L296P L296HT L296PHT B6633 G0500 MULTIWATT15 PMMUL15V MUL15V - Datasheet Archive

 

L296P HIGH CURRENT SWITCHING REGULATORS . . . . . . . . . . . . . 4 A OUTPUT CURRENT 5.1 V TO 40 V OUTPUT VOLTAGE RANGE 0 TO 100

 

L296 L296P L296P HIGH CURRENT SWITCHING REGULATORS . . . . . . . . . . . . . 4 A OUTPUT CURRENT 5.1 V TO 40 V OUTPUT VOLTAGE RANGE 0 TO 100 % DUTY CYCLE RANGE PRECISE (±2 %) ON-CHIP REFERENCE SWITCHING FREQUENCY UP TO 200 KHz VERY HIGH EFFICIENCY (UP TO 90 %) VERY FEW EXTERNAL COMPONENTS SOFT START RESET OUTPUT EXTERNAL PROGRAMMABLE LIMITING CURRENT (L296P L296P) CONTROL CIRCUIT FOR CROWBAR SCR INPUT FOR REMOTE INHIBIT AND SYNCHRONUS PWM THERMAL SHUTDOWN DESCRIPTION The L296 and L296P L296P are stepdown power switching regulators delivering 4 A at a voltage variable from 5.1 V to 40 V. Features of the devices include soft start, remote inhibit, thermal protection, a reset output for microprocessors and a PWM comparator input for synchronization in multichip configurations. The L296P L296P incudes external programmable limiting current. Multiwatt ® (15 lead) ORDERING NUMBERS : L296 (Vertical) L296HT L296HT (Horizontal) L296P L296P (Vertical) L296PHT L296PHT (Horizontal) The L296 and L296P L296P are mounted in a 15-lead Multiwatt® plastic power package and requires very few external components. Efficient operation at switching frequencies up to 200 KHz allows a reduction in the size and cost of external filter components. A voltage sense input and SCR drive output are provided for optional crowbar overvoltage protection with an external SCR. PIN CONNECTION (top view) April 1993 1/21 L296 - L296P L296P PIN FUNCTIONS N° 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Name CROWBAR INPUT Function Voltage Sense Input for Crowbar Overvoltage Protection. Normally connected to the feedback input thus triggering the SCR when V out exceeds nominal by 20 %. May also monitor the input and a voltage divider can be added to increase the threshold. Connected to ground when SCR not used. OUTPUT Regulator Output SUPPLY VOLTAGE Unrergulated Voltage Input. An internal Regulator Powers the L296s Internal Logic. CURRENT LIMIT A resistor connected between this terminal and ground sets the current limiter threshold. If this terminal is left unconnected the threshold is internally set (see electrical characteristics). SOFT START Soft Start Time Constant. A capacitor is connected between this terminal and ground to define the soft start time constant. This capacitor also determines the average short circuit output current. INHIBIT INPUT TTL ­ Level Remote Inhibit. A logic high level on this input disables the device. SYNC INPUT Multiple L296s are synchronized by connecting the pin 7 inputs together and omitting the oscillator RC network on all but one device. GROUND Common Ground Terminal FREQUENCY A series RC network connected between this terminal and ground determines the COMPENSATION regulation loop gain characteristics. FEEDBACK INPUT The Feedback Terminal on the Regulation Loop. The output is connected directly to this terminal for 5.1V operation ; it is connected via a divider for higher voltages. OSCILLATOR A parallel RC networki connected to this terminal determines the switching