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L4964
HIGH CURRENT SWITCHING REGULATOR
.4AOUTPUTCURRENT .5. .0TO100%DUTYCYCLERANGE .PRECI .SWI .VERYHI .VERYFEWEXTERNALCOMPONENTS .SOFTSTART .RESETOUTPUT .CURRENTLI .I .THERMALSHUTDOWN
DESCRIPTION
1 V TO 28 V OUTPUT VOLTAGE RANGE SE ( 3 %) ON-CHIP REFERENCE TCHING FREQUENCY UP TO 120 KHz GH EFFICIENCY (UP TO 90 %)
MITING NPUT FOR REMOTE INHIBIT AND SYNCHRONUS PWM
MUL TIW AT T15 Vertical (Plastic Package) ORDERING NUMBER : L4964
The L4964 is a stepdown power switching regulator delivering 4A at a voltage variable from 5.1V to 28V. Features of the device include overload protection, soft start, remote inhibit, thermal protection, a reset output for microprocessors and a PWM comparator input for synchronization in multichip configurations. The L4964 is mounted in a 15-lead Multiwatt(R) plastic power package and requires very few external components. Efficient operation at switching frequencies up to 120kHz allows a reductionin the size and cost of external filter components. PIN CONNECTION (top view)
MULTIWATT15 Horizo ntal (Plastic Package) ORDERING NUMBER : L4964HT
Pins 1, 4, 15 must not be connected. Leave open circuit.
April 1993
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L4964
PIN FUNCTIONS
N 1 2 3 4 5 Name N.C. Output Supply Voltage N.C. Soft Start Regulator Output. Unregulated Voltage Input. An internal regulator powers the L4964's internal logic. Must not be connected. Leave open circuit. 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. TTL - Level Remote Inhibit. A logic high level on this input disables the L4964. Multiple L4964's are synchronized by connecting the pin 7 inputs together and omitting the oscillator RC network on all but one device. Common Ground Terminal. A series RC network connected between this terminal and ground determines the regulation loop gain characteristics. The Feedback Terminal of the Regulation Loop. The output is connected directly to this terminal for 5.1 V operation ; it is connected via a divider for higher voltages. A parallel RC network connected to this terminal determines the switching frequency. The pin must be connected to pin 7 input when the internal oscillator is used. Input of the Reset Circuit. The threshold is roughly 5 V. It may be connected to the beedback point or via a divider to the input. A capacitor connected between this terminal and ground determines the reset signal delay time. Open Collector Reset Signal Output. This output is high when the supply is safe. Must not be connected. Leave open circuit. Function Must not be connected. Leave open circuit.
6 7 8 9 10 11 12 13 14 15
Inhibit Input Sync Input Ground Frequency Compensation Feedback Input Oscillator Reset Input Reset Delay Reset Output N.C.
BLOCK DIAGRAM
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L4964
CIRCUIT OPERATION (refer to the block diagram) The L4964 is a monolithic stepdown switching regulator providing output voltages from 5.1 V to 28 V and delivering 4A. The regulationloop consists of asawtooth oscillator, error amplifier, comparator and the output stage. An error signal is produced by comparing the output voltage with a precise 5.1 V on-chip reference (zener zap trimmed to 3 %). 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 ajusted by an external RC network connected to pin 9. Closing the loop directly gives an output voltage of 5.1 V. 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 externalcapacitor Css andallowed 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. Figure 1 : Reset Output Waveforms A second comparator resets the flip flop when the voltage across the soft start capacitor has fallen to 0.4 V. The output stage is thus re-enable and the outputvoltage rises undercontro of the soft startnetwork. If the overload condition is still present the limiter will trigger again when the thershold 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. A TTL - level input is provided for applications such as remote on/off control. This input is activated by high level and disables circuit operation.After an inhibit the L4964restarts under control of the soft start network. The thermal overload circuit disables circuit operation when the junction temperature reaches about 150 and has hysteresis to prevent unstable conditions.
