ULDO LINEAR REGULATOR OUTPUT CURRENT 6.5V INPUT VOLTAGE RANGE OUT

The Datasheet Archive - 100 Million Datasheets from 7500 Manufacturers.

ULDO LINEAR REGULATOR OUTPUT CURRENT 6.5V INPUT VOLTAGE RANGE OUT

Datasheet Thumbnail

Top Searches for this datasheet

L4957
ULDO LINEAR REGULATOR
OUTPUT CURRENT 6.5V INPUT VOLTAGE RANGE OUTPUT VOLTAGE ADJUSTABLE FROM 1.26V 150m (TYP) Rdson EXCELLENT LOAD REGULATION 0.8mA QUIESCENT CURRENT SHORT CIRCUIT PROTECTION THERMAL SHUTDOWN APPLICATIONS PENTIUMFAMILY POWER PCSUPPLIES COST SOLUTION 3.3V 1.5V CONVERSION POST REGULATOR SMPS
MULTIPOWER TECHNOLOGY
VERSAWATT (TO-220)
DESCRIPTION L4957 Ultra Drop Output three terminal adjustable regulator with minimum output voltage 1.26V. device ideal supplies required processor, thanks internal
channel with Rdson 150m local conversion from 3.3V 1.5V with high current rating achievable. on-chip trimming tecnique inprove precision output voltage beside ensure controlled short circuit current. On-chip thermal shutdown provides protection against overload conditions that creates excessive junction temperature.
TYPICAL APPLICATIONS
3.3V
VOUT>1.26V/5A
L4957
D97IN657B
March 1998
This preliminary information product development undergoing evaluation.
L4957
ABSOLUTE MAXIMUM RATINGS
Symbol PTOT Tst, Parameter Supply Input Voltage Power Dissipation Tamb 50°C Power Dissipation Tcase 90°C Storage Temperature Value +150 Unit
CONNECTION (Top view)
D98IN838
BLOCK DIAGRAM
10µF
VREF= 1.26V CURRENT LIMIT WITH FOLDBACK CHARGE PUMP
REGULATOR
BUFFER
POWER DMOS 150m VOUT 22µF
THERMAL SHUTDOWN
D98IN839
L4957
FUNCTIONS
Name Function Unregulated input voltage; this must bypassed with capacitor larger than 10µF. connect 1.26V output. connect external divider output adjustable voltages. Regulated output voltage. minimum bypass capacitor 22µF required insure stability.
THERMAL DATA
Symbol j-case j-amb Parameter Thermal Resistance Junction-case Thermal Resistance Junction-ambient Thermal Shutdown Thermal Hysteresis Max. Max. Typ. Typ. Value Unit °C/W °C/W
L4957 ELECTRICAL CHARACTERISTICS 25°C, unless otherwise specified). Specifications referred from +125°C.
Symbol Parameter Operating Supply Voltage Output Voltage Load regulation Dropout Voltage Test Condition 0.1A <6.5V 6.5V; 0.1A 0.1A Current Limiting Short Circuit Current Quiescent Current Ripple Rejection 0.1A 120Hz, 2VPP Min. Typ. 1.26 1.26 0.75 0.55 Max. 1.285 1.298 0.75 Unit
1.235 1.222
connected ground.
Figure Output Voltage Stability Junction Temperature
Vout 1.28 1.275 1.27 1.265 1.26 1.255 1.25 1.245 1.24 [°C]
Iout 10mA
Figure Line Regulation Junction Temperature
Output Voltage Deviation [mV] [°C]
6.5V Iout 10mA
L4957
Figure Load Regulation
Output Voltage Deviation [mV] Iout
Figure Dropout Voltage
(Pulsed technique been used)
Vout 1.26V
Figure Maximum Output Current Junction Temperature with internal current limiting
utput Current (Vin-Vout)
Figure Operating Area
dson Power ax=40
*Pulsed tecnique been used
Figure Ripple Rejection Frequency
Ripple Rejection [dB]
22uF Cout 22uF Vout 1.26V Vinmin Iout Vripple 3Vp-p Vripple 0.5Vp-p
Figure Output Voltage Output Current.
VOUT
D98IN846
VOUT
Frequency [Hz]
100k
IOUT(A)
L4957
OUTPUT VOLTAGE Figure
Vref
VOUT
L4957
D98IN841
output voltage Vout given Vout Vref R2/R1) Vref where current through quiescent current Fixing have chosen Vref/Ia (Vout Vref) Choosing current 10mA, following table shows output voltage, Vout, accuracy, over load regulation taking Vref spread into account. Table been obtained range 0.5mA ±30%, assuming accuracy Figure
Table Vout selection.
22.6 60.4 88.7 Vout ±2.5% ±3.1% ±3.4% ±3.6% ±4.0% ±4.6%
good regulation resistor divider connected between terminal output should connected directly output regulator rather than near load. fact line resistance, series output, output voltage will Vout Vref R2/R1) IqR2 Iout
WORSE
IOUT VOUT
BETTER VREF
IOUT VOUT
L4957
VREF
L4957
D98IN842
D98IN843
resistor divider connected near load effective line resistance will R2/R1) fact Vout given
Vout (Vref Iout) R2/R1) with load regulation Iout R2/R1) which worse than other case.
L4957
VERSAWATT (TO220) PACKAGE MECHANICAL DATA
DIM. MIN. 26.3 15.1 3.65 10.05 16.2 26.7 27.1 15.8 3.85 1.035 0.102 0.594 0.236 0.144 0.35 1.15 4.95 5.08 TYP. MAX. 1.37 1.35 0.55 1.05 5.21 10.4 10.4 0.396 0.638 1.051 1.067 0.118 0.622 0.260 0.152 0.094 0.047 0.014 0.031 0.045 0.195 0.200 MIN. inch TYP. MAX. 0.189 0.054 0.110 0.053 0.022 0.041 0.055 0.205 0.409 0.409
Dia.
TO220MEC
L4957
Information furnished believed accurate reliable. However, SGS-THOMSON Microelectronics assumes responsibility consequences such information infringement patents other rights third parties which result from use. license granted implication otherwise under patent patent rights SGS-THOMSON Microelectronics. Specification mentioned this publication subject change without notice. This publication supersedes replaces information previously supplied. SGSTHOMSON Microelectronics products authorized critical components life support devices systems without express written approval SGS-THOMSON Microelectronics. 1998 SGS-THOMSON Microelectronics Printed Italy Rights Reserved SGS-THOMSON Microelectronics GROUP COMPANIES Australia Brazil Canada China France Germany Hong Kong Italy Japan Korea Malaysia Malta Morocco Netherlands Singapore Spain Sweden Switzerland Taiwan Thailand United Kingdom U.S.A.

ULDO LINEAR REGULATOR OUTPUT CURRENT 6.5V INPUT VOLTAGE RANGE OUT

Top Searches for this datasheet

Other recent searches