SGS Thomson Microelectronics L4955V3.3, L4955, L4955V5.1 Datasheet



L4955

5A ULDO LINEAR REGULATORS FAMILY

UP TO 5A OUTPUTCURRENT

2% PRECISEOUTPUT VOLTAGES

±

FASTTRANSIENTRESPONSE

0.75VTYP. DROP OUT VOLTAGEAT 5A
OPERATINGINPUT VOLTAGEFROM 4.5V
ADJUSTABLEVERSION:

= 1.26V

• V

O

• INHIBIT(I
POWERGOOD

•

PROGRAMMABLECURRENT LIMIT

•

= 120µA TYP.)

Q

• HEPTAWATT PACKAGE

FIXED VERSION:

• 3.3V,5.1V OUTPUTS
VERSAWATTPACKAGE

•

VERYLOW QUIESCENTCURRENT
SHORT CIRCUIT PROTECTION (Foldback

function)
THERMALSHUTDOWN

APPLICATIONS

PENTIUMANDPOWER PCSUPPLIES
POSTREGULATOR FOR SMPS
LOW COST SOLUTION FOR 5V TO 3.3V

CONVERSION
LOW COST BATTERYCHARGER
CONSTANT CURRENT REGULATOR
SUITABLE FOR APPLICATION WITH

STANDBYFEATURE

DESCRIPTION

The L4955 is a familyof monolithic ultra very low
drop linear regulators designed to supply the
most recent microprocessors.

TYPICALAPPLICATIONS

MULTIPOWER BCD TECHNOLOGY

HEPTAWATT VERSAWATT

ORDERING

NUMBERS

L4955 1.26V ADJ HEPTAWATT
L4955V3.3 3.3V VERSAWATT
L4955V5.1 5.1V VERSAWATT

OUTPUT

VOLTAGE

(TO-220)

PACKAGE

The dropout voltage is only 0.75V (Typ.) at 5A, di­rectly dependenton the output current conditions.

Realized in BCDII technology, it has on board a
charge pump to properly drive an N-channel
powermos Transistorwith 150mΩof R

DSON

.

It operates from a 4.5V minimum supply, with a
very low quiescent current irrespective of the
load; a minimum of 22µF output capacitor is re­quired for stability.

The on-chip trimming techniques improve the pre­cisionof the availableoutputvoltages to±2%.

Ancillary functions like power good, inhibit with
low power consumption, programmable output
voltage and current limiting make the flexible
heptawatt version usable in applications where
power management, stand-by, features, post
regulation and adjustable current generators for
batterychargers are important.

V

IN

C1

February 1999

INH PG

1

CL GND

63

L4955

24

OUTIN

7

R1

ADJ

5

R2

D97IN589

C2

V

OUT

V

IN

C1

1

L4955VXXX

2

GND

3

D97IN590

OUTIN

C2

V

OUT

1/14

L4955

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter Value Unit

V

IN

P

TOT

T

st,Ti

PIN CONNECTIONS (Top views)

tab connected to pin 4

Supply InputVoltage 24 V
ADJ and CL pins

PG and INH pins
Power Dissipation @ T

Power Dissipation @ T

amb
case

=50°C

=90°C

-0.3 to 4
0toV

2

15

IN

Storage Temperature -40 to +150 °C

7 OUT
6
5
4
3
2
1

D96IN367

PG
ADJ
GND
INH
CL
IN

3

1

D96IN369

V
V

W
W

OUT

GND

IN

HEPTAWATT

BLOCK DIAGRAM

10µF

IN

1(1)

REGULATOR

3

INH

1.26V
ACTIVE HIGH

PIN x =
PIN (x) = VERSAWATT

INHIBIT

V

IN

PRE

HEPTAWATT

V

REF

1.26V

V

REF

=

+

-

+

-

(1/4W, 1%)

VERSAWATT

(TO220)

FIXED

C.L.

E/A

PROGRAM.

C.L.

