L4957 UP TO 4A ULDO LINEAR REGULATOR 1.5V AND 2.5V FIXED OUTPUT VOLTAGE 3V TO 6.5V 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 WITH FOLDBACK THERMAL SHUTDOWN MULTIPOWER BCD TECHNOLOGY 3 1 Versawatt TO-220 APPLICATIONS D2PAK ORDERING NUMBERS: 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 L4957 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 6.5V they are capable to deliver up to 4A at 1.5V or 2.5V fixed output voltages. L4957V1.5 L4957V2.5 L4957D1.5 L4957D2.5 The devices are ideal for use as one of the supplies 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. TYPICAL APPLICATION 3V to 6.5V IN 1 3 OUT VOUT=1.5V/2.5V L4957 C1 C2 2 GND D97IN657E February 2000 1/7 L4957 ABSOLUTE MAXIMUM RATINGS Symbol Parameter Value Unit VIN Supply Input Voltage 7 V Ti Junction Temperature -40 to +150 °C Tstg Storage Temperature -40 to +150 °C PINS CONNECTION 3 OUT 3 2 GND 2 IN 1 1 OUT GND IN D98IN838B D98IN933A Versawatt (TO220) D2PAK BLOCK DIAGRAM VIN 10µF IN 1 CURRENT LIMIT WITH FOLDBACK VREF PRE REGULATOR + - E/A CHARGE PUMP BUFFER POWER DMOS 150mΩ OUT THERMAL SHUTDOWN RX 3 22µF RY 2 GND D98IN839C 2/7 VOUT L4957 PIN FUNCTIONS Pin N° Name Function 1 IN 2 GND To connect to Ground to get 1.5V or 2.5V output. 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. THERMAL DATA Symbol TO220 D2PAK Unit Rth j-case Thermal Resistance Junction-case Parameter 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 L4957 - ELECTRICAL CHARACTERISTICS (Tj = 25°C, VIN = 5V, unless otherwise specified). • = Specifications referred to TJ from 0°C to +125°C. Symbol Parameter VIN Operating Supply Voltage (1) VO Output Voltage (1) ∆V O R DSON Test Condition Load regulation (1) Min. IQ Max. Unit 6.5 V For L4957V1.5/D1.5 0.1A < IO < 4A; 3V < VIN < 6.5V 3V < VIN < 6.5V; 0.1A < IO < 4A • 1.47 1.455 1.5 1.5 1.53 1.545 V V For L4957V2.5/D2.5 0.1A < IO < 4A; 3V < VIN < 6.5V 3V < VIN < 6.5V; 0.1A < IO < 4A • 2.45 2.425 2.5 2.5 2.55 2.575 V V 0.1A < IO < 4A • Drain-Source ON Resistance IO Typ. 3 Current Limiting 90% VO Short Circuit Current VO = 0V Quiescent Current 0.1A < IO < 4A 3V < VIN < 6.5V Ripple Rejection f = 120Hz, IO = 4A VIN = 5V ∆VIN = 2VPP • • • 5.1 2 10 mV 200 300 mΩ 6.3 7.5 A 1.8 A 0.5 2 60 mA 75 dB (1) GND connected to ground. 5 4.5 3V < Vin < 6.5V Iout = 10mA 4 3.5 3 2.5 5 4 Vin = 5V Tj = 25 °C (Pulsed technique has been used) 3 Vout = 1.5V 2 1 0 -1 2 -2 1.5 -3 1 -4 0.5 0 -40 Figure 2: Load Regulation Output Voltage Deviation [mV] Output Voltage Deviation [mV] Figure 1: Line Regulation vs. Junction Temperature -5 -20 0 20 40 60 80 Tj [°C] 100 120 140 160 0 1 2 3 4 5 Iout [A] 3/7 L4957 Figure 3: Maximum Output Current vs. Junction Temperature Figure 4: DC Operating Area O utput C urrent [A] 10 O u t p u t C u r r en t [ A ] 8 9 V in > 2 .8V T j= 1 2 5C 7 6 7 6 5 5 4 4 P ow er D is s ip ation Lim it R d s on lim it Tc = 70 °C P d m a x =2 2 W 3 (Vin-Vout) > 2V pin 2 = G ND 3 Tc =2 5 °C P dm a x = 40 W C u rre nt L im ita tio n 8 D C O p e ratin g A re a 2 2 1 1 0 -40 -20 0 20 40 60 80 100 120 140 160 Tj [°C] 0 0 1 2 *P ulsed tecnique ha s been used Figure 5: Ripple Rejection vs. Frequency 6 7 Figure 6: Output Voltage vs. Output Current. (VOUT = 1.5V) R ip p le R e je c t i o n [ d B ] VOUT (V) 10 0 90 3 4 5 ( Vi n - Vo u t ) [ V ] D98IN846A V rip p l e = 3 V p -p V r ipp l e = 0 .5 V p - p 80 70 60 50 40 80% VOUT C i n = 2 2u F C o u t= 2 2 u F V o u t= 1 . 5 V V i n m in = 3 V Io u t= 5 A 30 20 10 0 10 10 0 1k F re q u e n c y [H z ] 10 k 100k Figure 7: Maximum Output Current vs. Drop-Out Voltage Io [A ] 5 4 .5 T j = 2 5 °C 4 T j = 1 2 5 °C 3 .5 T j = 1 0 0 °C 3 2 .5 2 1 .5 1 m a x im u m R o n lim its 0 .5 0 4/7 0 0 .2 0 .4 0 .6 0 .8 1 1 .2 1 .4 1 .6 1 .8 2 ∆ V = V in - Vo 1.8 6.3 IOUT(A) 8 L4957 mm MIN. TYP. inch MAX. MIN. TYP. MAX. 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 0.116 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 Dia 2.6 3.75 OUTLINE AND MECHANICAL DATA 0.102 3.85 0.147 Versawatt (TO220) 0.151 M DIM. TO220MEC 5/7 L4957 DIMENSIONS REF. Millimeters OUTLINE AND MECHANICAL DATA Inches Min. Typ. Max. Min. Typ. Max. 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 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 1.40 0.049 0.055 0.40 V2 0° D2PAK 0.016 8° 0° 8° A E C2 L2 16.90 D L L3 10.30 A1 5.08 1.30 B2 B R C 3.70 8.90 G A2 2.0 MIN. FLAT ZONE V2 6/7 L4957 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. 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