L4957AV15 ,UP TO 5A ULDO LINEAR REGULATORBLOCK DIAGRAMINVIN110μFCHARGE CURRENT PUMPVREFLIMIT+ BUFFER POWER PRE E/ADMOS REGULATOR-200mΩOUTTHE ..
L4957AV2.5 ,UP TO 5A ULTRA LOW DROP OUPUT LINEAR REGULATORL4957A®UP TO 5A ULDO LINEAR REGULATOR1.5V, 1.8V, 2.5V AND 3.3V FIXED OUTPUTMULTIPOWER BCD TECHNOLOG ..
L4957AV3.3 ,UP TO 5A ULTRA LOW DROP OUPUT LINEAR REGULATORBLOCK DIAGRAMINVIN110m FCHARGECURRENTPUMPVREFLIMIT+ BUFFER POWERPREE/ADMOSREGULATOR-200mWOUTTHERMAL ..
L4957D1.5 ,UP TO 4A ULDO LINEAR REGULATORAPPLICATIONSL4957V1.5 L4957D1.5MOTHER BOARDSL4957V2.5 L4957D2.5PROCESSOR I/O & SUPPLIESLOW VOLTAGE ..
L4957D-1.5 ,UP TO 4A ULDO LINEAR REGULATORBLOCK DIAGRAMINVIN110μFCURRENT CHARGE LIMIT PUMPVREF WITH FOLDBACK+ BUFFER POWER PRE E/ADMOS REGULA ..
L4957D2.5 ,UP TO 4A ULDO LINEAR REGULATORapplications.line and load variation) beside to ensure a con-Operating with a input voltage from 3V ..
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LBC846BLT1G , General Purpose Transistors NPN Silicon
L4957AD-1.8-L4957AV15
UP TO 5A ULDO LINEAR REGULATOR
L4957A TO 5A ULDO LINEAR REGULATOR
PRODUCT PREVIEW1.5V, 1.8V, 2.5V AND 3.3V FIXED OUTPUT
VOLTAGE TO 14V INPUT VOLTAGERANGE
200mΩ Rdson TYPICAL @Tj= 125°C
0.6V max. DROP-OUT AT 2A
EXCELLENTLOAD REGULATION
0.6mAQUIESCENT CURRENT AT ANYLOAD
SHORT CIRCUIT PROTECTION
THERMAL SHUTDOWN
APPLICATIONSMOTHER BOARDS
PROCESSOR I/O& SUPPLIES
LOW VOLTAGE MEMORY& CHIP SET SUP-
PLIES
GRAPHIC& SOUND CARDS
LOW VOLTAGE LOGIC SUPPLIES
POST REGULATOR FOR SMPS
DESCRIPTIONThe L4957A devices are
Ultra Low Drop Outputlinear regulators with an internal N-channel MOS 200mΩ particulary suitable for low voltage/low
dropout applications.
Operating witha input voltage from 3Vto 14V
they are capableto deliverupto 5A.
The devices are ideal for useas oneof the sup-
plies requiredby processor,for example they are
the cost effective and efficient solutionfor conver-
sion from 3.3V (rail bus)to 2.5V @ 2.5Aorto
1.5V with high current rating.
Fast response transient minimise the output ca-
pacitor value.A minimumof 22μF assures the
stabilityinall load conditions.
The on-chip trimming technique offersa tighter
voltage reference tolerance (with± 2% including
line and load variation) besideto ensurea con-
trolled short circuit current. Thermal shutdown
provides protection against overload conditions
that creates excessive junction temperature.
L4957A
GND
OUTINto 14V
VOUT
D00IN1107A
TYPICAL APPLICATION
ORDERING NUMBERS:
L4957AV1.5 L4957AD1.5
L4957AV1.8 L4957AD1.8
L4957AV2.5 L4957AD2.5
L4957AV3.3 L4957AD3.3
MULTIPOWER BCD TECHNOLOGY
2
PAKVersawatt TO-220
ABSOLUTE MAXIMUM RATINGS
Symbol Parameter Value Unit
VIN Supply Input Voltage 16 V Junction Temperature -40to +150 °C
Tstg Storage Temperature -40to +150 °C
PINS CONNECTION
PRE
REGULATOR
VREF
E/A
OUT
GND
D00IN1108A
VIN
10μF
CURRENT
LIMIT
THERMAL
SHUTDOWN
BUFFER
CHARGE
PUMP
POWER
DMOS
200mΩ
22μF
VOUT
BLOCK DIAGRAM
OUT
GND1
D98IN838B
Versawatt (TO220)
OUT
GND1
D98IN933A
D2PAK
PIN FUNCTIONS
PinN° Name Function IN Unregulated input voltage; thispin mustbe bypassed with acapacitor larger than 10μF. GND To connectto Groundtoget 1.5V, 1.8V, 2.5Vor 3.3V output. OUT Regulated output voltage.A minimum bypass capacitorof 22μFis requiredto insure stability.
