SGS Thomson Microelectronics L4957AV3.3, L4957AV2.5, L4957AV1.8, L4957AV1.5, L4957AD2.5 Datasheet
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L4957A |
UP TO 5A ULDO LINEAR REGULATOR
PRODUCT PREVIEW
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
0.6mAQUIESCENT CURRENT AT ANY LOAD SHORT CIRCUIT PROTECTION
THERMAL SHUTDOWN
MULTIPOWER BCD TECHNOLOGY
3
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1 |
Versawatt TO-220 |
D2PAK |
ORDERING NUMBERS:
APPLICATIONS
MOTHER BOARDS PROCESSOR I/O & SUPPLIES
LOW VOLTAGE MEMORY & CHIP SET SUPPLIES
GRAPHIC & SOUND CARDS LOW VOLTAGE LOGIC SUPPLIES POST REGULATOR FOR SMPS
DESCRIPTION
The L4957A devices are Ultra Low Drop Output linear 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-
TYPICAL APPLICATION
L4957AV1.5 |
L4957AD1.5 |
L4957AV1.8 |
L4957AD1.8 |
L4957AV2.5 |
L4957AD2.5 |
L4957AV3.3 |
L4957AD3.3 |
plies required by processor, for example they are the cost effective and efficient solution for conversion from 3.3V (rail bus) to 2.5V @ 2.5A or to 1.5V with high current rating.
Fast response transient minimise the output capacitor 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 controlled short circuit current. Thermal shutdown provides protection against overload conditions that creates excessive junction temperature.
3V to 14V IN |
OUT |
VOUT |
1 |
3 |
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L4957A |
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C1 |
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C2 |
2
GND
D00IN1107A
May 2000 |
1/7 |
This is preliminary information on a new product now in development. Details are subject to change without notice.
L4957A
ABSOLUTE MAXIMUM RATINGS
Symbol |
Parameter |
Value |
Unit |
VIN |
Supply Input Voltage |
16 |
V |
Ti |
Junction Temperature |
-40 to +150 |
°C |
Tstg |
Storage Temperature |
-40 to +150 |
°C |
PINS CONNECTION
3 |
OUT |
3 |
OUT |
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2 |
GND |
2 |
GND |
1 |
IN |
1 |
IN |
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D98IN838B |
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D98IN933A |
Versawatt (TO220) |
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D2PAK |
BLOCK DIAGRAM
IN
VIN |
1 |
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10μF |
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CURRENT |
CHARGE |
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VREF |
PUMP |
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LIMIT |
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PRE |
+ |
BUFFER |
POWER |
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E/A |
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DMOS |
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REGULATOR |
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- |
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200mΩ |
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THERMAL |
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OUT |
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VOUT |
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SHUTDOWN |
3 |
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RX |
22μF |
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RY |
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2 |
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GND |
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D00IN1108A |
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PIN FUNCTIONS
Pin N° |
Name |
Function |
1 |
IN |
Unregulated input voltage; this pin must be bypassed with a capacitor larger than 10μF. |
2 |
GND |
To connect to Ground to get 1.5V, 1.8V, 2.5V or 3.3V output. |
3 |
OUT |
Regulated output voltage. A minimum bypass capacitor of 22μF is required to insure stability. |
2/7
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L4957A |
THERMAL DATA |
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Symbol |
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Parameter |
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TO220 |
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D2PAK |
Unit |
Rth j-case |
Thermal Resistance Junction-case |
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Max. |
2.5 |
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3 |
°C/W |
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Rth j-amb |
Thermal Resistance Junction-ambient |
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Max. |
50 |
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60 |
°C/W |
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Thermal Shutdown |
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Typ. |
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150 |
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°C |
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Thermal Hysteresis |
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Typ. |
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20 |
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°C |
ELECTRICAL CHARACTERISTICS (Tj = 25°C, VIN = 5V, unless otherwise specified). |
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•= Specifications referred to TJ from 0°C to +125°C. |
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Symbol |
Parameter |
Test Condition |
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Min. |
Typ. |
Max. |
Unit |
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VIN |
Operating Supply Voltage |
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3 |
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14 |
V |
VO |
Output Voltage |
3.15V < VIN < 5.25V; IO = 0.1A |
• |
1.485 |
1.5 |
1.515 |
V |
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VIN = 3.3V ±5%; 0.1A < IO < 5A |
1.47 |
1.5 |
1.53 |
V |
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VIN = 3.3V ±5% |
IO = 0.1A |
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1.782 |
1.8 |
1.818 |
V |
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VIN = 5V ±5% |
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• |
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VIN = 3.3V ±5% |
(0.1A < IO < 45A) |
1.764 |
1.8 |
1.836 |
V |
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VIN = 5V ±5% |
0.1A < IO < 5A |
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VIN = 3.3V ±5% |
IO = 0.1A |
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2.475 |
2.5 |
2.525 |
V |
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VIN = 5V ±5% |
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• |
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VIN = 3.3V ±5% (0.1A < IO < 2.2A) |
2.45 |
2.5 |
2.55 |
V |
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VIN = 5V ±5% |
0.1A < IO < 5A |
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VIN = 5V ±5% |
IO = 0.1A |
• |
3.267 |
3.3 |
3.333 |
V |
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VIN = 5V ±5% |
0.1A < IO < 5A |
3.234 |
3.3 |
3.366 |
V |
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RDSON |
Drain-Source ON |
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• |
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300 |
mΩ |
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Resistance |
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• |
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IO |
Current Limiting |
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5.1 |
6.3 |
7.5 |
A |
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IQ |
Quiescent Current |
3V < VIN < 14V |
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• |
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0.6 |
2 |
mA |
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Ripple Rejection |
f = 120Hz, IO = 1A |
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60 |
75 |
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dB |
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VIN = 5V VIN = 2VPP |
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Figure 1: Line Regulation vs. Junction Temperature
[mV] |
5 |
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4.5 |
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Deviation |
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3.5 |
3V < Vin < 6.5V |
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4 |
Iout = 10mA |
Voltage |
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3 |
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Output |
2.5 |
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2 |
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1.5 |
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1 |
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0.5
0 -40 -20 0 20 40 60 80 100 120 140 160
Tj [°C]
Figure 2: Load Regulation
[mV] |
5 |
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4 |
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Deviation |
Vin = 5V |
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3 |
Tj = 25 °C |
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(Pulsed technique has been used) |
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Voltage |
2 |
Vout = 1.5V |
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1 |
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Output |
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0 |
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-1 -2 -3 -4
-5
0 |
1 |
2 |
3 |
4 |
5 |
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Iout [A] |
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3/7
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