L4955V3.3 ,5A ULDO LINEAR REGULATORS FAMILYELECTRICAL CHARACTERISTICS (T =25°C, V = 12V, unless otherwise specified).j in• = Specificationsref ..
L4955V33 ,5A ULDO LINEAR REGULATORS FAMILYL4955 5A ULDO LINEAR REGULATORS FAMILYUP TO 5A OUTPUT CURRENTMULTIPOWER BCD TECHNOLOGY2% PRECISE O ..
L4955V5.1 ,5A ULDO LINEAR REGULATORS FAMILYAPPLICATIONScharge pump to properly drive an N-channelPENTIUM AND POWER PC SUPPLIESpower mos Tran ..
L4956 ,5A LOW DROP LINEAR REGULATORABSOLUTE MAXIMUM RATINGSSymbol Parameter Value UnitV ,V Supply Input Voltage 7 VPW SIGADJ pin -0.3 ..
L4957AD1.5TR ,UP TO 5A ULTRA LOW DROP OUPUT LINEAR REGULATORAPPLICATIONSL4957AV1.5 L4957AD1.5L4957AV1.8 L4957AD1.8M ..
L4957AD1.8 ,UP TO 5A ULTRA LOW DROP OUPUT LINEAR REGULATORAPPLICATIONSL4957AV1.5 L4957AD1.5L4957AV1.8 L4957AD1.8M ..
LBC2012T1R0M , WOUND CHIP INDUCTORS
LBC2012T4R7M , WOUND CHIP INDUCTORS
LBC2518T1R0M , WOUND CHIP INDUCTORS
LBC2518T1R0M , WOUND CHIP INDUCTORS
LBC2518T3R3M , WOUND CHIP INDUCTORS
LBC2518T4R7M , WOUND CHIP INDUCTORS
L4955-L4955V3.3-L4955V33-L4955V5.1
5A ULDO LINEAR REGULATORS FAMILY
L4955 ULDO LINEAR REGULATORS FAMILY TO 5A OUTPUT CURRENT
±2% PRECISE OUTPUT VOLTAGES
FASTTRANSIENT RESPONSE
0.75V TYP. DROP OUT VOLTAGEAT 5A
OPERATING INPUT VOLTAGEFROM 4.5V
ADJUSTABLE VERSION:VO= 1.26V• INHIBIT(IQ= 120μA TYP.) POWER GOOD PROGRAMMABLECURRENT LIMIT HEPTAWATT PACKAGE
FIXED VERSION: 3.3V,5.1V OUTPUTS VERSAWATT PACKAGE
VERY LOW QUIESCENT CURRENT
SHORT CIRCUIT PROTECTION (Foldback
function)
THERMAL SHUTDOWN
APPLICATIONSPENTIUM ANDPOWER PC SUPPLIES
POST REGULATOR FOR SMPS
LOW COST SOLUTION FOR 5V TO 3.3V
CONVERSION
LOW COST BATTERY CHARGER
CONSTANT CURRENT REGULATOR
SUITABLE FOR APPLICATION WITH
STANDBY FEATURE
DESCRIPTIONThe L4955isa familyof monolithic ultra very low
drop linear regulators designed to supply the
most recent microprocessors.
The dropout voltageis only 0.75V (Typ.)at 5A,di-
rectly dependenton the output current conditions.
Realizedin BCDII technology,it has on boarda
charge pump to properly drive an N-channel
power mos Transistor with 150mΩof RDSON. operates froma 4.5V minimum supply, witha
very low quiescent current irrespective of the
load;a minimumof 22μF output capacitoris re-
quiredfor stability.
The on-chip trimming techniques improve the pre-
cisionof the available output voltagesto ±2%.
Ancillary functions like power good, inhibit with
low power consumption, programmable output
voltage and current limiting make the flexible
heptawatt version usablein applications where
power management, stand-by, features, post
regulation and adjustable current generators for
battery chargers are important.
