SGS Thomson Microelectronics L4973V3.3, L4973D5.1, L4973D3.3, L4973V5.1 Datasheet

L4973V3.3 - L4973V5.1



3.5A STEP DOWN SWITCHING REGULATOR

UPTO3.5ASTE PDOWNCO NVERTER OPERATING INPUT VOLTAGE FROM 8V TO

55V

3.3V AND 5.1V (±1%) FIXED OUTPUT, AND ADJUSTABLEOUTPUTSFROM: 0V TO 50V (3.3V type)

5.1VTO 50V (5.1 type) FREQUENCYADJUSTABLEUP TO300KHz VOLTAGEFEED FORWARD ZERO LOAD CURRENT OPERATION (min

1mA) INTERNAL CURRENT LIMITING (PULSE BY

PULSEAND HICCUPMODE) PRECISE 5.1V (1.5%) REFERENCE VOLT-

AGEEXTERNALLYAVAILABLE INPUT/OUTPUT SYNCHRONIZATION FUNC-

TION INHIBIT FOR ZERO CURRENT CONSUMP-

TION (100µA Typ.at V PROTECTION AGAINST FEEDBACK DIS-

CONNECTION THERMAL SHUTDOWN OUTPUTOVERVOLTAGEPROTECTION SOFTSTART FUNCTION

CC

= 24V)

L4973D3.3 - L4973D5.1

MULTIPOWERBCD TECHNOLOGY

POWERDIP(12+3+3) SO20(12+4+4)

ORDERING NUMBERS:

L4973V3.3 (Powerdip)

L4973D3.3 (SO20)

L4973V5.1 (Powerdip)

L4973D5.1 (SO20)

DESCRIPTION

The L4973 is a step down monolithic power switching regulator delivering 3.5A at fixed voltages of 3.3V or 5.1V and using a simple external divideroutput adjustable voltage up to 50V.

Realized in BCD mixed technology, the device

TYPICAL APPLICATIONCIRCUIT (POWERDIP)

VCC(8V to 55V)

798

R

OSC

L4973

16

April 2000

C

OSC

1

4,5,6,

13,14,15

C

IN

C2

17

C

SS

D97IN554A

10

11

12

3 2

R

C

COMP

BOOT

D1

L1

VO(3.3V or 5.1V)

C

OUT

1/16

L4973V3.3 - L4973V5.1 - L4973D3.3 - L4973D5.1

uses an internal power D-MOS transistor (with a typicalRdson of 0.15ohm) to obtain very high efficiencyand very fast switching times.

Switching frequencyup to 300KHzare achievable (the maximum power dissipation of the packages mustbe observed).

A wide input voltage range between 8V to 55V and output voltages regulated from 3.3V to 40V coverthe majorityof thetoday applications.

Features of this new generation of DC-DC con-

PIN CONNECTIONS(Top view

OSC OUT OUT GND GND GND

V V

BOOT

1 2 3 4 5 6 7

CC

8

CC

9 INH

D94IN162A

POWERDIP (12+3+3)

17 16 15 14 13 12 11 10

)

SYNC18 SS V5.1 GND GND GND VFB COMP

verterincludes pulse by pulse current limit, hiccup mode for output short circuit protection, voltage feed forward regulation, soft start, input/output synchronization,protectionagainst feedback loop disconnection, inhibit for zero current consumptionand thermal shutdown.

Packagesavailable are in plastic dual in line, DIP18 (12+3+3) for standard assembly, and SO20 (12+4+4)for SMD assembly.

