LP8358 NSC | Alldatasheet

Document overview

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Technical content

Features

n Low power good R DSON:2 0Ω n Power good indicator n Stability with low ESR capacitors n Low ground current: 120µA n 150mA output current n "Zero" shutdown current mode n Fast transient recovery response n Auto discharge n Thermal shutdown n Current limiting

Applications

n Processor power-up sequencing n Laptop, notebook and palm top computer n PCMCIA VCC and VPP regulation switching Typical Application 20057919

Ordering Information

Package Part Number Package Marking Transport Media NSC Drawing 5-Pin SOT-23 LP8358MF-1.2 LH2B 1k Units Tape and Reel MF05ALP8358MFX-1.2 3k Units Tape and Reel February 2003 LP8358 150mA, µCap, Low Dropout Voltage Regulator with Power Good © 2003 National Semiconductor Corporation DS200579 www.national.com

Pin Number Pin Name Pin Function 1V IN Input Voltage

2 GND Ground

3 EN Enable Input Logic,

Logic High = Enabled Logic Low = Shutdown (Do not leave open)

4 PG Power Good Output

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Absolute Maximum Ratings (Note 1) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. ESD Tolerance (Note 2) Human Body Model 2000V Junction Temperature 150˚C V IN,V OUT,V EN −0.3 TO 6.5V Soldering Information Infrared or Convection (20 sec) 235˚C Wave Soldering (10 sec) 260˚C (lead temp) Operating Ratings Supply Voltages VIN 2.7V to 6V VEN 0V to VIN Junction Temp. Range (Note 3) −40˚C to +125˚C Storage Temperature Range −65˚C to 150˚C Package Themal Resistance SOT23-5 235˚C/W

Electrical Characteristics

Unless otherwise specified, all limits guaranteed for T J = 25˚C, VIN = 2.7V, I L = 100µA, C OUT = 1µF, V EN ≥ 2.0V. Boldface limits apply over the entire operating temperature range, −40˚C to 125˚C. Symbol Parameter Conditions Min (Note 5) Typ (Note 4) Max (Note 5) Units VO Output Voltage Accuracy I L = 100µA -3 ∆VO/VO Line Regulation V IN = 2.7V to 6V −0.3 0.3 % ∆VO/VO Load Regulation I L = 0.1mA to 150mA (Note 6) 1 4 % IQ Quiescent Current V EN ≤ 0.4V (Shutdown), PG = NC 0.01 1 µA IGND Ground Pin Current (Note 5) I L = 0mA, V EN ≥ 2.0V (active), VIN =6 V 120 180 µA IL = 150mA, V EN ≥ 2.0V (active), VIN =6 V 160 225 PSRR Power Supply Rejection Ratio f = 120Hz, C OUT = 4.7µF, IL= 150mA 62 dB ILIMIT Current Limit V OUT =0 V 160 350 mA Thermal Protection Thermal Shutdown Temperature 150 ˚C Enable Input VIL Enable Input Voltage Level Logic Low (off) , V IN = 5.5V 0.4 V VIH Logic High (on), V IN = 5.5V 2 V IIL Enable Input Current V IL ≤ 0.4V, VIN = 5.5V 0.01 µA IIH VIH ≥ 2.0V, VIN = 5.5V 0.01 µA Power Good V PG Low Threshold % of V OUT (PG ON) 89 %High Threshold % of V OUT (PG OFF) 97 VOL PG Output Logic-Low Voltage IPOWERGOOD = 100µA, Fault Condition 2.0 10.0 mV RDSON Power Good Output On - Resistance IPOWERGOOD = 1mA, Fault Condition 20 Ω IPG Power Good Leakage Current Power Good Off, V PG = 5.5V 0.01 µA VPG Delay Delay Time to Power Good See Timing Diagram 1 2.1 5 ms Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is intended to be functional, but specific performance is not guaranteed. For guaranteed specifications and the test conditions, see the Electrical Ch aracteristics. Note 2: Human body model, 1.5k Ω in series with 100pF. Note 3: The maximum power dissipation is a function of T J(max) , θJA, and T A. The maximum allowable power dissipation at any ambient temperature is PD =( TJ(max)–T A)/θJA. All numbers apply for packages soldered directly into a PC board. Note 4: Typical Values represent the most likely parametric norm. Note 5: All limits are guaranteed by testing or statistical analysis. Note 6: Regulation is measured at constant junction temperature using low duty cycle pulse testing. LP8358 www.national.com 4

Electrical Characteristics (Continued) Note 7: Ground pin current is the regulator quiescent current. The total current drawn from the supply is the sum of the load current plus the ground pin current . Timing Diagram 20057915 Typical delay time to power good 20057925 LP8358 www.national.com5

Typical Performance Characteristics Unless otherwise specified, V IN = 3.3V, C OUT = 1µF, T A = 25˚C and powergood pull up resistor = 47k Ω. Ground Current vs. Output Current Ground Current vs. Input Voltage 20057901 20057902 Ground Current vs. Temperature Short Circuit Current vs. Temperature 20057903 20057904 Short Circuit Current vs. Input Voltage Power Good Delay vs. Input Voltge 20057905 20057906 LP8358 www.national.com 6

