L4973V5.1

L4973V33-L4973V51 STMICROELECTRONICS | Alldatasheet

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L4973V3.3 - L4973V5.1 L4973D3.3 - L4973D5.1 3.5A STEP DOWN SWITCHING REGULATOR UPTO 3.5ASTEP DOWN CONVERTER OPERATING INPUT VOLTAGE FROM 8V TO 55V 3.3V AND 5.1V (±1%) FIXED OUTPUT, AND ADJUSTABLE OUTPUTS FROM: 0V TO 50V (3.3V type) 5.1V TO 50V (5.1 type) FREQUENCY ADJUSTABLE UP TO 300KHz VOLTAGE FEED FORWARD ZERO LOAD CURRENT OPERATION (min 1mA) INTERNAL CURRENT LIMITING (PULSE BY PULSE AND HICCUP MODE) PRECISE 5.1V (1.5%) REFERENCE VOLT- AGE EXTERNALLY AVAILABLE INPUT/OUTPUT SYNCHRONIZATION FUNC- TION INHIBIT FOR ZERO CURRENT CONSUMP- TION (100µA Typ. at V CC = 24V) PROTECTION AGAINST FEEDBACK DIS- CONNECTION THERMAL SHUTDOWN OUTPUT OVERVOLTAGE PROTECTION SOFT START FUNCTION

DESCRIPTION

The L4973 is a step down monolithic power switching regulator delivering 3.5A at fixed volt- ages of 3.3V or 5.1V and using a simple external divider output adjustable voltage up to 50V. Realized in BCD mixed technology, the device April 2000 L4973 VCC (8V to 55V) C IN C2 R OSC C OSC D1 C OUT VO (3.3V or 5.1V) C BOOT 4,5,6, 13,14,15 D97IN554A R COMP C COMP C SS 216 TYPICAL APPLICATION CIRCUIT (POWERDIP) POWERDIP (12+3+3) SO20(12+4+4) ORDERING NUMBERS: L4973V3.3 (Powerdip) L4973D3.3 (SO20) L4973V5.1 (Powerdip) L4973D5.1 (SO20) MULTIPOWER BCD TECHNOLOGY

uses an internal power D-MOS transistor (with a typical Rdson of 0.15ohm) to obtain very high effi- ciency and very fast switching times. Switching frequency up to 300KHz are achievable (the maximum power dissipation of the packages must be observed). A wide input voltage range between 8V to 55V and output voltages regulated from 3.3V to 40V cover the majority of the today applications. Features of this new generation of DC-DC con- verter includes pulse by pulse current limit, hiccup mode for output short circuit protection, voltage feed forward regulation, soft start, input/output synchronization, protection against feedback loop disconnection, inhibit for zero current consump- tion and thermal shutdown. Packages available are in plastic dual in line, DIP- 18 (12+3+3) for standard assembly, and SO20 (12+4+4) for SMD assembly. PIN CONNECTIONS (Top view) OSC OUT OUT GND GND VCC GND VCC BOOT

9 INH

V5.1 SS SYNC18 D94IN162A POWERDIP (12+3+3) OSC OUT OUT GND GND GND GND V CC VCC VFB COMP GND GND GND GND V5.1 SS SYNC1 BOOT INH D94IN163A SO20 (12+4+4) VREF GOOD 5.1V COMP VFB SYNC BOOT DRIVER HICCUP CURRENT LIMITING INTERNAL REFERENCE SS INH ZERO CURRENT INHIBIT D94IN161B 3.3V V5.1 E/A SOFT START 5.1V 3.3V THERMAL SHUTDOWN INTERNAL SUPPLY 5.1V PWM CURRENT LIMITING R S Q Q CBOOT CHARGE OSCILLATOR OUTOUTGNDOSC VCC VCC 17(19) 11(12) 12(13) 18(20) 1(1) 2(2) 3(3) 9(10) 4,5,6,13,14,15 Pin x = Powerdip Pin (x) = S020 BLOCK DIAGRAM L4973V3.3 - L4973V5.1 - L4973D3.3 - L4973D5.1