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L4964
Figure 2 : Soft Start Waveforms
Figure 3 : Current Limiter Waveforms
ABSOLUTE MAXIMUM RATINGS
Symbol Vi Vi - V2 V2 V12 V5, V7, V9 V10, V6, V13 V14 I9 I11 I14 Ptot Tj, Tstg Parameter Input Voltage (pin 3) Input to Output Voltage Difference Output DC Voltage Output Peak Voltage at t = 0.1 sec f = 100 kHz Voltage at Pin 12 Voltage at Pins 5, 7 and 9 Voltage at Pins 10, 6 and 13 Voltage at Pin 14 (I14 1 mA) Pin 9 Sink Current Pin 11 Source Current Pin 14 Sink Current (V 14 < 5 V) Power Dissipation at T case 90 C Junction and Storage Temperature Value 36 38 -1 -7 10 5.5 7 Vi 1 20 50 20 - 40 to 150 Unit V V V V V V V mA mA mA W C
THERMAL DATA
Symbol Rth j-case Rth j-amb 4/13 Parameter Thermal Resistance Junction-case Thermal Resistance Junction-ambient Max. Max. Value 3 35 Unit C/W C/W
L4964
ELECTRICAL CHARACTERISTICS (refer to the test circuits T j = 25oC, Vi = 25V, unless otherwise specified)
Symbol Vo Vi Vo Vo Vref Vref T Vd Iom I2L ISH SVR f f Vi f Tj fmax Tsd Parameter Output Voltage Range Input Voltage Range Line Regulation Load Regulation Test Conditions Min. Typ. Max. 28 36 70 30 50 5.25 Unit V V mV mV mV V mV/C V V A A mA % % dB kHz % % kHz 145 C Fig. 4 4 4 4 4 4 DYNAMIC CHARACTERISTICS (pin 6 to GND unless otherwise specified) Vi = 36V, Io = 1A Vref Vo = Vref to 28V, Io = 3A 9 Vi = 10V to 30V, Vo = Vref, Io = 2A Io = 1A to 2A Io = 0.5A to 3A, Vo = Vref Internal Reference Voltage (Pin 10) Vi = 9V to 36V, Io = 2A 4.95 Average Temperature Coefficient Tj = 0C to 125C, Io = 2A of Reference Voltage Dropout Voltage between Pin 2 and Pin 3 Maximum Operating Load Current Current Limiting Threshold (Pin 2) Input Average Current Efficiency Supply Voltage Ripple Rejection Switching Frequency Voltage Stability of Switching Frequency Temperature Stability of Switching Frequency Maximum Operating Switching Frequency Thermal Shutdown Junction Temperature Quiescent Drain Current Io = 3A Io = 2A VI = 9V to 36V, Vo = Vref to 28V Vi = 9V to 36V, Vo = Vref to 28V Vi = 36V, Output Short-circuited Io = 3A Vo = Vref Vo = 12V VI = 2Vrms, fripple = 100Hz Vo = Vref, Io = 2A Vi = 9V to 36V Tj = 0C to 125C Vo = Vref, Io = 1A 120 135
15 10 15 5.1 0.4 2 1.5
3.2 2.4 8 140
4 4.5 80 75 85 56 50 0.5 1
46 40
- 60
4 4 4 4 4 4 4 4 4 4 4 - -
DC CHARACTERISTICS I3Q -I2L Vi = 36V, V7 = 0V, S1 : B, S2 : B V6 = 0V V6 = 3V Vi = 36V, V6 = 3 V, V7 = 0V S1 : B, S2 : A V6 = 0V, V5 = 3V V6 = 3V, V5 = 3V Vi = 9V to 36V, V7 = 0V S1 : B, S2 : B Vi = 9V to 36V, V7 = 0V S1 : B, S2 : B V6 = 0.8V V6 = 2V V10 = 4.7V, S2 : A V10 = 5.3V, S2 : E V10 = 5.3V, V10 = 4.7V, I9 = 100A, S1 : A, I9 = 100A, S1 : A, S1 : A, S2 : B S1 : A, S2 : D 100 100 150 150 3.4 0.6 80 40 - 0.3 2 mA 66 30 100 50 2 6a
Output Leakage Current
mA
6a
SOFT START I5so I5si INHIBIT V6L V6H - I6L -I6H V9H V9L I9 si -I9 so Low Input Voltage High Input Voltage Input Current with Input Voltage Low Level High Level High Level Output Voltage Low Level Output Voltage Sink Output Current Source Output Current 0.8 5.5 V V A 6a 6a 6a Source Current Sink Current 130 70 180 140 A A 6b 6b
20 10 V V A A 6c 6c 6c 6c 5/13
ERROR AMPLIFIER
L4964
ELECTRICAL CHARACTERISTICS (continued) (refer to the test circuits T j = 25oC, Vi = 25V, unless otherwise specified)
Symbol I10 Gv -I7 -I11 RESET V12R V12F V13D V13H V14S I12 -I13 so I13 si I14 Rising Threshold Voltage Falling Threshold Voltage Delay Threshold Voltage Delay Threshold Voltage Hysteresis Output Saturation Volt. Input Bias Current Delay Source Current Delay Sink Current Output Leakage Current Vi = 9 V to 36 V, S1 : B, S2 : B Vref Vref Vref - 150mV - 100mV - 50mV Vref 4.75 Vref - 150mV - 100mV 4.3 4.5 4.7 100 0.4 10 150 V V V mV V A A mA A 6d 6d 6d 6d 6d 6d 6d Parameter Input Bias Current DC Open Loop Gain Test Conditions V10 = 5.2V, S1 : B V9 = 1V to 3V, S1 : A, S2 : C Min. Typ. 2 55 Max. 20 Unit Fig. A dB A mA 6c 6c 6a 6a ERROR AMPLIFIER (continued) 40
OSCILLATOR AND PWM COMPARATOR Input Bias Current of V7 = 0.5V to 3.5V PWM Comparator Oscillator Source Current V11 = 2V, S1 : A, S2 : B 10 4 -
V12 = 5.3 V, S1 : A, S2 : B I14 = 5mA, V12 = 4.7V - S1, S2 : B V12 = 0V to Vref, S1 : B, S2 : B V13 = 3V, S1 : A, S2 : B V12 = 5.3V V12 = 4.7V Vi = 36V, V12 = 5.3V, S1 : B, S2 : A
1 60 8 110 100
6d
Figure 4 : Dynamic Test Circuit
C7, C8 : EKR (ROE) L1 : L = 300 H at 8 A R = 500 m
Core type : MAGNETICS 58930 - A2 MPP N turns : 43 Wire Gauge : 1 mm (18 AWG)
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L4964
Figure 5 : PC. Board and Component Layout of the Circuit of Fig. 4 (1:1 scale)
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L4964
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 = 2V V10
Figure 6d.