OSC OUT OUT GND GND GND GND

V

CC

V

CC

BOOT INH

2 3 4 5 6 7 8 9 10

D94IN163A

20 19 18 17 16 15 14 13 12 11

SO20 (12+4+4)

SYNC1 SS V5.1 GND GND GND GND VFB COMP

BLOCKDIAGRAM

ZERO CURRENT

17(19)

SS

VFB

11(12)

5.1V

3.3V

12(13)

18(20)

Pin x = Powerdip Pin (x) = S020

COMP

SYNC

2/16

INH

INHIBIT

+

E/A

-

V5.1

VREF

GOOD

SOFT

START

THERMAL

SHUTDOWN

-

PWM

+

OSCILLATOR

1(1) 2(2) 3(3)

5.1V

3.3V

(4,5,6,7,14,15,16,17)

INTERNAL

REFERENCE

HICCUP CURRENT

LIMITING

CURRENT

LIMITING

RSQ

4,5,6,13,14,15

INTERNAL

Q

V

SUPPLY

CC

DRIVER

5.1V

V

CC

8(9)7(8)16(18)10(11)

CBOOT

CHARGE

BOOT

9(10)

OUTOUTGNDOSC

D94IN161B

L4973V3 - L4973V5 - L4973D3- L4973D5

THERMALDATA

Symbol Parameter Powerdip SO20 Unit

R

th(j-pin)

R

th(j-amb)

(*) Package mounted on board.

ABSOLUTE MAXIMUM RATINGS

Thermal Resistance Junction to pin Max. 12 15 °C/W Thermal Resistance to Ambient Max. 60 (*) 80 (*) °C/W

Symbol

DIP-18 S0-20

V V

7,V8 2,V3

V9,V V2,V

Input voltage 58 V

8

Output DC voltage

3

Parameter Value Unit

Output peak voltage at t = 0.1µs f=200KHz

V

I

2,I3

9-V8

V V V V

9 11 17 12

I2,I

V10-V

V

10

V

12

Maximum output current int. limit.

3

8

Bootstrap voltage 70 V Analogs input voltage (VCC= 24V) 12 V

14 V

V19 Analogs input voltage (VCC= 24V) 13 V

V

13

(VCC= 20V) 6

-0.3

V

18

V

20

(VCC= 20V) 5.5

-0.3

V

10

V

11

Inhibit Vcc

-0.3

P

T

J,TSTG

tot

Power dissipation a T (T

=70°C no copper area)

amb

(T

=70°C 4cm copper area on PCB)

amb

Power dissipation a T

≤ 90°C

pins

=90°C SO20 4 W

pins

Junction and storage temperature -40 to 150 °C

DIP 12+3+3

1.3

PIN FUNCTIONS

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).

9 10 BOOT A capacitor connected between thispin and the output allows to drive the

18 20 SYNC Input/Output synchronization. 7,8 8,9 Vcc Unregulated DCinput voltage 2,3 2,3 OUT Stepdown regulator output.

12 13 VFB Stepdown feedback input. Connecting the output directly to this pin results

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

If not used it must be connected to GND; if floating the deviceis disabled.

internal D-MOS.

in an output voltage of 3.3V for the L4973V3.3 and 5.1V. An external resistive divider is required for higher outputvoltages. Foroutput voltage less than 3.3V, seenote ** and Figure 32.

Pin 1 and a capacitor connected from Pin 1 to ground fixes the switching frequency. (Line feed forward is automatically obtained)

-1

-5

V V

5

W W

2

W

3/16

L4973V3.3 - L4973V5.1 - L4973D3.3 - L4973D5.1

ELECTRICAL CHARACTERISTICS

R

OSC = 20K

Ω

; unless otherwisespecified)•= specificationsreferredto TJfrom0 to 125°C.

( Referto the test circuit,V

= 24V; Tj=25°C, COSC = 2.7nF;

CC

Symbol Parameter Test Conditions Min. Typ. Max. Unit

DYNAMIC CHARACTERISTICS

Input Voltage Range (*)