L4957A
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 Supply Voltage 3 14 V Output Voltage 3.15VVIN= 3.3V ±5%; 0.1AVIN= 3.3V ±5% IO= 0.1A
VIN =5V ±5%
1.782 1.8 1.818 V
VIN= 3.3V ±5% (0.1AVIN =5V ±5% 0.1AVIN= 3.3V ±5% IO= 0.1A
VIN =5V ±5%
2.475 2.5 2.525 V
VIN= 3.3V ±5% (0.1AVIN =5V ±5% 0.1AVIN =5V ±5% IO= 0.1A 3.267 3.3 3.333 V
VIN =5V ±5% 0.1ARDSON Drain-Source ON
Resistance • 300 mΩ Current Limiting • 5.1 6.3 7.5 A Quiescent Current 3VRipple Rejection f= 120Hz,IO =1A
VIN =5V ΔVIN =2VPP 75 dB
THERMAL DATA
Symbol Parameter TO220 D2PAK Unit
Rth j-case Thermal Resistance Junction-case Max. 2.5 3 °C/W
Rth j-amb Thermal Resistance Junction-ambient Max. 50 60 °C/W
Thermal Shutdown Typ. 150 °C
Thermal Hysteresis Typ. 20 °C
-40 -20 0 20 40 60 80 100 120 140 1600
Tj[°C]
Output
Voltage
Deviation
[mV]Iout= 10mA
Figure1: Line Regulation vs. Junction
Temperature
Iout[A]
Output
Voltage
Deviation
[mV]
Vin=5V =25°C
(Pulsed techniquehas been used)
Vout= 1.5V
Figure2: Load Regulation
L4957A
*Pulsed tecniquehas been used
-40 -20 0 20406080 100 120 140 1600 [°C]
Output Current [A]
(Vin-Vout)>2V
pin2= GND
Figure3: Maximum OutputCurrentvs. Junction
Temperature
Vin>2.8V
Tj=125C Tc=25°C
Pdmax=40W
Rdson
limit Operating Area
Power Dissipation Limit
Current Limitation
Tc=70°C
Pdmax=22W 12345 678
(Vin- Vout) [V]
Output Current [A]
Figure4: DC OperatingArea
100 requ ency [Hz]
Ripple Rejec tion [dB]10 100 10k 100k
Vripple=3Vp-p Vripple=0.5 Vp-p in=22uF
Cou t=22uF
Vout=1.5V
Vin min=3Vut=5A
Figure5: Ripple Rejection vs. Frequency
6.3 IOUT(A)
VOUT
(V)
D00IN1109
Figure6: Output Voltage vs. Output Current.
(VOUT= 1.5V) 0.2 0.4 0.6 0.81 1.2 1.4 1.6 1.820
4.5 [A]a ximum Ron limits= 100°C=1 25°C= 25°C
Figure7: Maximum OutputCurrent vs. Drop-Out
Voltage
L4957A
Versawatt (TO220)
DIM. mm inch
MIN. TYP. MAX. MIN. TYP. MAX. 4.40 4.60 0.173 0.181 1.23 1.32 0.048 0.051 2.40 2.72 0.094 0.107 0.49 0.70 0.019 0.027 0.61 0.88 0.024 0.034 1.14 1.70 0.044 0.067 1.14 1.70 0.044 0.067 4.95 5.15 0.194 0.203 2.40 2.70 0.094 0.106 10.0 10.4 0.393 0.409 16.4 0.645 13.0 14.0 0.511 0.551 2.65 2.95 0.104 0.116 15.25 15.75 0.600 0.620 6.20 6.60 0.244 0.260 3.50 3.93 0.137 0.154 2.6 0.102
Dia 3.75 3.85 0.147 0.151
TO220MEC
OUTLINE AND
MECHANICAL DATA
L4957A
2 PAKOUTLINE AND
MECHANICAL DATA
2.0 MIN.
FLATZONE
REF.
DIMENSIONS
Millimeters Inches
Min. Typ. Max. Min. Typ. Max. 4.30 4.60 0.169 0.181 2.49 2.69 0.098 0.106 0.03 0.23 0.001 0.009 0.70 0.93 0.027 0.037 1.25 1.40 0.049 0.055 0.45 0.60 0.017 0.024 1.21 1.36 0.047 0.054 8.95 9.35 0.352 0.368 10.00 10.28 0.393 0.405 4.88 5.28 0.192 0.208 15.00 15.85 0.590 0.624 1.27 1.40 0.050 0.055 1.40 1.75 0.055 0.069 0.40 0.016 0° 8° 0° 8°
L4957A
