TLE4728G

2-Phase Stepper-Motor Driver TLE 4728 G Bipolar-IC Overview Features • 2 × 0.7 amp. full bridge outputs • Integrated driver, control logic and current control (chopper) • Fast free-wheeling diodes • Max. supply voltage 45 V • Output stages are free of crossover current • Offset-phase turn-ON of output stages • All outputs short-circuit proof • Error-flag for overload, open load, overtemperature • SMD package P-DSO-24-3 Type TLE 4728 G Description TLE 4728 G is a bipolar, monolithic IC for driving bipolar stepper motors, DC motors and other inductive loads that operate by constant current. The control logic and power output stages for two bipolar windings are integrated on a single chip which permits switched current control of motors with 0.7 A per phase at operating voltages up to 16 V. The direction and value of current are programmable for each phase via separate control inputs. A common oscillator generates the timing for the current control and turn-on with phase offset of the two output stages. The two output stages in full-bridge configuration include fast integrated free wheeling diodes and are free of crossover current. The device can be driven directly by a microprocessor in several modes by programming phase direction and current control of each bridge independently. With the two error outputs the TLE 4728 G signals malfunction of the device. Setting the control inputs high resets the error flag and by reactivating the bridges one by one the location of the error can be found. Ordering Code Q67006-A9077 Package P-DSO-24-9 Data Sheet 1 2004-03-01 TLE 4728 G TLE 4728 G Ι 10 Ι 11 Phase 1 OSC GND GND GND GND Q11 R1 + VS Q12 Ι 20 Ι 21 Phase 2 Error 1 GND GND GND GND Q21 R2 Error 2 Q22 1 2 3 4 5 6 7 8 9 10 11 12 24 23 22 21 20 19 18 17 16 15 14 13 IEP01211 Figure 1 Pin Configuration (top view) Data Sheet 2 2004-03-01 TLE 4728 G Pin Definitions and Functions Pin No. 1, 2, 23, 24 Function Digital control inputs IX0, IX1 for the magnitude of the current of the particular phase. Iset = 450 mA with Rsense = 1 Ω IX1 IX0 H H L L 1) Phase Current 0 0.155 × Iset Example of Motor Status No current1) Hold Normal mode Accelerate H L H L Iset 1.55 × Iset “No current” in both bridges inhibits the circuit and current consumption will sink below 3 mA 3 Input phase 1; controls the current through phase winding 1. On H-potential the phase current flows from Q11 to Q12, on L-potential in the reverse direction. Oscillator; works at approx. 25 kHz if this pin is wired to ground across 2.2 nF. Resistor R1 for sensing the current in phase 1. Push-pull outputs Q11, Q12 for phase 1 with integrated free-wheeling diodes. Supply voltage; block to ground, as close as possible to the IC, with a stable electrolytic capacitor of at least 47 µF in parallel with a ceramic capacitor of 100 nF. Error 2 output; signals with “low” the errors: short circuit to ground of one or more outputs or overtemperature. Push-pull outputs Q22, Q21 for phase 2 with integrated free-wheeling diodes. Resistor R2 for sensing the current in phase 2. 5 ... 8, 17 ... 20 Ground; all pins are connected at leadframe internally. 4 10 9, 12 11 14 13, 16 15 Data Sheet 3 2004-03-01 TLE 4728 G Pin Definitions and Functions (cont’d) Pin No. 21 Function Error 1 output; signals with “low” the errors: open load or short circuit to + VS of one or more outputs or short circuit of the load or overtemperature. Input phase 2; controls the current flow through phase winding 2. On H-potential the phase current flows from Q21 to Q22, on L-potential in the reverse direction. 