L4960

L4960 STMICROELECTRONICS | Alldatasheet

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 L4960 2.5A POWER SWITCHING REGULATOR 2.5A OUTPUT CURRENT 5.1V TO 40V OPUTPUT VOLTAGE RANGE PRECISE (± 2%) ON-CHIP REFERENCE HIGH SWITCHING FREQUENCY VERY HIGH EFFICIENCY (UP TO 90%) VERY FEW EXTERNAL COMPONENTS SOFT START INTERNAL LIMITING CURRENT THERMAL SHUTDOWN

DESCRIPTION

The L4960 is a monolithic power switching regula- tor delivering 2.5A at a voltage variable from 5V to 40V in step down configuration. Features of the device include current limiting, soft start, thermal protection and 0 to 100% duty cycle for continuous operation mode. June 2000 ORDERING NUMBERS : L4960 (Vertical) L4960H (Horizontal) HEPTAWATT BLOCK DIAGRAM TheL4960 is mounted ina Heptawattplastic power package and requires very few external compo- nents. Efficient operation at switching frequencies up to 150KHz allows a reduction in the size and cost of external filter components.

PIN CONNECTION (Top view) N ° NAME FUNCTION 1 SUPPLY VOLTAGE Unregulated voltage input. An internal regulator powers the internal logic. 2 FEEDBACK INPUT The feedback terminal of the regulation loop. The output is connected directly to this terminal for 5.1V operation; it is connected via a divider for higher voltages.

3 FREQUENCY

A series RC network connected between this terminal and ground determines the regulation loop gain characteristics. 4 GROUND Common ground terminal.

5 OSCILLATOR A parallel RC network connected to this terminal determines the

switching frequency. 6 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. 7 OUTPUT Regulator output. PIN FUNCTIONS Symbol Parameter Value Unit V1 Input voltage 50 V V1 -V 7 Input to output voltage difference 50 V V7 Negative output DC voltage -1 V Negative output peak voltage at t = 0.1µs; f = 100KHz -5 V V3,V 6 Voltage at pin 3 and 6 5.5 V V2 Voltage at pin 2 7V I3 Pin 3 sink current 1 mA I5 Pin 5 source current 20 mA Ptot Power dissipation at Tcase ≤ 90°C1 5 W Tj,Tstg Junction and storage temperature -40 to 150 °C ABSOLUTE MAXIMUM RATINGS L4960

Symbol Parameter Test Conditions Min. Typ. Max. Unit DYNAMIC CHARACTERISTICS Vo Output voltage range V i = 46V I o =1 A V ref 40 V Vi Input voltage range V o =V refto 36V I o = 2.5A 9 46 V Δ Vo Line regulation V i = 10V to 40V Vo =V ref Io =1 A 1 5 5 0 m V Δ Vo Load regulation V o =V ref Io = 0.5A to 2A 10 30 mV Vref Internal reference voltage (pin 2) Vi = 9V to 46V I o = 1A 5 5.1 5.2 V Δ Vref Δ T Average temperature coefficient of refer voltage Tj=0 °C to 125°C Io =1 A 0.4 mV/ °C Vd Dropout voltage I o = 2A 1.4 3 V Iom Maximum operating load current Vi = 9V to 46V Vo =V refto 36V 2.5 A I7L Current limiting threshold (pin 7) Vi = 9V to 46V Vo =V refto 36V 3 4.5 A ISH Input average current V i = 46V; output short-circuit 30 60 mA η Efficiency f = 100KHz V o =V ref 75 % Io =2 A V o = 12V 85 % SVR Supply voltage ripple rejection Δ Vi=2 Vrms fripple= 100Hz Vo =V ref Io = 1A 50 56 dB f Switching frequency 85 100 115 KHz Δ f Δ V i Voltage stability of switching frequency Vi = 9V to 46V 0.5 % Δ f Δ Tj Temperature stability of switching frequency Tj=0 °C to 125°C1 % fmax Maximum operating switching frequency Vo =V ref Io = 2A 120 150 KHz Tsd Thermal shutdown junction temperature 150 °C ELECTRICAL CHARACTERISTICS (Refer to the test circuit, Tj =2 5 °C, Vi = 35V, unless otherwise specified) Symbol Parameter Value Unit R th j-case Thermal resistance junction-case max 4 °C/W R th j-amb Thermal resistance junction-ambient max 50 °C/W THERMAL DATA L4960

Symbol Parameter Test Conditions Min. Typ. Max. Unit DC CHARACTERISTICS I1Q Quiescent drain current 100% duty cycle pins 5 and 7 open Vi= 46V 30 40 mA 0% duty cycle 15 20 mA -I7L Output leakage current 0% duty cycle 1 mA SOFT START I6SO Source current 100 140 180 µA I6SI Sink current 50 70 120 µA ERROR AMPLIFIER V3H High level output voltage V2 = 4.7V I 3 = 100µA 3.5 V V3L Low level output voltage V 2 = 5.3V I 3 = 100µA 0.5 V I3SI Sink output current V 2 = 5.3V 100 150 µA -I3SO Source output current V 2 = 4.7V 100 150 µA I2 Input bias current V 2 = 5.2V 2 10 µA G v DC open loop gain V 3 =1 Vt o3 V 4 6 5 5 d B OSCILLATOR -I5 Oscillator source current 5 mA ELECTRICAL CHARACTERISTICS (continued) L4960

Figure 28. Microcomputer supply with + 5.1V, -5V, +12V and -12V outputs

Figure 30. - In multiple supplies several L4960s can be synchronized as shown

DIM. mm inch A 4.8 0.189 C 1.37 0.054 D 2.4 2.8 0.094 0.110 D1 1.2 1.35 0.047 0.053 E 0.35 0.55 0.014 0.022 E1 0.7 0.97 0.028 0.038 F 0.6 0.8 0.024 0.031 F1 0.9 0.035 H2 10.4 0.409 H3 10.05 10.4 0.396 0.409 L1 14.92 0.587 L4 1.29 0.051 L7 6 6.35 6.6 0.236 0.250 0.260 L9 0.2 0.008 V4 40 ° (typ.) Dia 3.65 3.85 0.144 0.152 A L C D E M Dia. F1H2 F GG 1 G 2 F E VV HEPTAMEC OUTLINE AND MECHANICAL DATA L4960

DIM. mm inch A 4.8 0.189 C 1.37 0.054 D 2.4 2.8 0.094 0.110 D1 1.2 1.35 0.047 0.053 E 0.35 0.55 0.014 0.022 F 0.6 0.8 0.024 0.031 F1 0.9 0.035 H2 10.4 0.409 H3 10.05 10.4 0.396 0.409 L 14.2 0.559 L1 4.4 0.173 L2 15.8 0.622 L3 5.1 0.201 L5 2.6 3 0.102 0.118 L6 15.1 15.8 0.594 0.622 L7 6 6.6 0.236 0.260 L9 4.44 0.175 Dia 3.65 3.85 0.144 0.152 OUTLINE AND MECHANICAL DATA L4960

Information furnished is believed to be accurate and reliable. However, STMicroelectronics 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 STMicroelectronics. Specification mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics. The ST logo is a registered trademark of STMicroelectronics  2000 STMicroelectronics – Printed in Italy – All Rights Reserved STMicroelectronics GROUP OF COMPANIES Australia - Brazil - China - Finland - France - Germany - Hong Kong - India - Italy - Japan - Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - U.S.A. http://www.st.com L4960