L4957A STMICROELECTRONICS | Alldatasheet

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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 200m Ω Rdson TYPICAL @ T j= 125°C 0.6V max. DROP-OUT AT 2A EXCELLENT LOAD REGULATION 0.6mAQUIESCENT CURRENT AT ANY LOAD SHORT CIRCUIT PROTECTION THERMAL SHUTDOWN

APPLICATIONS

PROCESSOR I/O & SUPPLIES LOW VOLTAGE MEMORY & CHIP SET SUP- PLIES GRAPHIC & SOUND CARDS LOW VOLTAGE LOGIC SUPPLIES POST REGULATOR FOR SMPS

DESCRIPTION

The L4957A devices areUltraLow D rop O utput 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- 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. This is preliminary information on a new product now in development. Details are subject to change without notice. May 2000 L4957A GND OUTIN 3V to 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 D 2PAKVersawatt TO-220

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 IN PRE REGULATOR VREF E/A OUT GND D00IN1108A VIN 10µF CURRENT LIMIT THERMAL SHUTDOWN BUFFER CHARGE PUMP POWER DMOS 200m Ω 22µF VOUT R Y R X BLOCK DIAGRAM OUT GND IN1 D98IN838B Versawatt (TO220) OUT GND IN1 D98IN933A D2PAK PIN FUNCTIONS Pin N° Name Function 1 IN Unregulated input voltage; this pin must be bypassed with a capacitor larger than 10µF. 3 OUT Regulated output voltage. A minimum bypass capacitor of 22µF is required to insure stability. L4957A

*Pulsed tecnique has been used - 4 0 - 2 0 0 2 04 06 08 0 1 0 0 1 2 0 1 4 0 1 6 0 Tj [°C] Output Current [A] (Vin-Vout) > 2V pin 2 = GND Figure 3:Maximum Output Currentvs. Junction Temperature Vin>2.8 V Tj=1 25C Tc=25 °C Pdmax= 40 W Rdson limit D C Operating Area P owe r D is s ipation Lim it Current Lim itation Tc = 70°C Pdmax =2 2 W 012345678 (Vin - Vout) [V] Output Current [A] Figure 4:DC Operating Area 100 Frequency [Hz] Ri ppl e Rej e ct i on [ dB] 1k10 100 10k 100k Vripple=3V p-p Vripple=0.5Vp-p Ci n=22uF Cout = 22uF Vout=1.5V Vinmin=3V Io ut= 5A Figure 5:Ripple Rejection vs. Frequency

6.3 IOUT (A)

(V) D00IN1109 Figure 6:Output Voltage vs. Output Current. (VOUT = 1.5V) 0.5 1.5 2.5 3.5 4.5 Δ V=V i n-V o Io [A] maximum Ron limits Tj = 100 °C Tj = 125 °C Tj = 25°C Figure 7:Maximum Output Current vs. Drop-Out Voltage L4957A

Versawatt (TO220) DIM. mm inch A 4.40 4.60 0.173 0.181 C 1.23 1.32 0.048 0.051 D 2.40 2.72 0.094 0.107 E 0.49 0.70 0.019 0.027 F 0.61 0.88 0.024 0.034 F1 1.14 1.70 0.044 0.067 F2 1.14 1.70 0.044 0.067 G 4.95 5.15 0.194 0.203 G1 2.40 2.70 0.094 0.106 H2 10.0 10.4 0.393 0.409 L2 16.4 0.645 L4 13.0 14.0 0.511 0.551 L5 2.65 2.95 0.104 0.11 L6 15.25 15.75 0.600 0.620 L7 6.20 6.60 0.244 0.260 L9 3.50 3.93 0.137 0.154 M 2.6 0.102 Dia 3.75 3.85 0.147 0.151 M TO220MEC OUTLINE AND MECHANICAL DATA L4957A

A D R 2.0 MIN. FLAT ZONE C G L B E 8.90 3.70 1.30 5.08 16.90 10.30 REF. DIMENSIONS Millimeters Inches A 4.30 4.60 0.169 0.181 A1 2.49 2.69 0.098 0.106 A2 0.03 0.23 0.001 0.009 B 0.70 0.93 0.027 0.037 B2 1.25 1.40 0.049 0.055 C 0.45 0.60 0.017 0.024 C2 1.21 1.36 0.047 0.054 D 8.95 9.35 0.352 0.368 E 10.00 10.28 0.393 0.405 G 4.88 5.28 0.192 0.208 L 15.00 15.85 0.590 0.624 L2 1.27 1.40 0.050 0.055 L3 1.40 1.75 0.055 0.069 R 0.40 0.016 V2 0 ° 8° 0° 8° L4957A

Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specification mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics. The ST logo is a registered trademark of STMicroelectronics  2000 STMicroelectronics – Printed in Italy – All Rights Reserved STMicroelectronics GROUP OF COMPANIES Australia - Brazil - China - Finland - France - Germany - Hong Kong - India - Italy - Japan - Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - U.S.A. http://www.st.com L4957A