22 Figure 2 Block Diagram Data Sheet 4 2004-03-01 TLE 4728 G Absolute Maximum Ratings Tj = – 40 to 150 °C Parameter Supply voltage Error outputs Output current Ground current Logic inputs Oscillator voltage Symbol Limit Values min. max. 45 45 3 1 – 15 6 5 125 150 125 75 50 V V mA A A V V V °C °C °C – – – – – IXX; Phase 1, 2 – – – Max. 10,000 h – – 0.3 – 0.3 – –1 –2 – 15 – 0.3 – 0.3 – – – 50 – – Unit Remarks R1, R2 input voltage Junction temperature Storage temperature VS VErr IErr IQ IGND VIXX VOSC VRX Tj Tj Tstg Thermal resistances Junction-ambient Rth ja Junction-ambient Rth ja (soldered on a 35 µm thick 20 cm2 PC board copper area) Junction-case Rth jc K/W – K/W – – 15 K/W Measured on pin 5 Note: Stresses above those listed here may cause permanent damage to the device. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Data Sheet 5 2004-03-01 TLE 4728 G Operating Range Parameter Supply voltage Case temperature Output current Logic inputs Error outputs Symbol Limit Values min. max. 16 110 800 6 25 1 V °C mA V V mA – Measured on pin 5 Pdiss = 2 W – IXX; Phase 1, 2 – – 5 – 40 – 800 –5 – 0 Unit Remarks VS TC IQ VIXX VErr IErr Note: In the operating range, the functions given in the circuit description are fulfilled. For details see next four pages. These parameters are not 100% tested in production, but guaranteed by design. Characteristics VS = 6 to 16 V; Tj = – 40 to 130 °C Parameter Symbol Limit Values min. Current Consumption From + VS From + VS typ. max. Unit Test Condition IS IS 0.8 20 1.7 30 2.7 50 mA mA IXX = H IXX = L; IQ1, 2 = 0 A Oscillator Output charging current Charging threshold Discharging threshold Frequency IOSC VOSCL VOSCH fOSC 90 0.8 1.7 18 120 1.3 2.3 24 135 1.9 2.9 30 µA V V kHz – – – COSC = 2.2 nF Data Sheet 6 2004-03-01 TLE 4728 G Characteristics (cont’d) VS = 6 to 16 V; Tj = – 40 to 130 °C Parameter Symbol Limit Values min. Phase Current (VS = 9 … 16 V) Mode “no current” Voltage threshold of current Comparator at Rsense in mode: Hold Setpoint Accelerate typ. max. Unit Test Condition IQ Vch Vcs Vca –2 0 2 mA IX0 = H; IX1 = H 40 410 630 70 450 700 100 510 800 mV mV mV IX0 = L; IX1 = H IX0 = H; IX1 = L IX0 = L; IX1 = L Logic Inputs (IX1; IX0; Phase X) Threshold Hysteresis L-input current L-input current H-input current Error Outputs Saturation voltage Leakage current Thermal Protection Shutdown Prealarm Delta VI VIHy IIL IIL IIH 1.2 – – 10 – 100 –1 1.7 50 –1 – 20 0 2.2 – 1 –5 10 V mV µA µA µA – – VI = 1.2 V VI = 0 V VI = 5 V VErrSat IErrL 50 – 200 – 500 10 mV µA IErr = 1 mA VErr = 25 V Tjsd Tjpa ∆Tj 140 120 10 150 130 20 160 140 30 °C °C K IQ1, 2 = 0 A VErr = L ∆Tj = Tjsd – Tjpa Data Sheet 7 2004-03-01 TLE 4728 G Characteristics (cont’d) VS = 6 to 16 V; Tj = – 40 to 130 °C Parameter Symbol Limit Values min. Power Outputs Diode Transistor Sink Pair (D13, T13; D14, T14; D23, T23; D24, T24) Saturation voltage Saturation voltage Reverse current Forward voltage Forward voltage typ. max. Unit Test Condition VsatI VsatI IRI VFI VFI 0.1 0.2 500 0.6 0.7 0.3 0.5 1000 0.9 1 0.5 0.8 1500 1.2 1.3 V V µA V V IQ = – 0.45 A IQ = – 0.7 A VS = VQ = 40 V IQ = 0.45 A IQ = 0.7 A Diode Transistor Source Pair (T11, D11; T12, D12; T21, D21; T22, D22) Saturation voltage Saturation voltage Saturation voltage Saturation voltage Reverse current Forward voltage Forward voltage Diode leakage current VsatuC VsatuD VsatuC VsatuD IRu VFu VFu ISL 0.6 0.1 0.7 0.2 400 0.7 0.8 0 1 0.3 1.2 0.5 800 1 1.1 3 1.2 0.6 1.5 0.8 1200 1.3 1.4 10 V V V V µA V V mA IQ = 0.45 A; charge IQ = 0.45 A; discharge IQ = 0.7 A; charge IQ = 0.7 A; discharge VS = 40 V, VQ = 0 V IQ = – 0.45 A IQ = – 0.7 A IF = – 0.7 A Error Output Timing Time Phase X to IXX Time IXX to Phase X Delay Phase X to Error 2 Delay Phase X to Error 1 Delay IXX to Error 2 Reset delay after Phase X Reset delay after IXX tPI tIP tPEsc tPEol tIEsc tRP tRI – – – – – – – 5 12 45 15 30 3 1 15 – 80 30 60 10 5 µs µs µs µs µs µs µs – – – – – – – Data Sheet 8 2004-03-01 TLE 4728 G Diagrams Timing between IXX and Phase X