frequency. This pin must be connected to pin 7 input when the internal oscillator is used. RESET INPUT Input of the Reset Circuit. The threshold is roughly 5 V. It may be connected to the feedback point or via a divider to the input. RESET DELAY A capacitor connected between this terminal and ground determines the reset signal delay time. RESET OUTPUT Open collector reset signal output. This output is high when the supply is safe. CROWBAR OUTPUT SCR gate drive output of the crowbar circuit. BLOCK DIAGRAM 2/21 L296 - L296P L296P CIRCUIT OPERATION (refer to the block diagram) The L296 and L296P L296P are monolithic stepdown switching regulators providing output voltages from 5.1V to 40V and delivering 4A. The regulation loop consists of a sawtooth oscillator, error amplifier, comparator and the output stage. An error signal is produced by comparing the output voltage with a precise 5.1V on-chip reference (zener zap trimmed to ± 2 %). This error signal is then compared with the sawtooth signal to generate the fixed frequency pulse width modulated pulses which drive the output stage. The gain and frequency stability of the loop can be adjusted by an external RC network connected to pin 9. Closing the loop directly gives an output voltage of 5.1V. Higher voltages are obtained by inserting a voltage divider. Output overcurrents at switch on are prevented by the soft start function. The error amplifier output is initially clamped by the external capacitor Css and allowed to rise, linearly, as this capacitor is charged by a constant current source. Output overload protection is provided in the form of a current limiter. The load current is sensed by an internal metal resistor connected to a comparator. When the load current exceeds a preset threshold this comparator sets a flip flop which disables the output stage and discharges the soft start capacitor. A second comparator resets the flip flop when the voltage across the soft start capacitor has fallen to 0.4V. The output stage is thus re-enabled and the output voltage rises under control of the soft start network. If the overload condition is still present the limiter will trigger again when the threshold current is reached. The average short circuit current is limited to a safe value by the dead time introduced by the soft start network. The reset circuit generates an output signal when the supply voltage exceeds a threshold programmed by an external divider. The reset signal is generated with a delay time programmed by an external capacitor. When the supply falls below the threshold the reset output goes low immediately. The reset output is an open collector. The scrowbar circuit senses the output voltage and the crowbar output can provide a current of 100mA to switch on an external SCR. This SCR is triggered when the output voltage exceeds the nominal by 20%. There is no internal connection between the output and crowbar sense input therefore the crowbar can monitor either the input or the output. A TTL - level inhibit input is provided for applications such as remote on/off control. This input is activated by high logic level and disables circuit operation. After an inhibit the L296 restarts under control of the soft start network. The thermal