Output Voltage L4973V5.1

Output Voltage L4973V3.3

R

DSON

Maximum Limiting Current V

η Efficiency V

Switching Frequency Supply Voltage Ripple

Rejection

Switching Frequency Stability

∆f

sw

vs, Supply Voltage

VO=V I

= 1A 5.05 5.1 5.15 V

O

I

=0.5Ato3.5A 5.00 5.1 5.20 V

O

V

CC

I

= 1A 3.326 3.36 3.393 V

O

I

=0.5Ato3.5A 3.292 3.36 3.427 V

O

V

CC

VCC= 10.5V 0.15 0.22 Ω I

=3.5A

O

CC = 8V to55V O

V

O

V

i =VCC +2VRMS

VO=V VCC= 8V to 55V 2 5 %

to 40V; I

REF

= 8V to 55V

=3.5A • 855V

O

•

4.95 5.1 5.25 V

= 8V to 40V • 3.26 3.36 3.46 V

•

4 4.5 5.5 A

0.35 Ω

= 5.1V; IO=3.5A 90 % = 3.3V; IO=3.5A 85 %

•

90 100 110 KHz 60 dB

;IO=1A; f

ref

ripple

= 100Hz

REFERENCESECTION

Reference Voltage 5.025 5.1 5.175 V

I

Line Regulation I

Load Regulation V

= 0 to 20mA;

ref

V

= 8 to 55V

CC

= 0mA;

ref

V

= 8 to 55V

CC

= 0 to 5mA;

ref

V

= 0 to 20mA

CC

• 4.950 5.1 5.250 V

510mV

2 6

10 25

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

mV mV

INHIBIT

High Level Voltage Low Level Voltage I

source High Level V

I

source Low Level V

DC CHARACTERISTICS

Total Operating Quiescent Current

Quiescent Current Duty Cycle= 0 2.7 4 mA Total stand-by quiescent

current

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

4/16

•

3.0 V

INH INH

=3V = 0.8V

•

10 16 50 µA

•

10 15 50 µA

0.8 V

Duty Cycle= 50% 4 6 mA

V

CC = 24V; V

V

CC = 55V; V

= 5V 100 200 µA

INH

= 5V 150 300 µA

INH

ELECTRICAL CHARACTERISTICS (continued)

Sink Output Current 200 300 µA Supply Voltage Ripple

Rejection

VCOMP = VFB C

=4.7µF 1-5mA load

REF

current DC Open Loop Gain R Transconductance I

L = ∞ 50 60 dB

= -0.1 to 0.1mA;

comp

V

=6V

comp

OSCILLATORSECTION

Ramp valley 0.78 0.85 0.92 V Ramp peak V

CC = 8V 1.9 2.1 2.3 V

V

CC = 55V 9 9.6 10.2 V

Maximum Duty Cycle 95 97 % Maximum Frequency Duty Cycle= 0%; R

13KΩ;C

OSC

SYNC FUNCTION

High Input Voltage VCC= 8V to55V 3.5 V Low Input Voltage V Slave Sink Current 0.15 0.25 0.45 mA Master Output Amplitude I Output Pulse Width no load, V

= 8V to55V 0.9 V

CC

= 3mA 4 4.5 V

source

L4973V3 - L4973V5 - L4973D3- L4973D5

60 80 dB

2.5 mS

=

OSC

= 820pF;

= 4.5V 0.20 0.35 µs

sync

500 KHz

(*) Pulse testingwith a low dutycycle. (**) The maximum power dissipation of thepackage must be observed.

Figure1. EvaluationBoard Circuit

V

CC

C1 C2R2C7

C3 C4 C5

C1=1000µF/63V C2=220nF/63V C3=470nF C4=1µF/50V C5=220pF C6=22nF C7=2.7nF C8=220nF/63V C0=100µF/40V(C9,C10,C11) C12=Optional (220nF) L1=150µHK R1=9.1K R2=20K D1=GI SB560

77310 - 40Turns - 0.9mm

OOLµ

7,8

1 17

16

(DIP18)

L4973

11

10

13,14,15

R1 C6

(V) R3(KΩ) R4(KΩ)

V

O

3.3

5.1 12 15 18 24

12

4,5,6

2,3

D97IN515B

L4973 V3.3

0

2.7 12 16 20 30

9

C8

D1

L1

3

x

C0

C12

V

R3

R4

O

L4973 V5.1

VO(V) R3(KΩ) R4(KΩ)

4.7

5.1 12 15 18 24

6.2

9.1 12 18

0

4.7

5/16