to prevent setting the error flag Operating conditions: + VS = 14 V, Tj = 25 °C, Ierr = 1 mA, load = 3.3 mH, 1 Ω a) If tPI < typ. 5 µs, an error “open load” will be set. Ι XX Phase X t PI IET01888 Figure 3 b) If tIP < typ. 12 µs, an error “open load” will be set. Ι XX Phase X t IP IET01889 Figure 4 Data Sheet 9 2004-03-01 TLE 4728 G This time strongly depends on + VS and inductivity of the load, see diagram below. Time tIP versus Load Inductivity Propagation Delay of the Error Flag Operating conditions: + VS = 14 V, Tj = 25 °C, Ierr = 1 mA, load = 3.3 mH, 1 Ω a) IXX = L, error condition: short circuit to GND. Phase X Error 2 t PEsc IET01883 typ. tPEsc: 45 µs Figure 5 Data Sheet 10 2004-03-01 TLE 4728 G b) IXX = L, error condition: open load (equivalent: short circuit to + VS). Phase X Error 1 t PEol IET01884 typ. tPEol: 15 µs Figure 6 c) Phase X = H or L, const.; error condition: short circuit to GND. Ι XX Error 2 t IEsc IET01885 typ. tIEsc: 30 µs tIEsc is also measured under the condition: begin of short circuit to GND till error flag set. Figure 7 Data Sheet 11 2004-03-01 TLE 4728 G d) IXX = L, reset of error flag when error condition is not true. Phase x Error X t RP IET01886 typ. tRP: 3 µs Figure 8 e) Phase X = H or L, const.; reset of error flag when error condition is not true. Ι XX Error X t RI IET01887 typ. tRI: 1 µs Figure 9 Data Sheet 12 2004-03-01 TLE 4728 G Quiescent Current IS versus Supply Voltage VS; bridges not chopping; Tj = 25 °C Quiesc. Current IS versus Junct. Temp. Tj; bridges not chopping, VS = 14 V 60 IED01828 60 IED01827 ΙS mA 50 Ι QX = 0.70 A ΙS mA 50 Ι QX = 0.70 A 0.50 A 40 0.45 A 0.07 A 40 0.07 A 30 30 20 20 10 10 0 5 10 15 V VS Oscillator Frequency fOsc versus Junction Temperature Tj 30 kHz f Osc 25 IED01829 20 0 -50 0 50 C Tj 150 Output Current IQX versus Junction Temperature Tj 800 mA 700 600 500 IED01830 Ι QX Ι X1 = H, Ι X0 = H VS = 14 V C OSC = 2.2 nF 20 400 300 200 100 Ι X1 = H, Ι X0 = L V S = 14 V R X = 1Ω 15 -50 0 50 100 C 150 Tj 0 -50 0 50 100 C 150 Tj Data Sheet 13 2004-03-01 TLE 4728 G Output Saturation Voltages Vsat versus Output Current IQ 2.0 V sat V 1.5 V S = 14 V T j = 25 C IED01831 Forward Current IF of Free-Wheeling Diodes versus Forward Voltages VF 1.0 IED01218 ΙF A 0.8 V Fl V Fu 1.0 V satuC 0.6 T j = 25 ˚C 0.4 0.5 V satl V satuD 0.2 0 0 0 0.2 0.4 0.6 A 0.8 0 0.5 1.0 V VF 1.5 ΙQ Typical Power Dissipation Ptot versus Output Current IQ (non stepping) 4 P tot W 3 L phase x = 10 mH R phase x = 2 Ω C OSC TC = 2.2 nF = 25 C IED01832 Permissible Power Dissipation Ptot versus Case Temp. TC (measured at pin 5) 16 P tot W 12 10 8 IED01833 both phases active 2 V S = 14 V 1 Tjmax = 150 C 120 C 6 4 2 0 0 0.2 0.4 0.6 A 0.8 0 -25 0 25 75 ΙQ 125 C 175 TC Data Sheet 14 2004-03-01 TLE 4728 G Input Characteristics of IXX, Phase X IED01834 Output Leakage Current IED01835 i Ι xx 40 µA 20 0 -20 -40 Tj = -60 -80 40 C 25 C 150 C 1.2 Ι xx ΙR mA 0.8 Phase X V S = 40 V 0.4 V S = 16 V 0 -0.4 -100 -120 -6 -0.8 -4 -2 0 2 4V6 V Ι xx 0 10 20 30 V VQ 40 Data Sheet 15 2004-03-01 TLE 4728 G +12 V 100 nF 11 VS Q11 Q12 9 12 16 13 100 µF 1 2 3 Microcontroller Ι 10 Ι 11 Phase 1 21 Error 1 14 Error 2 24 23 22 Ι 20 Ι 21 Phase 2 OSC 4 2.2 nF TLE 4728G Q21 Q22 M Stepper Motor 15 R2 1Ω 10 R1 1Ω GND 5, 6, 7, 8, 17, 18, 19, 20 IES01223 Figure 10 Application Circuit 100 µF 100 nF VS ΙS +V S V satu V Fu ΙΙ VΙ Ι XX, Phase X TLE 4728 G Error X Output Ι Rl ΙQ Ι Ru V satl Ι Err V Err V OSC Osc GND R sense V Fl Ι OSC 2.2 nF Ι SL Ι GND VC Ι Rsense 1Ω IES01836 Figure 11 Test Circuit Data Sheet 16 2004-03-01 TLE 4728 G Accelerate Mode Normal Mode Ι 10 Ι 11 Phase 1 H L H L H L i acc i set t t t Ι Q1 i set i acc i acc i set t Ι Q2 i set i acc Phase 2 H L H L H L t t t Ι 20 Ι 21 t IED01776 Figure 12 Full Step Operation Data Sheet 17 2004-03-01 