overload circuit disables circuit operation when the junction temperature reaches about 150 °C and has hysteresis to prevent unstable conditions. Figure 1 : Reset Output Waveforms 3/21 L296 - L296P L296P Figure 2 : Soft Start Waveforms Figure 3 : Current Limiter Waveforms ABSOLUTE MAXIMUM RATINGS Symbol Vi Vi ­ V2 V2 V1, V12 V15 V4, V5, V7, V9, V13 V10, V6 V14 Parameter Value Unit Input Voltage (pin 3) 50 V Input to Output Voltage Difference 50 V ­1 ­7 V V Output DC Voltage Output Peak Voltage at t = 0.1 µsec f = 200KHz Voltage at Pins 1, 12 10 V Voltage at Pin 15 15 V Voltage at Pins 4, 5, 7, 9 and 13 5.5 V Voltage at Pins 10 and 6 7 V Voltage at Pin 14 (I14 1 mA) Vi I9 1 Pin 11 Source Current 20 mA I14 Pin 14 Sink Current (V14 < 5 V) 50 mA Ptot Power Dissipation at Tcase 90 °C 20 W Tj, Tstg 4/21 Pin 9 Sink Current I11 mA Junction and Storage Temperature ­ 40 to 150 °C L296 - L296P L296P THERMAL DATA Symbol Parameter Value Unit Rth j-case Thermal Resistance Junction-case Max. 3 °C/W Rth j-amb Thermal Resistance Junction-ambient Max. 35 °C/W ELECTRICAL CHARACTERISTICS (refer to the test circuits Tj = 25oC, Vi = 35V, unless otherwise specified) Symbol Parameter Test Conditions Min. Typ. Max. Unit Fig. DYNAMIC CHARACTERISTICS (pin 6 to GND unless otherwise specified) Vo Output Voltage Range Vi = 46V, Io = 1A Vi Input Voltage Range Vo = Vref to 36V, Io 3A Vi Input Voltage Range Note (1), Vo = VREF to 36V Io = 4A Vo Line Regulation Load Regulation Internal Reference Voltage (pin 10) Vi = 9V to 46V, Io = 2A V 4 46 V 4 46 V 4 50 mV 4 mV 4 V 4 Vo = Vref Io = 2A to 4A Io = 0.5A to 4A Vref 40 9 Vi =10V to 40V, Vo = Vref, Io = 2A Vo Vref Vref T 15 10 15 5 30 45 5.1 5.2 Average Temperature Coefficient of Reference Voltage Tj = 0°C to 125°C, Io = 2A 0.4 Vd Dropout Voltage Between Pin 2 and Pin 3 Io = 4A Io = 2A 2 1.3 I2L Current Limiting Threshold (pin 2) L296 - Pin 4 Open, Vi = 9V to 40V, Vo = Vref to 36V L296P L296P - Vi = 9V to 40V, Vo = Vref Pin 4 Open RIim = 22k ISH SVR f Input Average Current 3.2 2.1 V V 4 4 4.5 7.5 A 4 A 4 5 2.5 7 4.5 Vi = 46V, Output Short-circuited Efficiency Io = 3 A Vo = Vref Vo = 12V Supply Voltage Ripple Rejection Vi = 2 Vrms, fripple = 100Hz Vo = Vref, Io = 2A 60 100 mA 4 % 4 dB 4 75 85 50 56 85 Switching Frequency mV/°C 100 Vi = 9V to 46V f Tj Temperature Stability of Switching Frequency Tj = 0°C to 125°C fmax Maximum Operating Switching Frequency Vo = Vref, Io = 1A Thermal Shutdown Junction Temperature Note (2) 135 115 4 % 4 kHz ­ °C ­ 200 Tsd 4 % 1 Voltage Stability of Switching Frequency kHz 0.5 f Vi 145 DC CHARACTERISTICS I3Q ­ I2L Note Quiescent Drain Current Output Leakage Current Vi = 46V, V7 = 0V, S1 : B, S2 : B V6 = 0V V6 = 3V Vi = 46V, V6 = 3V, S1 : B, S2 : A, V7 = 0V mA 66 30 85 40 2 mA (1) : Using min. 7 A schottky diode. (2) : Guaranteed by design, not 100 % tested in production. 