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L4964
Figure 7 : Switching Frequency vs. R1 (see fig. 4). Figure 8 : Open Loop Frequency and Phase Response of Error Amplifier (see fig. 6c).
Figure 9 : Reference Voltage (pin 10) vs. Junction Temperature (see fig. 4).
Figure 10 : Power Dissipation (L4964 only) vs. Input Voltage.
Figure 11 : Efficiency vs. Output Voltage.
Figure 12 : Power Dissipation Derrating Curve.
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L4964
APPLICATION INFORMATION CHOOSING THE INDUCTOR AND CAPACITOR The input and output capacitors of the L4964 must have a low ESR and low inductance at high current ripple. Preferably, the inductor should be a toroidal type or wound on a Moly-Permalloy nucleus.Saturation must not occur at current levels below 1.5 times the Figure 13 : Typical Application Circuit. current limiter level. MPP nuclei have very soft saturation characteristics. L= (Vi - Vo) V0 (Vi - Vo) V0 , C= Vi f IL 8L f2 Vo
IL = Inductance current ripple Vo = Output ripple voltage
L 4964
C7, C8 : EKR (ROE)
SUGGESTED INDUCTOR (L1)
Core Type No Turns Wire Gauge (mmm) 1.0 0.8 2 x 0.8 Air Gap (mm) - 0.7 -
Resistor Values for Standard Output Voltages
V0 12 V 15 V 18 V R8 4.7 k 4.7 k 4.7 k R7 6.2 k 9.1 k 12 k
Magnetics 58930 - A2MPP 43 Thomson GUP 20 x 16 x 7 50 Siemens EC 35/17/10 40 (B6633& - G0500 - X127) VOGT 250 H Toroidal Coil, Part Number 5730501800
Figure 14 : P.C. Board and Component Layout of the Circuit of Fig. 13 (1:1 scale)
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L4964
MULTIWATT15 (Vertical) PACKAGE MECHANICAL DATA
Dimensions A B C D E F G G1 H1 H2 L L1 L2 L3 L4 L7 M M1 S S1 Dia. 1 22.1 22 17.65 17.25 10.3 2.65 4.2 4.5 1.9 1.9 3.65 4.3 5.08 17.5 10.7 0.49 0.66 1.14 17.57 19.6 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 0.169 0.200 0.689 0.421 1.27 17.78 1 0.55 0.75 1.4 17.91 0.019 0.026 0.045 0.692 0.772 0.795 0.890 0.886 0.713 0.699 0.429 0.114 0.181 0.209 0.102 0.102 0.152
MUL15V.TBL
Millimeters Min. Typ. Max. 5 2.65 1.6 Min.
Inches Typ. Max. 0.197 0.104 0.063 0.039 0.022 0.030 0.050 0.700 0.055 0.705
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PMMUL15V.EPS
L4964
MULTIWATT15 (Horizontal) PACKAGE MECHANICAL DATA
Dimensions A B C E F G G1 H1 H2 L L1 L2 L3 L4 L5 L6 L7 S S1 Dia. 1 2.65 1.9 1.9 3.65 17.25 10.3 20.57 18.03 2.54 17.5 10.7 5.28 2.38 2.9 2.6 2.6 3.85 0.104 0.075 0.075 0.144 17.75 10.9 0.679 0.406 0.49 0.66 1.14 17.57 19.6 20.2 0.810 0.710 0.100 0.689 0.421 0.208 0.094 0.114 0.102 0.102 0.152 0.699 0.429
MUL15H.TBL PMMUL15H.EPS
Millimeters Min. Typ. Max. 5 2.65 1.6 0.55 0.75 1.27 17.78 1.4 17.91 0.019 0.026 0.045 0.692 0.772 Min.
Inches Typ. Max. 0.197 0.104 0.063 0.022 0.030 0.050 0.700 0.055 0.705 0.795
H1 A L7 C S S1
Dia. 1
L
L1
B E
H2 L2
F L6 L5
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G G1
L4
L3
L4964
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. (c) 1994 SGS-THOMSON Microelectronics - All Rights Reserved MULTIWATT (R) is a Registered Trademark of SGS-THOMSON Microelectrinics 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.
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