TLE 4728 G Accelerate Mode Normal Mode Ι 10 Ι 11 H L H L H L i acc i set t t Phase 1 t Ι Q1 - i set - i acc i acc i set t Ι Q2 - i set - i acc Phase 2 H L H L H L t t Ι 20 Ι 21 t t IED01777 Figure 13 Half Step Operation Data Sheet 18 2004-03-01 TLE 4728 G V Osc V Osc V Osc Ι Rsense 1 0 t Ι Rsense 2 0 V Q12 +VS V satl V ca 0 V Q11 +VS V Q22 +VS V satu D V satu C t t V FU t 0 V Q21 +VS t Ι Q1 i acc Ι Q2 i acc t t Operating conditions: VS = 14 V L phase x = 10 mH R phase x = 4 Ω Phase = H Ι XX = L IED01778 Figure 14 Current Control in Chop-Mode Data Sheet 19 2004-03-01 TLE 4728 G V Osc 2.3 V 1.3 V 0V Phase 1 H L Oscillator High Imped. Phase change-over t t Ι Rsense 1 0 t V Q11 + VS High Impedance t V Q12 + VS High Impedance t Ι Phase 1 T1 Ι set fast current decay slow current decay t - Ι set slow current decay IED01779 Operating conditions: VS = 14 V L phase 1 = 1 mH R phase 1 = 4 Ω Ι 11 = H for t < T 1 Ι 11 = L for t > T 1 Ι 10 = Ι 2X = H Figure 15 Phase Reversal and Inhibit Data Sheet 20 2004-03-01 TLE 4728 G Calculation of Power Dissipation The total power dissipation Ptot is made up of saturation losses Psat (transistor saturation voltage and diode forward voltages), quiescent losses Pq (quiescent current times supply voltage) and switching losses Ps (turn-ON / turn-OFF operations). The following equations give the power dissipation for chopper operation without phase reversal. This is the worst case, because full current flows for the entire time and switching losses occur in addition. Ptot = 2 × Psat + Pq + 2 × Ps where Psat ≅ IN { VsatI × d + VFu (1 – d ) + VsatuC × d + VsatuD ( 1 – d ) } Pq = Iq × VS V S  i D × t DON ( i D + i R ) × t ON I N  P q ≅ ------  --------------------- + ---------------------------------- + ---- ( t DOFF + t OFF )  2 2 4 T  IN Iq iD iR tp tON tOFF tDON tDOFF T d Vsatl VsatuC VsatuD VFu VS = nominal current (mean value) = quiescent current = reverse current during turn-on delay = peak reverse current = conducting time of chopper transistor = turn-ON time = turn-OFF time = turn-ON delay = turn-OFF delay = cycle duration = duty cycle tp / T = saturation voltage of sink transistor (TX3, TX4) = saturation voltage of source transistor (TX1, TX2) during charge cycle = saturation voltage of source transistor (TX1, TX2) during discharge cycle = forward voltage of free-wheeling diode (DX1, DX2) = supply voltage Data Sheet 21 2004-03-01 TLE 4728 G +VS Tx2 Tx1 Dx1 L Dx2 Tx4 Tx3 Dx3 Dx4 VC R sense IET01209 Figure 16 Voltage and Current at Chopper Transistor Turn-ON iD iR Turn-OFF ΙN VS + VFu VS + VFu Vsatl t D ON t ON tp t D OFF t OFF t IET01210 Figure 17 Voltage and Current on Chopper Transistor Data Sheet 22 2004-03-01 TLE 4728 G Application Hints The TLE 4728 G is intended to drive both phases of a stepper motor. Special care has been taken to provide high efficiency, robustness and to minimize external components. Power Supply The TLE 4728 G will work with supply voltages ranging from 5 V to 16 V at pin VS. Surges exceeding 16 V at VS wont harm the circuit up to 45 V, but whole function is not guaranteed. As soon as the voltage drops below approximately 16 V the TLE 4728 G works promptly again. As the circuit operates with chopper regulation of the current, interference generation problems can arise in some applications. Therefore the power supply should be decoupled by a 0.1 µF ceramic capacitor located near the package. Unstabilized supplies may even afford higher capacities. Current Sensing The current in the windings of the stepper motor is sensed by the voltage drop across Rsense. Depending on the selected current internal comparators will turn off the sink transistor as soon as the voltage drop reaches certain thresholds (typical 0 V, 0.07 V, 0.45 V and 0.7 V). These thresholds are not affected by