5/21 L296 - L296P L296P ELECTRICAL CHARACTERISTICS (continued) Symbol Parameter Test Conditions Min. Typ. Max. Unit Fig. SOFT START I5 so Source Current V6 = 0V, V5 = 3V 80 130 150 µA 6b I5 si Sink Current V6 = 3V, V5 = 3V 50 70 120 µA 6b Input Voltage Low Level High Level Vi = 9V to 46V, V7 = 0V, S1 : B, S2 : B V 6a V6L V6H Vi = 9V to 46V, V7 = 0V, S1 : B, S2 : B V6 = 0.8V V6 = 2V µA 6a ­ I6L ­ I6H Input Current with Input Voltage Low Level High Level V 6c V 6c INHIBIT ­ 0.3 2 0.8 5.5 10 3 ERROR AMPLIFIER V9H High Level Output Voltage V10 = 4.7V, I9 = 100µA, S1 : A, S2 : A V9L Low Level Output Voltage V10 = 5.3V, I9 = 100µA, S1 : A, S2 : E I9 si Sink Output Current V10 = 5.3V, S1 : A, S2 : B 100 150 µA 6c Source Output Current V10 = 4.7V, S1 : A, S2 : D 100 150 µA 6c I10 Input Bias Current V10 = 5.2V, S1 : B V10 = 6.4V, S1 : B, L296P L296P µA µA 6c 6c Gv DC Open Loop Gain V9 = 1V to 3V, S1 : A, S2 : C dB 6c µA 6a ­ I9 so 3.5 0.5 2 2 46 10 10 55 OSCILLATOR AND PWM COMPARATOR ­ I7 Input Bias Current of PWM Comparator V7 = 0.5V to 3.5V ­ I11 Oscillator Source Current V11 = 2V, S1 : A, S2 : B 5 5 mA RESET V12 R Rising Threshold Voltage V12 F Falling Threshold Voltage Vi = 9V to 46V, S1 : B, S2 : B V13 D Delay Thershold Voltage V13 H Delay Threshold Voltage Hysteresis V14 S Output Saturation Voltage V12 = 0V to Vref, S1 : B, S2 : B Delay Source Current Delay Sink Current V13 = 3V, S1 : A, S2 : B V12 = 5.3V V12 = 4.7V Output Leakage Current 4.75 Vref -50mV V 6d Vref Vref -150mV -100mV V 6d V 6d mV 6d I14 = 16mA, V12 = 4.7V, S1, S2 : B Input Bias Current Vref Vref -150mV -100mV Vi = 46V, V12 = 5.3V, S1 : B, S2 : A I12 ­ I13 so I13 si I14 4.3 V12 = 5.3V, S1 : A, S2 : B 4.5 4.7 100 0.4 6d 3 µA 6d 110 140 µA mA 100 70 10 V 1 µA 6d 6d CROWBAR V1 Input Threshold Voltage S1 : B V15 Output Saturation Voltage Vi = 9V to 46V, Vi = 5.4V, I15 = 5mA, S1 : A Input Bias Current V1 = 6V, S1 : B Output Source Current Vi = 9V to 46V, V1 = 6.5V, V15 = 2V, S1 : B I1 ­ I15 6/21 5.5 6 6.4 V 6b 0.2 0.4 V 6b 10 70 100 µA 6b mA 6b L296 - L296P L296P Figure 4 : Dynamic Test Circuit C7, C8 : EKR (ROE) L1 : L = 300 µH at 8 A Core type : MAGNETICS 58930 - A2 MPP N° turns : 43 Wire Gauge : 1 mm (18 AWG) COGEMA 946044 (*) Minimum suggested value (10 µF) to avoid oscillations. Ripple consideration leads to typical value of 1000 µF or higher. Figure 5 : PC. Board and Component Layout of the Circuit of Figure 4 (1:1 scale) 7/21 L296 - L296P L296P Figure 6 : DC Test Circuits. Figure 6a. Figure 6b. Figure 6c. 1 - Set V10 FOR V9 = 1 V 2 - Change V10 to obtain V9 = 3 V 3 - GV = DV9 V10 Figure 6d. 8/21 = 2V V10 L296 - L296P L296P Figure 7 : Quienscent Drain Current vs. Supply Voltage (0 % Duty Cycle - see fig. 6a). Figure 8 : Quienscent Drain Current vs. Supply Voltage (100 % Duty Cycle see fig. 6a). Figure 9 : Quiescent Drain Current vs. Junction Temperature (0 % Duty Cycle see fig. 6a). Figure 10 : Quiescent Drain Current vs. Junction Temperature (100 % Duty Cycle see fig. 6a). Figure 11 : Reference Voltage (pin 10) vs. VI (see fig. 4). Figure 12 : Reference Voltage (pin 10) vs. Junction Temperature (see fig. 4). 9/21 L296 - L296P L296P Figure 13 : Open Loop Frequency and Phase Response of Error Amplifier (see fig. 6c). Figure 14 : Switching Frequency vs. Input Voltage (see fig. 4). Figure 15 : Switching Frequency vs. Junction Temperature (see fig. 4). Figure 16 : Switching Frequency vs. R1 (see fig. 4). Figure 17 : Line Transient Response (see fig. 4). Figure 18 : Load Transient Response (see fig. 4). 