February 1999
TYPICAL APPLICATIONS
HEPTAWATT VERSAWATT
(TO-220)
MULTIPOWER BCD TECHNOLOGY
ORDERING
NUMBERS
OUTPUT
VOLTAGE PACKAGE
L4955 1.26V ADJ HEPTAWATT
L4955V3.3 3.3V VERSAWATT
L4955V5.1 5.1V VERSAWATT
L4955 GND
ADJ
OUTIN
INH PG2431
VIN
VOUT
D97IN589
L4955VXXX
GND
OUTIN 3
VIN
VOUT
D97IN590
1/14
VERSAWATT
(TO220)
ABSOLUTE MAXIMUM RATINGS
Symbol Parameter Value UnitVIN Supply InputVoltage 24 V
ADJ andCL pins and INH pins
-0.3to4
0toVIN
PTOT Power Dissipation@ Tamb =50°C
Power Dissipation@ Tcase =90°C
Tst,Ti Storage Temperature -40to +150 °C
PIN CONNECTIONS (Top views)
HEPTAWATT OUT
ADJ
GND
INH
D96IN367tabconnectedto pin4
OUT
GND1
D96IN369
PROGRAM.
C.L.
PRE
REGULATOR
VREF=
1.26VE/A
OUT
ADJ
GND PGCL D96IN366
1(1)4(2)
7(3)
PINx =HEPTAWATT
PIN(x) =VERSAWATT
INHIBIT
ACTIVE HIGH
1.26V
INH
VIN
10μF
FIXED
C.L.
THERMAL
SHUTDOWN
FOLDBACK
BUFFER
CHARGE
PUMP
POWER
DMOS
150mΩ
VREF0.9VREF 22μF
VOUT
RCL
(1/4W,1%)
BLOCK DIAGRAM
L49552/14
L4955- ELECTRICAL CHARACTERISTICS(Tj =25°C, Vin= 12V, unlessotherwise specified).•= SpecificationsreferredtoTJ from 0°Cto +125°C.
Symbol Parameter Test Condition Min. Typ. Max. UnitVIN Operating Supply Voltage 4.5 22 V Output Voltage (1) 0.1A
4.5VΔVO Line regulation (1) 4.5VΔVO Load regulation (1) 0.1AVIN≥ 4.5V
0.75 1.1 V 1.1 1.5 V =2A • 0.55 0.75 V Current Limiting • 5.1 6.3 7.5 A
Short Circuit Current VO =0V • 1.8 A
Programmable Current
Limiting
Rlim= 13kΩ
Rlim= 47kΩ ••
1.00 Quiescent Current 0.1AStandBy Current INH=5V 120 200 μA
Inhibit Threshold Rising Edge • 1.1 1.26 1.42 V
Inhibit Hysteresis 0.2 V
Inhibit Bias Sink Current INH=5Vor 0.8V 20 60 μA
Power Good Threshold Rising Edge 0.9xVO V
Power Good Hysteresis • 0.2 V
Power Good Saturation IPG= 4mA • 0.1 0.4 V
Ripple Rejection f= 120Hz,IO =5A
VIN =6V ΔVIN =2VPP 75 dB
(1)Outputvoltage connectedto ADJ.
THERMAL DATA (HEPTAWATT& VERSAWATT packages)
Symbol Parameter Value Unit
Rth j-case Thermal Resistance Junction-case Max. 2.5 °C/W
Rthj-amb Thermal Resistance Junction-ambient Max. 50 °C/W
Thermal Shutdown Typ. 150 °C
Thermal Hysteresis Typ. 20 °C
PIN FUNCTIONS VW Name Function 1 IN Unregulated input voltage; thispin mustbe bypassed witha capacitor larger than 10μF. – CL A resistor connected between thispin and ground sets the programmable current limiting
value. Whenthe programmable current limitingisnot used thepin mustbe connectedto GND. – INH TTL-CMOS input.A logic high level onthis input disablesthe device.An internal pull-down
insuresfull functionally evenif thepinis open. 2 GND Ground. – ADJ The outputis connected directlyto this terminalfor 1.26V operation;itis connectedto the
output througha resistive dividerfor higher voltages. – PG Opendrain output, thissignalislow when theoutput voltageis lower than 90%, otherwiseis high. 3 OUT Regulated output voltage.A minimum bypass capacitorof 22μFis requiredto insure stability.
L4955
3/14
L4955V5.1- ELECTRICAL CHARACTERISTICS(Tj =25°C,Vin= 8V, unless otherwise specified)•= SpecificationsreferredtoTJ from 0°Cto +125°C.
Symbol Parameter Test Condition Min. Typ. Max. Unit
VIN Operating Input Voltage VO+VD 22 V Output Voltage 6.75V< VIN< 15V; 0.1A 6.75VΔVO Line regulation 6.5VΔVO Load regulation 0.1AShort Circuit Current VO =0V • 1.8 A Quiescent Current 0.1ARipple Rejection f= 120Hz,IO =5A
VIN =8V ΔVIN =2VPP 65 dB
L4955V3.3- ELECTRICAL CHARACTERISTICS(Tj =25°C,Vin= 5V, unless otherwise specified)•= SpecificationsreferredtoTJ from 0°Cto +125°C.