variations of VS. Consequently unstabilized supplies will not affect the performance of the regulation. For precise current level it must be considered, that internal bounding wire (typ. 60 mΩ) is a part of Rsense. Due to chopper control fast current rises (up to 10 A/µs) will occur at the sensing resistors. To prevent malfunction of the current sensing mechanism Rsense should be pure ohmic. The resistors should be wired to GND as directly as possible. Capacitive loads such as long cables (with high wire to wire capacity) to the motor should be avoided for the same reason. Synchronizing Several Choppers In some applications synchrone chopping of several stepper motor drivers may be desirable to reduce acoustic interference. This can be done by forcing the oscillator of the TLE 4728 G by a pulse generator overdriving the oscillator loading currents (approximately ± 120 µA). In these applications low level should be between 0 V and 0.8 V while high level should between 3 V and 5 V. Optimizing Noise Immunity Unused inputs should always be wired to proper voltage levels in order to obtain highest possible noise immunity. To prevent crossconduction of the output stages the TLE 4728 G uses a special break before make timing of the power transistors. This timing circuit can be triggered by short glitches (some hundred nanoseconds) at the phase inputs causing the output stage to become high resistive during some microseconds. This will lead to a fast current decay Data Sheet 23 2004-03-01 TLE 4728 G during that time. To achieve maximum current accuracy such glitches at the phase inputs should be avoided by proper control signals. To lower EMI a ceramic capacitor of max. 3 nF is advisable from each output to GND. Thermal Shut Down To protect the circuit against thermal destruction, thermal shut down has been implemented. Error Monitoring The error outputs signal corresponding to the logic table the errors described below. Logic Table Kind of Error Error 1 a) No error b) Short circuit to GND c) Open load 1) d) b) and c) simultaneously e) Temperature pre-alarm 1) Error Output Error 2 H L H L L H H L H L Also possible: short circuit to + VS or short circuit of the load. Overtemperature is implemented as pre-alarm; it appears approximately 20 K before thermal shut down. To detect an open load, the recirculation of the inductive load is watched. If there is no recirculation after a phase change-over, an internal error flipflop is set. Because in most kinds of short circuits there won’t flow any current through the motor, there will be no recirculation after a phase change-over, and the error flipflop for open load will be set, too. Additionally an open load error is signaled after a phase change-over during hold mode. Only in the case of a short circuit to GND, the most probably kind of a short circuit in automotive applications, the malfunction is signaled dominant (see d) in logic table) by a separate error flag. Simultaneously the output current is disabled after 30 µs to prevent disturbances. A phase change-over or putting both current control inputs of the affected bridge on high potential resets the error flipflop. Being a separate flipflop for every bridge, the error can be located in easy way. Data Sheet 24 2004-03-01 TLE 4728 G Package Outlines P-DSO-24-9 (Plastic Dual Small Outline Package) 2.65 MAX. 0.35 x 45˚ +0.0 9 0.2 -0.1 2.45 -0.2 1.27 0.35 +0.15 2) 24 0.4 +0.8 0.1 0.2 24x 13 10.3 ±0.3 1 15.6 -0.4 1) 12 Index Marking 1) 2) Does not include plastic or metal protrusion of 0.15 max. per side Lead width can be 0.61 max. in dambar area Sorts of Packing Package outlines for tubes, trays etc. are contained in our Data Book “Package Information”. SMD = Surface Mounted Device 0.23 Dimensions in mm Data Sheet 25 8˚ MAX. 7.6 -0.2 1) 2004-03-01