10/21 L296 - L296P L296P Figure 19 : Supply Voltage Ripple Rejection vs. Frequency (see fig. 4). Figure 20 : Dropout Voltage Between Pin 3 and Pin 2 vs. Current at Pin 2. Figure 21 : Dropout Voltage Between Pin 3 and Pin 2 vs. Junction Temperature. Figure 22 : Power Dissipation Derating Curve. Figure 23 : Power Dissipation (device only) vs. Input Voltage. Figure 24 : Power Dissipation (device only) vs. Input voltage. 11/21 L296 - L296P L296P Figure 25 : Power Dissipation (device only) vs. Output Voltage (see fig. 4). Figure 26 : Power Dissipation (device only) vs. Output Voltage (see fig. 4). Figure 27 : Voltage and Current Waveforms at Pin 2 (see fig. 4). Figure 28 : Efficiency vs. Output Current. Figure 29 : Efficiency vs. Output Voltage. Figure 30 : Efficiency vs. Output Voltage. 12/21 L296 - L296P L296P Figure 31 : Current Limiting Threshold vs. Rpin 4 (L296P L296P only). Figure 32 : Current Limiting Threshold vs. Junction Temperature. Figure 33 : Current Limiting Threshold vs. Supply Voltage. 13/21 L296 - L296P L296P APPLICATION INFORMATION Figure 34 : Typical Application Circuit. (*) Minimum value (10 µF) to avoid oscillations ; ripple consideration leads to typical value of 1000 µF or higher L1 : 58930 - MPP COGEMA 946044 ; GUP 20 COGEMA 946045 SUGGESTED INDUCTOR (L1) Core Type Magnetics 58930 ­ A2MPP Thomson GUP 20 x 16 x 7 Siemens EC 35/17/10 (B6633 B6633& ­ G0500 G0500 ­ X127) VOGT 250 µH Toroidal Coil, Part Number 5730501800 V0 12 V 15 V 18 V 24 V 14/21 No Turns 43 65 40 Wire Gauge 1.0 mm 0.8 mm 2 x 0.8 mm Resistor Values for Standard Output Voltages R8 4.7 K 4.7 K 4.7 K 4.7 K Air Gap ­ 1 mm ­ R7 6.2 K 9.1 K 12 K 18 K L296 - L296P L296P Figure 35 : P.C. Board and Component Layout of the Circuit of fig. 34 (1:1 scale) SELECTION OF COMPONENT VALUES (see fig. 34) Component Recommended Value R1 R2 ­ 100 k Set Input Voltage Threshold for Reset. R3 R4 4.3 k 10 k Sets Switching Frequency Pull-down Resistor R5 R6 15 k Frequency Compensation Collector Load For Reset Output R7 R8 ­ 4.7 k Divider to Set Output Voltage Riim ­ C1 C2 C3 C4 Purpose Allowed Rage Notes Min. Max. ­ Vi min -1 220k R1/R2 5 If output voltage is sensed R1 and R2 may be limited and pin 12 connected to pin 10. 1 k 100k 22k May be omitted and pin 6 grounded if inhibit not used. 10k Omitted if reset function not used. VO 0.05A ­ ­ ­ 1k Sets Current Limit Level 7.5k 10 µF 2.2 µF 2.2 nF 2.2 µF Stability Sets Reset Delay Sets Switching Frequency Soft Start 2.2µF ­ 1 nF 1 µF ­ 3.3nF ­ C5 C6 33 nF 390 pF ­ ­ C7, C8 L1 Q1 100 µF 300 µH Frequency Compensation High Frequency Compensation Output Filter ­ 100µH VO - VREF VREF If Riim is omitted and pin 4 left open the current limit is internally fixed. R7/R8 = ­ D1 Crowbar Protection Recirculation Diode Omitted if reset function not used. Also determines average short circuit current. Not required for 5 V operation. The SCR must be able to withstand the peak discharge current of the output capacitor and the short circuit current of the device. 7A Schottky or 35 ns trr Diode. 15/21 L296 - L296P L296P Figure 36 : A Minimal 5.1 V Fixed Regulator. Very Few Components are Required. Figure 37 : 12 V/10 A Power Supply. 