LX8554-00CDD

LIN D O C #: 8554 LX8554-xx 5A E XTREMELY L OW D ROPOUT P OSITIVE R EGULATORS T H E I N F I N I T E P O W E R I O F P N N O VA T I O N DESCRIPTION The LX8554 series ICs are very low dropout three-terminal positive regulators with 5A rated output current. This product family is ideally suited for Pentium® Processor and Power PCTM applications requiring fast transient response. The LX8554 is guaranteed to have a dropout voltage under 1V at 5A load, making it ideal to provide well-regulated outputs of 2.5V to 3.6V with input supply as low as 4.75V. Fixed versions are also available and are specified in the Available Options table below. Current limit is trimmed above 5.1A to ensure adequate output current and con- LX8554 OUT ADJ VREF 1500µF, 6.3V Sanyo MVGX Series R1 121W 1% 200W 1% R2 JP1 Open Open Short 13W 1% JP1 14.7W 1% JP2 JP2 Open Short Short S H E E T ■ THREE-TERMINAL ADJUSTABLE OR FIXED OUTPUT ■ GUARANTEED ≤ 1V HEADROOM AT 5A ■ OUTPUT CURRENT OF 5A p FAST TRANSIENT RESPONSE p 1% VOLTAGE REFERENCE INITIAL ACCURACY p OUTPUT SHORT-CIRCUIT PROTECTION p BUILT-IN THERMAL SHUTDOWN ■ EVALUATION BOARD AVAILABLE: REQUEST LXE9001 EVALUATION KIT trolled short-circuit current. On-chip thermal limiting provides protection against any combination of overload that would create excessive junction temperatures. The LX8554 series products are available in both through-hole and surfacemount versions of industry standard 3-pin TO-220 / TO-263 power packages. The LX8554 family of products are ideal for use in multiple processor applications where output voltage is jumper selected. The LX8554 ICs offer precision output as well as low supply operation (see application below). For higher current applications see the LX8584 series of products. A P P L I C AT I O N S ■ ■ ■ ■ ■ ■ TYPICAL APPLICATION OF THE LX8554 IN A FLEXIBLE MOTHERBOARD WITH OUTPUT VOLTAGE SELECTABLE VIA JUMPERS "JP1" AND "JP2" IN A T A K E Y F E AT U R E S PRODUCT HIGHLIGHT VIN ³ 4.75 D R O D U C T I O N VO PENTIUM PROCESSOR SUPPLIES POWER PC SUPPLIES MICROPROCESSOR SUPPLIES LOW VOLTAGE LOGIC SUPPLIES BATTERY POWERED CIRCUIT POST REGULATOR FOR SWITCHING SUPPLY A VA I L A B L E O P T I O N S (See Table Below) 3x 1500µF 6.3V Sanyo MVGX Series Part # LX8554-00 LX8554-33 PER PAR T # Output Voltage Adjustable 3.3V Other voltage options may be available — Please contact factory for details. VOUT = VREF 1 + R2 + IADJ R2 R1 OUTPUT VOLTAGE 3.6V 3.45V 3.3V PA C K A G E O R D E R I N F O R M AT I O N TA (°C) 0 to 125 TO-220 P Plastic 3-pin T0-263 DD Plastic 3-pin LX8554-xxCP LX8554-xxCDD Note: All surface-mount packages are available in Tape & Reel. Append the letter "T" to part number. (i.e. LX8554-00CDDT) "xx" refers to output voltage, please see table above. F O R F U R T H E R I N F O R M AT I O N C A L L ( 7 1 4 ) 8 9 8 - 8 1 2 1 Copyright © 1997 Rev. 1.1 1/97 11861 WESTERN A VENUE , G ARDEN G ROVE , CA. 92841 1 PRODUCT DATABOOK 1996/1997 LX8554-xx 5A E XTREMELY L OW D ROPOUT P OSITIVE R EGULATORS P R O D U C T I O N A B S O L U T E M A X I M U M R AT I N G S D A T A S H E E T PACKAGE PIN OUTS (Note 1) Power Dissipation .................................................................................. Internally Limited Input Voltage ................................................................................................................ 10V Input to Output Voltage Differential ........................................................................... 10V Operating Junction Temperature Plastic (P Package) ................................................................................................ 