automatically performed, also in the present of an input signal during temperature shutdown. In case of mode 3 or mode 4 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. 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) Page 6/12 alpha microelectronics gmbh June 1999 INST These input is intended for the use of relays with a separate final-position contact. The i1620 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. OST If there is an error event (undervoltage, overtemperature, final position contact, etc.), the status output shows low level, otherwise it has high level (VREF). June 1999 alpha microelectronics gmbh Page 7/12 Absolute Maximum Ratings at Tamb = -25C ... +85C Symbol Parameter Min Max Unit VDD Supply Voltage 0 450 V IOVP Output Current OVP, t < 10s 0 40 mA IOUTp Output Current OUT, t < 200s 0 1000 mA IOUT Output Current OUT 0 200 mA -IVDDC Output Current VDDC 0 20 mA IIN Input Current IN 0 20 mA VIN Input Voltage IN -12 VDDC V IREF Input Current REF -100 0 A VMODx Input Voltage MODA, MODB 0 5 V VCOSC Input Voltage OSC 0 5 V VCTO Input Voltage CTO 0 5 V VSEN Input Voltage SEN 0 5 V VOST Output Voltage OST 0 5 V IOST Output Current OST 0 2 mA VINxx Input Voltage INPT, INCO, INCH, INST, IRCR 0 5 V CVDDC Capacity of CVDDC 1 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 18 400 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 -25 +85 C 5 DC Characteristics at Ta = -25C ... 85C, VDD = 400V, RREF = 30kW; unless otherwise specified Symbol Parameter Conditions Min Typ Max Unit 3 mA IDD Current Consumption OUT IN = open, = turn ON 2 VOUT Output current Ta = 25C, IOUT = 200mA 5 VV VDD LON Undervoltage Lockout Turn on 15 V VDD LOF Turn off 13 V Turn on 4.0 V Turn off 4.0 V VREF LON Power on Reset VREF LOF / VREF / Reference Voltage -IREF = 100A aSEN Gain OVSEN Ta = 25C 4.75 5.0 5.25 19 20 21 V VSENSE = 100 mV 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 AC Characteristics at Ta = 25C, VDD = 400V, 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 100 110 120 ms June 1999 = 33nF alpha microelectronics gmbh Page 9/12 Further applications Examples for further applications of the u1624 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) 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 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 1624DSHc.doc Page 12/12 alpha microelectronics gmbh June 1999