26

RCL

FOLDBACK

0.9V

REF

4(2)

+

-

GND PGCL

CHARGE

BUFFER

THERMAL

SHUTDOWN

PUMP

POWER

DMOS

150mΩ

D96IN366

OUT

7(3)

ADJ

5

R1 22µF

R2

V

OUT

2/14

PIN FUNCTIONS

HW VW Name Function

1 1 IN Unregulated input voltage; this pin must be bypassed with a capacitor larger than 10µF.
2 – CL A resistor connected between this pin and ground sets the programmable current limiting

value. When the programmable current limiting is not used the pin must be connected to GND.

3 – INH TTL-CMOS input. A logic high level on this input disables the device. An internal pull-down

insures full functionally even if the pin is open.
4 2 GND Ground.
5 – ADJ The output is connected directly to this terminal for 1.26V operation; it is connected to the

output through a resistivedivider for higher voltages.
6 – PG Opendrainoutput, this signal islow when the outputvoltage is lower than 90%,otherwise is high.
7 3 OUT Regulated output voltage. A minimum bypass capacitor of 22µF is requiredto insure stability.

L4955

THERMAL DATA

(HEPTAWATT& VERSAWATTpackages)

Symbol Parameter Value Unit

R

th j-case

R

th j-amb

Thermal ResistanceJunction-case Max. 2.5 °C/W
Thermal ResistanceJunction-ambient Max. 50 °C/W
Thermal Shutdown Typ. 150 °C
Thermal Hysteresis Typ. 20 °C

L4955 - ELECTRICAL CHARACTERISTICS (Tj=25°C, Vin= 12V, unless otherwise specified).

•

= Specificationsreferredto TJfrom0°Cto +125°C.

Symbol Parameter Test Condition Min. Typ. Max. Unit

V

IN

V

O

V

∆
∆V

V

O

I

O

I

Q

(1) Output voltage connected to ADJ.

OperatingSupply Voltage 4.5 22 V
Output Voltage (1) 0.1A< IO<5A; 4.5V< VIN<12V 1.235 1.26 1.285 V

4.5V < V

Line regulation (1) 4.5V < VIN<22V; IO= 10mA 2 10 mV

O

Load regulation (1) 0.1A < IO < 5A 2 10 mV

O

<12V; 0.1A< I

IN

Dropout Voltage IO=5A

V

4.5V

≥

IN

=2A • 0.55 0.75 V

I

O

<5A • 1.222 1.26 1.298 V

O

0.75 1.1 V

• 1.1 1.5 V

Current Limiting • 5.1 6.3 7.5 A

Short Circuit Current V
Programmable Current

Limiting
Quiescent Current 0.1A < IO<5A CL=0

=0V • 1.8 A

O

R
R

lim
lim

= 13kΩ
= 47k

Ω

•

•

2.55

0.7030.85
2

C

= 13k

L

2.7
Stand By Current INH = 5V 120 200
Inhibit Threshold Rising Edge

• 1.1 1.26 1.42 V

Inhibit Hysteresis 0.2 V
Inhibit Bias Sink Current INH = 5V or 0.8V 20 60
Power Good Threshold Rising Edge 0.9x V
Power Good Hysteresis
Power Good Saturation I

PG

= 4mA

Ripple Rejection f = 120Hz,I

V

=6V∆VIN=2V

IN

O

=5A

PP

• 0.2 V

•

60 75 dB

O

0.1 0.4 V

3.45

1.00
3

4

A
A

mA
mA

µ

µ

V

A

A

3/14

L4955

L4955V3.3 - ELECTRICAL CHARACTERISTICS

•

= Specificationsreferredto TJfrom0°Cto +125°C.