16/21 L296 - L296P L296P Figure 38 : Programmable Power Supply. V o = 5.1 to 15 V I o = 4 A max. (min. load current = 100 mA) ripple 20 mV load regulation (1 A to 4 A) = 10 mV (V o = 5.1 V) line regulation (220 V ± 15 % and to I o = 3 A) = 15 mV (V o = 5.1 V) Figure 39 : Preregulator for Distributed Supplies. (*) L2 and C2 are necessary to reduce the switching frequency spikes. 17/21 L296 - L296P L296P Figure 40 : In Multiple Supplies Several L296s can be Synchronized As Shown. Figure 41 : Voltage Sensing for Remote Load. Figure 42 : A 5.1 V/15 V/24 V Multiple Supply. Note the Synchronization of the Three L296s. 18/21 L296 - L296P L296P Figure 43 : 5.1V/2A Power Supply using External Limiting Current Resistor and Crowbar Protection on the Supply Voltage (L296P L296P only) SOFT-START AND REPETITIVE POWER-ON When the device is repetitively powered-on, the softstart capacitor, CSS, must be discharged rapidly to ensure that each start is "soft". This can be achieved economically using the reset circuit, as shown in Figure 44. In this circuit the divider R1, R2 connected to pin 12 determines the minimum supply voltage, below which the open collector transistor at the pin 14 output discharges CSS. Figure 44 sistor may be added, as shown in Figure 45 ; with this circuit discharge times of a few microseconds may be obtained. Figure 45 HOW TO OBTAIN BOTH RESET AND POWER FAIL Figure 46 illustrates how it is possible to obtain at the same time both the power fail and reset functions simply by adding one diode (D) and one resistor (R). In this case the Reset delay time (pin 13) can only start when the output voltage is VO VREF - 100mV and the voltage accross R2 is higher than 4.5V. With the hysteresis resistor it is possible to fix the input pin 12 hysteresis in order to increase immunity to the 100Hz ripple present on the supply voltage. Moreover, the power fail and reset delay time are automatically locked to the soft-start. Soft-start and delayed reset are thus two sequential functions. The hysteresis resistor should be In the range of aboit 100k and the pull-up resistor of 1 to 2.2k. Figure 46 The approximate discharge times obtained with this circuit are : CSS (µF) tDIS (µs) 2.2 4.7 10 200 300 600 If these times are still too long, an external PNP tran- 19/21 L296 - L296P L296P MULTIWATT15 MULTIWATT15 VERTICAL PACKAGE MECHANICAL DATA Millimeters Typ. Max. 5 2.65 1.6 Min. 0.55 0.75 1.4 17.91 0.019 0.026 0.045 0.692 0.772 1 0.49 0.66 1.14 17.57 19.6 22.1 22 17.65 17.25 10.3 2.65 4.2 4.5 1.9 1.9 3.65 1.27 17.78 17.5 10.7 4.3 5.08 Inches Typ. Max. 0.197 0.104 0.063 0.039 20.2 22.6 22.5 18.1 17.75 10.9 2.9 4.6 5.3 2.6 2.6 3.85 0.870 0.866 0.695 0.679 0.406 0.104 0.165 0.177 0.075 0.075 0.144 0.050 0.700 0.689 0.421 0.169 0.200 0.022 0.030 0.055 0.705 0.795 0.890 0.886 0.713 0.699 0.429 0.114 0.181 0.209 0.102 0.102 0.152 PMMUL15V PMMUL15V.EPS A B C D E F G G1 H1 H2 L L1 L2 L3 L4 L7 M M1 S S1 Dia. 1 Min. MUL15V MUL15V.TBL Dimensions 20/21 L296 - L296P L296P Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of SGS-THOMSON Microelectronics. © 1994 SGS-THOMSON Microelectronics - All Rights Reserved SGS-THOMSON Microelectronics GROUP OF COMPANIES Australia - Brazil - France - Germany - Hong Kong - Italy - Japan - Korea - Malaysia - Malta - Morocco - The Netherlands - Singapore Spain - Sweden - Switzerland - Taiwan - Thaliand - United Kingdom - U.S.A. 21/21