L4957AD1.8TR ,UP TO 5A ULTRA LOW DROP OUPUT LINEAR REGULATORBLOCK DIAGRAMINVIN110m FCHARGECURRENTPUMPVREFLIMIT+ BUFFER POWERPREE/ADMOSREGULATOR-200mWOUTTHERMAL ..
L4957AD-1.8TR ,UP TO 5A ULTRA LOW DROP OUPUT LINEAR REGULATORapplications. trolled short circuit current. Thermal shutdownprovides protection against overload c ..
L4957AD2.5 ,UP TO 5A ULTRA LOW DROP OUPUT LINEAR REGULATORABSOLUTE MAXIMUM RATINGSSymbol Parameter Value UnitV Supply Input Voltage 16 VINT Junction Temperat ..
L4957AD25TR ,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 ..
L4957AD3.3 ,UP TO 5A ULTRA LOW DROP OUPUT LINEAR REGULATORAPPLICATIONSL4957AV1.5 L4957AD1.5L4957AV1.8 L4957AD1.8M ..
L4957AD3.3TR ,UP TO 5A ULTRA LOW DROP OUPUT LINEAR REGULATORABSOLUTE MAXIMUM RATINGSSymbol Parameter Value UnitV Supply Input Voltage 16 VINT Junction Temperat ..
LBC2518T1R0M , WOUND CHIP INDUCTORS
LBC2518T1R0M , WOUND CHIP INDUCTORS
LBC2518T3R3M , WOUND CHIP INDUCTORS
LBC2518T4R7M , WOUND CHIP INDUCTORS
LBC2518T4R7M , WOUND CHIP INDUCTORS
LBC807-25LT1G , General Purpose Transistors PNP Silicon
L4957AD1.5TR-L4957AD1.8TR-L4957AD-1.8TR-L4957AD25TR-L4957AD3.3TR
UP TO 5A ULTRA LOW DROP OUPUT LINEAR REGULATOR
L4957AUP TO 5A ULDO LINEAR REGULATOR
1.5V, 1.8V, 2.5V AND 3.3V FIXED OUTPUT
VOLTAGE
3V TO 14V INPUT VOLTAGE RANGE
200mΩ Rdson TYPICAL @ Tj = 125°C
0.6V max. DROP-OUT AT 2A
EXCELLENT LOAD REGULATION
0.6mA QUIESCENT CURRENT AT ANY LOAD
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
of 200mΩ particulary suitable for low voltage/low
dropout applications.
Operating with a input voltage from 3V to 14V
they are capable to deliver up to 5A.
The devices are ideal for use as one of the sup-
plies required by processor, for example they are
the cost effective and efficient solution for conver-
sion from 3.3V (rail bus) to 2.5V @ 2.5A or to
1.5V with high current rating.
Fast response transient minimise the output ca-
pacitor value. A minimum of 22μF assures the
stability in all load conditions.
The on-chip trimming technique offers a tighter
voltage reference tolerance (with ± 2% including
line and load variation) beside to ensure a con-
trolled short circuit current. Thermal shutdown
provides protection against overload conditions
that creates excessive junction temperature.
TYPICAL APPLICATION
ABSOLUTE MAXIMUM RATINGS
PINS CONNECTION
BLOCK DIAGRAM
PIN FUNCTIONS
L4957A2/7
ELECTRICAL CHARACTERISTICS (Tj = 25°C, VIN = 5V, unless otherwise specified).• = Specifications referred to TJ from 0°C to +125°C.
THERMAL DATA-40 -20 0 20 40 60 80 100 120 140 1600
t V
eviat
Figure 1: Line Regulation vs. Junction
Temperature 2345-5
Iout [A]
t V
lta
tio
[m
Figure 2: Load Regulation
L4957A3/7
*Pulsed tecnique has been used
-40 -20 0 20 40 60 80 100 120 140 1600
Tj [°C]
Output Current [A]
Figure 3: Maximum Output Current vs. JunctionTemperature 234 567 8
(Vin - Vout) [V] utput Current [A]
Figure 4: DC Operating AreaRipple R ejection [dB] 10 100
Figure 5: Ripple Rejection vs. Frequency6.3 IOUT(A)
VOUT
D00IN1109
Figure 6: Output Voltage vs. Output Current. 0.2 0.4 0.6 0.81 1.2 1.4 1.6 1.820
ΔV = Vin - Vo [A]
Figure 7: Maximum Output Current vs. Drop-OutVoltage
L4957A4/7
L4957A5/7
L4957A6/7