Powerdip SO20 NAME DESCRIPTION 11 12 COMP E/A output to be used for frequency compensation 10 11 INH A logic signal (active high) disables the device (sleep mode operation). If not used it must be connected to GND; if floating the device is disabled. 9 10 BOOT A capacitor connected between this pin and the output allows to drive the internal D-MOS. 18 20 SYNC Input/Output synchronization. 7,8 8,9 Vcc Unregulated DC input voltage 2,3 2,3 OUT Stepdown regulator output. 12 13 VFB Stepdown feedback input. Connecting the output directly to this pin results in an output voltage of 3.3V for the L4973V3.3 and 5.1V. An external resistive divider is required for higher output voltages. For output voltage less than 3.3V, see note ** and Figure 32. 16 18 V5.1 Reference voltage externally available. 4,5,6 13,14,15 4,5,6,7 14,15,16,17 GND Signal ground 1 1 OSC An external resistor connected between the unregulated input voltage and Pin 1 and a capacitor connected from Pin 1 to ground fixes the switching frequency. (Line feed forward is automatically obtained) ABSOLUTE MAXIMUM RATINGS Symbol Parameter Value Unit DIP-18 S0-20 V7,V8 V9,V8 Input voltage 58 V V2,V3 V2,V3 Output DC voltage Output peak voltage at t = 0.1µs f=200KHz V V I2,I3 I2,I3 Maximum output current int. limit. V9-V8 V10-V8 14 V V9 V10 Bootstrap voltage 70 V V11 V12 Analogs input voltage (VCC = 24V) 12 V V17 V19 Analogs input voltage (VCC = 24V) 13 V V12 V13 (VCC = 20V) 6 -0.3 V V V18 V20 (VCC = 20V) 5.5 -0.3 V V V10 V11 Inhibit Vcc -0.3 V V Ptot Power dissipation a Tpins ≤ 90°C (Tamb =7 0°C no copper area) (Tamb =7 0°C 4cm copper area on PCB) DIP 12+3+3 1.3 W W W Power dissipation a Tpins=9 0°C SO20 4 W TJ,TSTG Junction and storage temperature -40 to 150 °C THERMAL DATA Symbol Parameter Powerdip SO20 Unit R th(j-pin) Thermal Resistance Junction to pin Max. 12 15 °C/W R th(j-amb) Thermal Resistance to Ambient Max. 60 (*) 80 (*) °C/W (*) Package mounted on board. L4973V3 - L4973V5 - L4973D3 - L4973D5

ELECTRICAL CHARACTERISTICS ( Refer to the test circuit,VCC = 24V; Tj=2 5°C, COSC = 2.7nF; R OSC = 20KΩ ; unless otherwise specified)• = specificationsreferred to TJ from 0 to 125°C. Symbol Parameter Test Conditions Min. Typ. Max. Unit DYNAMIC CHARACTERISTICS Input Voltage Range (*)VO =V REF to 40V; IO =3 . 5 A • 85 5 V Output Voltage L4973V5.1 IO = 1A 5.05 5.1 5.15 V VCC = 8V to 55V • 4.95 5.1 5.25 V Output Voltage L4973V3.3 IO = 1A 3.326 3.36 3.393 V VCC = 8V to 40V • 3.26 3.36 3.46 V R DSON VCC = 10.5V 0.15 0.22 Ω IO =3 . 5 A • 0.35 Ω Maximum Limiting Current V CC = 8V to 55V • 4 4.5 5.5 A η Efficiency V O = 5.1V; IO =3. 5A 90 % VO = 3.3V; IO =3. 5A 85 % Switching Frequency • 90 100 110 KHz Supply Voltage Ripple Rejection Vi=V CC +2VRMS VO =V ref;IO = 1A; fripple= 100Hz 60 dB Δ fsw Switching Frequency Stability vs, Supply Voltage VCC = 8V to 55V 2 5 % REFERENCE SECTION Reference Voltage 5.025 5.1 5.175 V Iref= 0 to 20mA; VCC = 8 to 55V

• 4.950 5.1 5.250 V Line Regulation I ref= 0mA; VCC = 8 to 55V 51 0 m V Load Regulation V ref= 0 to 5mA; VCC = 0 to 20mA mV mV Short Circuit Current 30 65 100 mA SOFT START Soft Start Charge Current 30 45 60 µA Soft Start Discharge Current 15 22 30 µA INHIBIT High Level Voltage • 3.0 V Low Level Voltage • 0.8 V IsourceHigh Level V INH =3 V • 10 16 50 µA IsourceLow Level V INH = 0.8V • 10 15 50 µA DC CHARACTERISTICS Total Operating Quiescent Current Duty Cycle = 50% 4 6 mA Quiescent Current Duty Cycle = 0 2.7 4 mA Total stand-by quiescent current VCC = 24V; VINH = 5V 100 200 µA VCC = 55V; VINH = 5V 150 300 µA ERROR AMPLIFIER High Level Output Voltage 11.0 V Low Level Output Voltage 0.65 V Source Bias Current 1 2 3 µA Source Output Current 200 300 600 µA L4973V3.3 - L4973V5.1 - L4973D3.3 - L4973D5.1