Symbol Parameter Test Condition Min. Typ. Max. Unit
VIN Operating Input Voltage 4.5 22 V Output Voltage 4.75V< VIN< 12V; 0.1A 4.75V< VIN< 12V; 0.1A ΔVO Line regulation 4.5VΔVO Load regulation 0.1AShort Circuit Current VO =0V • 1.8 A Quiescent Current 0.1ARipple Rejection f= 120Hz,IO =5A
VIN =6V ΔVIN =2VPP 70 dB
L4955
4/14
-40 0 40 80 120 1601.24
1.28 [°C]
Vout[V]
Vin=12V
Iout=10mA
Figure2: Output Voltage Stabilityvs. Junction
Temperature
-40 -200 20 40 60 80 100 120 140 1600
4.5 [°C]
Output
Voltage
Deviation
4.5V Iout=10mA
Figure3: Line Regulationvs. Junction
Temperature
012 345-5
Iout[A]
utput
Voltage
eviation
Vin= 12V=25°C ulsed techn ique has been used)
Vout= VADJ
Figure4: Load Regulation 2.5 5 7.5 10 12.5 15 17.5 20 22.50
(Vin- Vout)[V]
Output Current [A]
Vin> 4.5V= 125°C
Power Dissipation Limit= 25°C
Pdmax= 40W
Current Limitation= 70°C
Pdmax= 22W Operating Area
Rdson
limit
Figure1: L4955 DC Operating Area 123 45 6
Iout[A]
lta=125°C=25°C=-40°C ulsedte chniquehasbeen used
Figure5: Dropout Voltage
*Pulsed tecniquehas been used
-40 -20 0 20 40 60 80 100 120 140 1600 [°C]
Output Current [A]
(Vin-Vout)>2V
pin2= GND
Figure6: Maximum OutputCurrentvs. Junction
Temperaturewith internalcurrentlimiting
L4955
L4955
5/14
0-20 0 204 06 080100120140 1600.42.6 [°C][mA]
Vin=12Vut=10mAto5A
Figure8: Quiescent Current vs. Temperature
(CL= 0V)10 100 10k 100k0
100eq uency[Hz] ippleRe jection[dB]in= 22uFout=22uFut= 1.26V
Vinmin= 4.5V
Iout=5A
Vripple= 3Vp-p Vripple= 0.5Vp-p
Figure 12: Ripple Rejection vs. Frequency
*Pulsed tecniquehas been used
-40 -20 0 2040 60 80 100 120 140 1600
3.5 [°C] hort-circuit Current [A]
Rlim= 47kΩlim= 13kΩlim= 19kΩ
Figure7: Short-circuit Current vs. Junction
Temperature with Programmable
Current Limiting 5 10 15 20 250
Vin[V][mA]
Io=10mAto5A
Tj= 25°C
Tj= 125°C
Tj=-40°C
Figure9: Quiescent Current vs. Supply voltage
(CL= 0V)= 25°C 5 10 15 20 250
Vin[V] [mA]
Rlim= 13kΩ
Rlim= 47kΩ
Figure 10: QuiescentCurrent vs. Supply Voltage
with Programmable Current Limiting 5 10 15 20 250
Vin[V] [uA]
Tj=25°C
Figure 11: Stand-byCurrent vs. Supply Voltage
with INH= LOGIC HIGH
L4955
L4955
6/14
VADJ
0.9 VADJ
hyst= 200mV
HighLow Low
D96IN364B
VOUT=VADJ(R1+R2)/R2
Figure 14: Power Good Function
VINH
Vref= 1.26V
hyst= 200mV
regulator
OFF
regulator
regulator
D96IN365A
Figure 15: Inhibit Function 23 4500ut[A]ippleRejection[dB]
Fripple= 120Hz
Vripple=3Vp-p
Frip ple=1 0kHz
Vripple=0.5Vp-p
Frip ple=1 kHz ripple=0.5Vp-p ripple=50kHz ripple=0.5Vp-pin= 22uF out=2 2uFut=1 .26V
Vinmin=4.5V
Figure 13: Ripple Rejection vs. Output Current
L4955
L4955
7/14
