LP8358 150mA, µCap, Low Dropout Voltage Regulator with Power Good General Description Features The LP8358 is a µCap, precise CMOS voltage regulator with low Power good output RDSON. It provides up to 150mA and consumes a typical of 10nA in shutdown mode. The LP8358 output stage is designed with a push pull output for faster transient recovery response. The LP8358 is optimized to work with low value, low cost ceramic capacitors. The output typically require only 1µF of output capacitance for stability. The enable pin can be tied to VIN for easy board layout. The LP8358 is designed for portable, battery powered equipment applications with small space requirements. The LP8358 is available in a 5-pin SOT-23 package. Performance is specified for the −40˚C to +125˚C temperature range and is available in a fixed 1.2V. For other output voltage options, please contact National Semiconductor. n n n n n n n n n n Low power good RDSON: 20Ω Power good indicator Stability with low ESR capacitors Low ground current: 120µA 150mA output current "Zero" shutdown current mode Fast transient recovery response Auto discharge Thermal shutdown 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 5-Pin SOT-23 Part Number LP8358MF-1.2 LP8358MFX-1.2 © 2003 National Semiconductor Corporation DS200579 Package Marking LH2B Transport Media 1k Units Tape and Reel 3k Units Tape and Reel NSC Drawing MF05A www.national.com LP8358 150mA, µCap, Low Dropout Voltage Regulator with Power Good February 2003 LP8358 Connection Diagram SOT23-5 20057921 Top View Pin Description Pin Number www.national.com Pin Name Pin Function Input Voltage 1 VIN 2 GND 3 EN Enable Input Logic, Logic High = Enabled Logic Low = Shutdown (Do not leave open) 4 PG Power Good Output 5 VOUT Output Voltage Ground 2 LP8358 Block Diagram 20057920 3 www.national.com LP8358 Absolute Maximum Ratings Operating Ratings (Note 1) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltages VIN ESD Tolerance (Note 2) Human Body Model 2000V Junction Temperature 150˚C VIN, VOUT, VEN Storage Temperature Range −40˚C to +125˚C −65˚C to 150˚C Package Themal Resistance −0.3 TO 6.5V Infrared or Convection (20 sec) 0V to VIN Junction Temp. Range (Note 3) SOT23-5 Soldering Information Wave Soldering (10 sec) 2.7V to 6V VEN 235˚C/W 235˚C 260˚C (lead temp) Electrical Characteristics Unless otherwise specified, all limits guaranteed for TJ = 25˚C, VIN = 2.7V, IL = 100µA, COUT = 1µF, VEN ≥ 2.0V. Boldface limits apply over the entire operating temperature range, −40˚C to 125˚C. Symbol Parameter Conditions VO Output Voltage Accuracy IL = 100µA ∆VO/VO Line Regulation VIN = 2.7V to 6V ∆VO/VO Load Regulation IL = 0.1mA to 150mA (Note 6) IQ Quiescent Current VEN ≤ 0.4V (Shutdown), PG = NC IGND Ground Pin Current (Note 5) IL = 0mA, VEN ≥ 2.0V (active), VIN = 6V Min (Note 5) Typ (Note 4) -3 -4 −0.3 Max (Note 5) Units 3 4 % 0.3 % 4 % 0.01 1 µA 120 180 µA IL = 150mA, VEN ≥ 2.0V (active), VIN = 6V 160 225 62 dB 350 mA 150 ˚C PSRR Power Supply Rejection Ratio f = 120Hz, COUT = 4.7µF, IL = 150mA ILIMIT Current Limit VOUT = 0V 1 160 Thermal Protection Thermal Shutdown Temperature Enable Input VIL Enable Input Voltage Level VIH IIL Logic Low (off) , VIN = 5.5V Logic High (on), VIN = 5.5V Enable Input Current IIH 0.4 2 V V VIL ≤ 0.4V, VIN = 5.5V 0.01 µA VIH ≥ 2.0V, VIN = 5.5V 0.01 µA Power Good VPG Low Threshold % of VOUT (PG ON) 89 High Threshold % of VOUT (PG OFF) VOL PG Output Logic-Low Voltage IPOWERGOOD = 100µA, Fault Condition 2.0 RDSON Power Good Output On Resistance IPOWERGOOD = 1mA, Fault Condition 20 Ω IPG Power Good Leakage Current Power Good Off, VPG = 5.5V 0.01 µA VPG Delay Delay Time to Power Good See Timing Diagram 97 1 2.1 10.0 5 % mV 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 Characteristics. Note 2: Human body model, 1.5kΩ in series with 100pF. Note 3: The maximum power dissipation is a function of TJ(max) , θJA, and TA. 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. www.national.com 4 (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 5 www.national.com LP8358 Electrical Characteristics LP8358 Typical Performance Characteristics Unless otherwise specified, VIN = 3.3V, COUT = 1µF, TA = 25˚C and powergood pull up resistor = 47kΩ. Ground Current vs. Output Current Ground Current vs. Input Voltage 20057902 20057901 Ground Current vs. Temperature Short Circuit Current vs. Temperature 20057904 20057903 Short Circuit Current vs. Input Voltage Power Good Delay vs. Input Voltge 20057905 www.national.com 20057906 6 Power Good Delay vs. Temperature Power Good RDSON 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 7 www.national.com LP8358 Typical Performance Characteristics Unless otherwise specified, VIN = 3.3V, COUT = 1µF, TA = 25˚C and powergood pull up resistor = 47kΩ. (Continued) LP8358 Typical Performance Characteristics Unless otherwise specified, VIN = 3.3V, COUT = 1µF, TA = 25˚C and powergood pull up resistor = 47kΩ. (Continued) Enable Voltage vs. Temperature Voltage Noise vs. Frequency 20057912 20057923 PSRR vs. Frequency Power On Reset Delay Time 20057914 20057913 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 maintain stability. The capacitor must be at least 1µF or greater. The capacitor can be low-ESR ceramic chip capacitor, however for improved capacitance over temperature, tantalum capacitors can be used. 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 dramatically 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 response by significantly decreasing transient response recovery time during the transition from heavy load to light load. A 1µF input capacitor is recommend when the supply capacitance is more than 10 inches away from the device, or when the supply is a battery. X7R dielectric ceramic capacitors are recommended because of their temperature performance. X7R-type capacitor change capacitance by 15% over their operating temperature range and are the most stable type of ceramic capacitors. Z5U and Y5V dielectric capacitors change value by as much 50% and 60% respectively over their operating temperature range. To use a ceramic chip capacitor with Y5V dielectric, the value must be much higher than a X7/R ceramic 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. THERMAL BEHAVIOR The LP8358 regulator has internal thermal shutdown to protect the device from over heating. Under all operating conditions, 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 PD(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 temperature of the die, 125˚C. When operating the LP8358 at room temperature, the maximum power dissipation is 425mW. The actual power dissipated by the regulator is PD = (VIN –VOUT)IL +VIN IGND Substituting PD(MAX), determined above, for PD 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 shutdown, maximum power dissipation cannot be exceeded. 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 RDSON. It is designed essentially to work as a power-on reset generator once the regulated voltage is up and/ or a 9 www.national.com LP8358 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 diagram. The LP8358 internal circuit monitors overcurrent, temperature and falling output voltage. If one of these conditions is flagged this indicates a fault condition. Application Notes LP8358 150mA, µCap, Low Dropout Voltage Regulator with Power Good Physical Dimensions inches (millimeters) unless otherwise noted 5-Pin SOT23-5 NSC Package Number MF05A 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. 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