=25°C, Vin= 5V,unless otherwise specified)

(T

j

Symbol Parameter Test Condition Min. Typ. Max. Unit

V
V

∆
∆V

IN

O

V

I

O

I

Q

Operating Input Voltage 4.5 22 V
Output Voltage 4.75V< VIN<12V; 0.1A< IO< 5A 3.234 3.300 3.366 V

4.75V< V

Line regulation 4.5V < VIN<12V; IO= 10mA 2 10 mV

O

Load regulation 0.1A < IO < 5A 3 15 mV

O

<12V; 0.1A< I

IN

<5A • 3.201 3.300 3.399 V

O

Current Limiting • 5.1 6.3 7.5 A

Short Circuit Current V

=0V • 1.8 A

O

Quiescent Current 0.1A < IO<5A 2 3 mA
Ripple Rejection f = 120Hz,I

V

=6V∆VIN=2V

IN

O

=5A

PP

57 70 dB

L4955V5.1 - ELECTRICAL CHARACTERISTICS (Tj=25°C, Vin= 8V,unless otherwise specified)

•

= Specificationsreferredto TJfrom0°Cto +125°C.

Symbol Parameter Test Condition Min. Typ. Max. Unit

V

IN

V

O

V

D

Operating Input Voltage VO+V

D

Output Voltage 6.75V< VIN<15V; 0.1A< IO< 5A 5.000 5.100 5.200 V

6.75V < V

< 15V; 0.1A< I

IN

<5A • 4.950 5.100 5.250 V

O

Drop-out Voltage IO= 5A 0.75 1.1 V

22 V

• 1.1 1.5 V

=2A • 0.55 0.75 V

I

O

∆V
∆V

I

O

I

Q

Line regulation 6.5V < VIN<15V; IO= 10mA 2 10 mV

O

Load regulation 0.1A < IO < 5A 5 20 mV

O

Current Limiting • 5.1 6.3 7.5 A

Short Circuit Current V

=0V • 1.8 A

O

Quiescent Current 0.1A < IO<5A 2 3 mA
Ripple Rejection f = 120Hz,I

V

=8V∆VIN=2V

IN

O

=5A

PP

55 65 dB

4/14

L4955

L4955

Figure 1:

Ou tput C urrent [A ]

8
7
6
5
4
3
2
1
0

0 2.5 5 7.5 10 12.5 15 17.5 20 22.5

L4955 DC Operating Area

Current Lim itation

Rdson

limit

DC O perating A rea

Power D issipation Lim it

(Vin - Vout) [V]

Vin > 4.5V
Tj = 125°C

Tc = 25°C
Pdm ax = 40W

Tc = 70°C
Pdmax = 22W

Figure 3: LineRegulationvs. Junction

Temperature

5

4.5
4

3.5
3

2.5
2

1.5
1

Output Voltage Deviation [m V

0.5

0

-40 -20 0 20 40 60 80 100 120 140 160

Figure 5:

1.25

0.75

M in im u m V in - Vo u t Vo lta g e [V ]

0.25

DropoutVoltage

1

0.5

0

0123456

4.5V <Vin<22V
Iout=10mA

Tj[°C]

Tj = 125 °C

Tj= 25 °C

Tj= -40°C

Pulsed techniq ue has b een used

Iout [A]

Figure2:

OutputVoltage Stabilityvs. Junction
Temperature

Vout [V]

1.28

1.275

1.27

1.265

1.26

1.255

1.25

1.245

1.24

-40 0 40 80 120 160

Vin=12V

Iout=10m A

Tj [°C]

Figure4: Load Regulation

5
4
3
2
1
0

-1

-2

Output Voltage Deviation [m V ]

-3

-4

-5
012345

Figure6:

MaximumOutputCurrentvs.Junction

(Pulsed techn ique has been used)

Vin = 12V
Tj= 25 °C

Vo u t = V

Iou t [ A ]

ADJ

Temperatur ewithinternalcurrentlimiti ng

O utp ut C urre n t [A]

10

9
8
7
6
5
4
3
2
1
0

-40 -20 0 20 40 60 80 100 120 140 160

*Pulsed tecnique has been used

(Vin-Vout) > 2V

pin 2 = GND

Tj [°C]

5/14