500 KHz

(*) Pulse testing with a low duty cycle. (**) The maximum power dissipation of the package must be observed. Figure 1. Evaluation Board Circuit

0123 I O (A)

5.0 5.05 5.1 5.15 VO (V) D97IN640 Tj=25°C Tj=125°C VCC = 35V Figure 10:Load Regulation (see fig. 1c) 0 1 02 03 04 05 0 V CC (V) 3.3 3.31 3.32 3.34 VO (V) 3.33 3.35 D97IN660A Tj=25°C Tj=125°C IO =1 A Figure 11:Line Regulation (see fig. 1d) 3.3 3.31 3.33 3.35 V O (V) 3.32 3.34 D97IN661 Tj=25°C Tj=125°C VCC = 35V Figure 12:Load Regulation (see fig. 1d) 0 20 40 60 80 R2(K Ω ) 100 200 500 fsw (KHz) D97IN630 0.82nF 1.2nF 2.2nF 3.3nF 4.7nF 5.6nF Tamb=25 °C Figure 13:Switching Frequency vs.R2 and C7 (fig. 1) 0 1 02 03 04 05 0 V CC (V) 100 105 fsw (KHz) D97IN631 Tamb=25 °C Figure 14:Switching Frequency vs. Input Voltage -50 0 50 100 Tj( °C) 100 105 fsw (KHz) D97IN632 Figure 15:Switching Frequency vs. Junction temperature (see fig. 1) L4973V3 - L4973V5 - L4973D3 - L4973D5

0.2 0.4 0.6 Δ V (V) D97IN643 Tj=0°C Tj=125°C Tj=25 Figure 16:Dropout Voltage Between pin 7,8 and 2,3 01 0 2 0 3 0 V O (V)40 η (%) D97IN641 200KHz 100KHz IO = 3A VCC = 50V Figure 17:Efficiency vs. Output Voltage (see fig.1) 0 1 01 52 0 V O (V)3052 5 η (%) D97IN642 200KHz 100KHz IO = 3A VCC = 35V Figure 18:Efficiencyvs. Output Voltage (Diode STPS745D) η (%) D97IN645 Vcc=12V Vcc=24V Vcc=48V VO = 5.1V fsw = 100KHz Figure 19:Efficiency vs. Output Current ( see fig.1c) η (%) D97IN646 Vcc=12V Vcc=24V Vcc=48V VO = 5.1V fsw = 200KHz Figure 20:Efficiencyvs. Output Current (see fig.1c) η (%) D97IN644 Vcc=12V Vcc=24V Vcc=48V V O = 3.3V fsw = 100KHz Figure 21:Efficiency vs. Output Current (see fig.1d) L4973V3.3 - L4973V5.1 - L4973D3.3 - L4973D5.1

DIM. mm inch a1 0.51 0.020 B 0.85 1.40 0.033 0.055 b 0.50 0.020 b1 0.38 0.50 0.015 0.020 D 24.80 0.976 E 8.80 0.346 e 2.54 0.100 e3 20.32 0.800 F 7.10 0.280 I 5.10 0.201 L 3.30 0.130 Z 2.54 0.100 OUTLINE AND MECHANICAL DATA L4973V3.3 - L4973V5.1 - L4973D3.3 - L4973D5.1

A eB D E L K H A1 C SO20MEC hx4 5° SO20 DIM. mm inch A 2.35 2.65 0.093 0.104 A1 0.1 0.3 0.004 0.012 B 0.33 0.51 0.013 0.020 C 0.23 0.32 0.009 0.013 D 12.6 13 0.496 0.512 E 7.4 7.6 0.291 0.299 e 1.27 0.050 H 10 10.65 0.394 0.419 h 0.25 0.75 0.010 0.030 L 0.4 1.27 0.016 0.050 K0 °(min.)8°(max.) OUTLINE AND MECHANICAL DATA L4973V3 - L4973V5 - L4973D3 - L4973D5

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