150°C Storage Temperature Range ...................................................................... -65°C to 150°C Lead Temperature (Soldering, 10 seconds) ............................................................. 300°C Note 1. Exceeding these ratings could cause damage to the device. All voltages are with respect to Ground. Currents are positive into, negative out of the specified terminal. P PACKAGE: THERMAL RESISTANCE-JUNCTION TO TAB, θJT 2.7°C/W THERMAL RESISTANCE-JUNCTION TO AMBIENT, θ JA 60°C/W DD PACKAGE: THERMAL RESISTANCE-JUNCTION TO AMBIENT, θ JA 3 VIN VOUT ADJ / GND* 2 1 P PACKAGE (Top View) * Pin 1 is GND for fixed voltage versions. TAB IS V OUT T H E R MAL DATA THERMAL RESISTANCE-JUNCTION TO TAB, θJT TAB IS V OUT 2.7°C/W 60°C/W * 3 VIN 2 VOUT 1 ADJ / GND* DD PACKAGE (Top View) * Pin 1 is GND for fixed voltage versions. Junction Temperature Calculation: TJ = TA + (PD x θJA). The θ JA numbers are guidelines for the thermal performance of the device/pc-board system. All of the above assume no ambient airflow. * θ JAcan be improved with package soldered to 0.5IN2 copper area over backside ground plane or internal power plane. θJAcan vary from 20ºC/W to > 40ºC/W depending on mounting technique. 2 Copyright © 1997 Rev. 1.1 1/97 PRODUCT DATABOOK 1996/1997 LX8554-xx 5A E XTREMELY L OW D ROPOUT P OSITIVE R EGULATORS P R O D U C T I O N D A T A S H E E T ELECTRICAL CHARACTERISTICS (Unless otherwise specified, these specifications apply over the operating ambient temperatures for the LX8554-xxC with 0°C ≤ TA ≤ 125°C; VIN - V OUT = 3V; IOUT = 5A. Low duty cycle pulse testing techniques are used which maintains junction and case temperatures equal to the ambient temperature.) LX8554-00 (Adjustable) Parameter Reference Voltage Symbol Test Conditions VREF IOUT = 10mA, TA = 25°C 10mA ≤ IOUT ≤ 5A, 1.5V ≤ (VIN - VOUT), VIN ≤ 7V, P ≤ PMAX Line Regulation (Note 2) ∆VREF (VIN) IOUT = 10mA, 1.5V ≤ (VIN - VOUT ), VIN ≤ 7V ∆VREF (IOUT) VIN - V OUT = 3V, 10mA ≤ IOUT ≤ 5A Load Regulation (Note 2) ∆VOUT (Pwr) TA = 25°C, 20ms pulse Thermal Regulation Ripple Rejection (Note 3) VOUT = 3.3V, f =120Hz, COUT = 100µf Tantalum, VIN = 5V CADJ = 10µF, I OUT = 5A Adjust Pin Current I ADJ Adjust Pin Current Change ∆IADJ 10mA ≤ IOUT ≤ 5A, 1.5V ≤ (VIN - VOUT), VIN ≤ 7V Dropout Voltage ∆V ∆VREF = 1%, IOUT = 5A Minimum Load Current IOUT(MIN) VIN ≤ 7V Maximum Output Current (Note 4) I OUT(MAX) 1.4V ≤ (V IN - VOUT), VIN ≤ 7V Temperature Stability (Note 3) ∆VOUT (T) Long Term Stability (Note 3) ∆VOUT (t) TA = 125°C, 1000 hrs RMS Output Noise (% of VOUT) (Note 3) VOUT (RMS) TA = 125°C, 10Hz ≤ f ≤ 10kHz Min. 1.238 1.225 60 5.1 LX8554-00 Typ. Max. Units 1.250 1.250 0.035 0.1 0.01 83 1.262 1.275 0.2 0.5 0.02 V V % % %/W dB 55 0.2 0.8 2 7 0.25 100 5 1 10 µA µA V mA A % % % 1 0.003 LX8554-33 (3.3V Fixed) Parameter Output Voltage (Note 4) Symbol VOUT Test Conditions VIN = 5V, IOUT = 0mA, TA = 25°C 4.75V ≤ V IN ≤ 10V, 0mA ≤ IOUT ≤ 5A, TA = 25°C, P ≤ PMAX Line Regulation (Note 2) ∆VOUT 4.75V ≤ V IN ≤ 7V (VIN ) 4.75V ≤ VIN ≤ 10V Load Regulation (Note 2) ∆VOUT (IOUT) VIN = 5V, 10mA ≤ IOUT ≤ IOUT (MAX) Thermal Regulation (Note 3) ∆VOUT (Pwr) TA = 25°C, 20ms pulse Ripple Rejection (Note 3) COUT = 100µF (Tantalum), IOUT = 5A Quiescent Current IQ 0mA ≤ IOUT ≤ IOUT (MAX) , 4.75V ≤ VIN ≤ 10V Dropout Voltage ∆V ∆VOUT = 1%, IOUT ≤ IOUT (MAX) , VIN - VOUT ≤ 7V Maximum Output Current IOUT (MAX) VIN ≤ 7V Temperature Stability (Note 3) ∆VOUT (T) Long Term Stability (Note 3) ∆VOUT (t) TA = 125°C, 1000 hours RMS Output Noise (% of