Typical Performance Characteristics Unless otherwise specified, V IN = 3.3V, C OUT = 1µF, T A = 25˚C and powergood pull up resistor = 47k Ω. (Continued) Power Good Delay vs. Temperature Power Good R DSON vs. Temperature 20057907 20057924 Output Voltage vs. Temperature Output Voltage vs. Input Voltage 20057908 20057909 Output Voltage vs. Output Current Enable Voltage vs. Input Voltage 20057911 20057922 LP8358 www.national.com7

Typical Performance Characteristics Unless otherwise specified, V IN = 3.3V, C OUT = 1µF, T A = 25˚C and powergood pull up resistor = 47k Ω. (Continued) Enable Voltage vs. Temperature Voltage Noise vs. Frequency 20057923 20057912 PSRR vs. Frequency Power On Reset Delay Time 20057913 20057914 LP8358 www.national.com 8

The LP8358 is a linear regulator with power good output designed to be used with a low ESR, low cost ceramic capacitors. EXTERNAL CAPACITORS The LP8358 regulator requires an output capacitor to main- tain stability. The capacitor must be at least 1µF or greater. The capacitor can be low-ESR ceramic chip capacitor, how- ever for improved capacitance over temperature, tantalum capacitors can be used. A 1µF input capacitor is recommend when the supply capaci- tance is more than 10 inches away from the device, or when the supply is a battery. X7R dielectric ceramic capacitors are recommended be- cause of their temperature performance. X7R-type capacitor change capacitance by 15% over their operating tempera- ture range and are the most stable type of ceramic capaci- tors. Z5U and Y5V dielectric capacitors change value by as much 50% and 60% respectively over their operating tem- perature range. To use a ceramic chip capacitor with Y5V dielectric, the value must be much higher than a X7/R ce- ramic or a tantalum capacitor to ensure the same minimum capacitance value over the operating temperature range. Tantalum capacitors have a very stable dielectric (10% over their operating temperature range) and can also be used with this device. ENABLE/SHUTDOWN The LP8358 has an active high enable pin that allows the regulator to be disabled. Applying a Logic Level low ( <0.4 V) to the Shutdown pin will cause the output to turn off, in this state current consumed by the regulator goes nearly to zero. Applying a Logic Level high ( >2.0V) enables the output voltage. The enable/shutdown pin must not be left floating; a floating enable pin may cause an indeterminate state on the output. ACTIVE SHUTDOWN The LP8358 is designed with a N-channel MOSFET that acts as a shutdown clamp. The N-channel turns on when the device is disabled to allow the output capacitor and load to discharge POWER GOOD The power good output is an open-drain output with extreme low R DSON. It is designed essentially to work as a power-on reset generator once the regulated voltage is up and/ or a fault condition. When a fault condition occurs, the output of the power good pin goes low. The power good output comes back up once the output has reached 97% of its nominal value and 1ms to 5ms delay has passed , see timing dia- gram. The LP8358 internal circuit monitors overcurrent, tempera- ture and falling output voltage. If one of these conditions is flagged this indicates a fault condition. The flagged condition output is fed into an onchip delay circuit that drives the open drain output transistor. TRANSIENT RESPONSE The LP8358 implements a unique output stage to dramati- cally improve transient response recovery time. The output is a totem-pole configuration with a P-channel MOSFET pass device and a N-channel MOSFET clamp. The N-channel clamp is a significantly smaller device that prevents the output voltage from overshooting when a heavy load is removed. This feature helps to speed up the transient re- sponse by significantly decreasing transient response recov- ery time during the transition from heavy load to light load. THERMAL BEHAVIOR The LP8358 regulator has internal thermal shutdown to pro- tect the device from over heating. Under all operating con- ditions, the maximum junction temperature of the LP8358 must be below 125˚C. Maximum power dissipation can be calculated based on the output current and the voltage drop across the part. The maximum power dissipation is P D(MAX) =( TJ(MAX) –TA )/θ JA θ JA is the junction-to-ambient thermal resistance, 235˚C/W for the LP8358 in the SOT23-5 package. TA is the maximum ambient temperature T J(MAX) is the maximum junction tem- perature of the die, 125˚C. When operating the LP8358 at room temperature, the maxi- mum power dissipation is 425mW. The actual power dissipated by the regulator is PD =( VIN –VOUT)IL +VIN IGND Substituting PD(MAX), determined above, for P D and solving for the operating condition that is critical to the application will give the maximum operating condition for the regulator circuit. To prevent the device from entering thermal shut- down, maximum power dissipation cannot be exceeded. LP8358 www.national.com9

Physical Dimensions inches (millimeters) unless otherwise noted 5-Pin SOT23-5 LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. National Semiconductor Americas Customer Support Center Email: new.feedback@nsc.com Tel: 1-800-272-9959 National Semiconductor Europe Customer Support Center Fax: +49 (0) 180-530 85 86 Email: europe.support@nsc.com Deutsch Tel: +49 (0) 69 9508 6208 English Tel: +44 (0) 870 24 0 2171 Français Tel: +33 (0) 1 41 91 8790 National Semiconductor Asia Pacific Customer Support Center Fax: +65-6250 4466 Email: ap.support@nsc.com Tel: +65-6254 4466 National Semiconductor Japan Customer Support Center Fax: 81-3-5639-7507 Email: jpn.feedback@nsc.com Tel: 81-3-5639-7560 www.national.com LP8358 150mA, µCap, Low Dropout Voltage Regulator with Power Good National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the righ t at any time without notice to change said circuitry and specifications.