VOUT) (Note 3) VOUT (RMS) TA = 25°C, 10Hz ≤ f ≤ 10kHz Min. 3.267 3.235 65 5.1 LX8554-33 Typ. Max. 3.3 3.3 1 2 5 0.01 83 4 0.8 7 0.25 0.3 0.003 3.333 3.365 6 10 15 0.02 10 1 1 Units V V mV mV mV %/W dB mA V A % % % Note 2. Regulation is measured at constant junction temperature, using pulse testing with a low duty cycle. Changes in output voltage due to heating effects are covered under the specification for thermal regulation. Note 3. These parameters, although guaranteed, are not tested in production. Note 4. IOUT (MAX) is measured under the condition that VOUT is forced below its nominal value by 100mV. Copyright © 1997 Rev. 1.1 1/97 3 PRODUCT DATABOOK 1996/1997 LX8554-xx 5A E XTREMELY L OW D ROPOUT P OSITIVE R EGULATORS P R O D U C T I O N D A T A S H E E T A P P L I C AT I O N N O T E S The LX8554 is an easy to use Low-Dropout (LDO) voltage regulator. It has all of the standard self-protection features expected of a voltage regulator: short circuit protection, safe operating area protection and automatic thermal shutdown if the device temperature rises above approximately 165°C. Use of an output capacitor is REQUIRED with the LX8554A. Please see the table below for recommended minimum capacitor values. The regulator offers a more tightly controlled reference voltage tolerance and superior reference stability when measured against the older pin-compatible regulator types that it replaces. STABILITY The output capacitor is part of the regulator’s frequency compensation system. Many types of capacitors are available, with different capacitance value tolerances, capacitance temperature coefficients, and equivalent series impedances. For all operating conditions, connection of a 220µF aluminum electrolytic capacitor or a 47µF solid tantalum capacitor between the output terminal and ground will guarantee stable operation. If a bypass capacitor is connected between the output voltage adjust (ADJ) pin and ground, ripple rejection will be improved (please see the section entitled “RIPPLE REJECTION”). When ADJ pin bypassing is used, the required output capacitor value increases. Output capacitor values of 220µF (aluminum) or 47µF (tantalum) provide for all cases of bypassing the ADJ pin. If an ADJ pin bypass capacitor is not used, smaller output capacitor values are adequate. The table below shows recommended minimum capacitance values for stable operation. RECOMMENDED CAPACITOR VALUES INPUT OUTPUT ADJ 10µF 10µF 15µF Tantalum, 100µF Aluminum 47µF Tantalum, 220µF Aluminum None 15µF In order to ensure good transient response from the power supply system under rapidly changing current load conditions, designers generally use several output capacitors connected in parallel. Such an arrangement serves to minimize the effects of the parasitic resistance (ESR) and inductance (ESL) that are present in all capacitors. Cost-effective solutions that sufficiently limit ESR and ESL effects generally result in total capacitance values in the range of hundreds to thousands of microfarads, which is more than adequate to meet regulator output capacitor specifications. Output capacitance values may be increased without limit. The circuit shown in Figure 1 can be used to observe the transient response characteristics of the regulator in a power system under changing loads. The effects of different capacitor types and values on transient response parameters, such as overshoot and undershoot, can be quickly compared in order to develop an optimum solution. 4 Power Supply IN LX8554 OUT ADJ Minumum Load (Larger resistor) Full Load (Smaller resistor) RDSON