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MAXIM MAX8869 1A MicroCap Low-Dropout Linear Regulator

1. OUTPUT NOISE vs OUTPUT CURRENT LINE TRANSIENT RESPONSE LOAD TRANSIENT RESPONSE 180 8 MAX8869 12 160 2 5V 1A VIN z e um 100mA 420 3 6V 100 oO 80 a 60 Vout 50mV div 5 10mV div Vout AC COUPLED 40 AC COUPLED on FLEE TL EE o peesi peipei oak lout 250mA 0 001 0 01 0 1 1 200us div 20us div OUTPUT CURRENT A LOAD TRANSIENT RESPONSE OUTPUT NOISE SHUTDOWN RESPONSE MAX8869 13 Maxaago 14 MAX8869 15 lout 1004A mr 3A Jor 10mA Ve BUI Abterrenbrrcsbeenbetechenie 100pV div 200mV div Vout AC COUPLED Vout 2V div 20us div 40us div SOFT START RESPONSE RESET OUTPUT RESPONSE MAX8869 16 MAX8869 17 VSHON 5V div 5V div 1A div lin 2V div OUTPUT DELAY Vout 2V div 2V div 10ms div 1ms div MAXIM 5 6988XVIN MAX8869 1A MicroCap Low Dropout Linear Regulator Pin Description FUNCTION No Connection Not internally connected Regulator Input Connect to power source 2 7V to 5 5V Bypass with 1uF or greater capacitor to GND see Capacitor Selection and Regulator Stability Connect all IN pins ogether for proper operation Reset Output Open drain output is low when Vout is 8 below its nominal value RST remains ow while the output voltage VouT is below the reset threshold and for at least 3ms after VOUT rises to within regulation Connect a 100kQ pullup resistor to OUT to obtain an output voltage Active Low Shu
2. MAXIM Linear Regulator SRF and ESR of 60mQ or less to ensure stability and optimum transient response This is particularly true in applications with very low output voltage lt 2V and high output current gt 0 5A Since some capacitor dielectrics may vary over bias voltage and temperature consult the capacitor manu facturer specifications to ensure that the capacitors meet these requirements over all voltage and tempera ture conditions used Soft Start Capacitor Selection A capacitor Css connected from SS to GND causes the MAX8869 output current to slowly rise during start up reducing stress on the input supply The rise time to full current limit tss is determined by tss 2 08 x 10 4 x Css where Css is in nF Typical capacitor values between 10nF to 100nF with a 5V rating are sufficient Because this ramp is applied to the current limit com parator the actual time for the output voltage to ramp up depends on the load current and output capacitor Leave SS open to disable soft start Input Output Dropout Voltage A regulator s minimum input to output voltage differen tial dropout voltage determines the lowest usable sup ply voltage In battery powered systems this determines the useful end of life battery voltage Since a 0 2Q P channel MOSFET is used as the pass device dropout voltage is the product of RDs ON and load current see Electrical Characteristics and Dropout Voltage vs Output Current in
3. Typical Operating Characteristics The MAX8869 operating current remains low in dropout Noise PSRR and Transient Response The MAX8869 is designed to achieve low dropout volt age and low quiescent current in battery powered sys tems while still maintaining good noise transient response and AC rejection see PSRR vs Frequency in the Typical Operating Characteristics When operat ing from very noisy sources supply noise rejection and transient response can be improved by increasing the values of the input and output capacitors and employ ing passive postfiltering MAX8869 output noise is typi cally 150uVRms see the Output Noise plot in the Typical Operating Characteristics Chip Information TRANSISTOR COUNT 1088 6988XVIN MAX8869 1A MicroCap Low Dropout Linear Regulator Package Information COMMON DIMENSIONS METER NCH TSSOP EPS 0135 0035 VARIATIONS SE 0 169 W EXPOSED DIE PAD TOP VIEW D K As kor eeh i A SEATING SEE E E D PLANE DETAIL r SIDE VIEW ND VIEW b 025 T bl Kg PARTING L TINE F WITH PLATING L L JE TA A Ke BASE METAL NOTES 1 DIMENSIONS D AND E DO NOT INCLUDE FLASH e MOLD FLASH OR PROTRUSIONS NOT TO EXCEED 1S mm PER SIDE 3 CONTROLLING DIMENSION MILLIMETER 4 MEETS JEDEC OUTLINE MO 153 VARIATIONS AB AC AD AE AF 5 DIMENSIONS X AND Y APPLY TO EXPOSED PAD CEP V
4. 19 1692 Rev 0 8 00 General Description The MAX8869 low dropout linear regulator operates from a 2 7V to 5 5V input and delivers a guaranteed 1A load current with a low 200mV dropout The high accuracy 1 output voltage is preset at 5V 3 3V 2 5V 1 8V or 1 0V or is adjustable from 0 8V to 5V with an external resistor divider The MAX8869 uses MicroCap technology and requires only a small 1uF output capacitor for guaran teed stability An internal PMOS pass transistor allows low 500A supply current making this regulator useful for networking and telecom hardware as well as bat tery operated equipment Other features include soft start low power shutdown short circuit protection and thermal shutdown protection The MAX8869 is available in a 1 5W 16 pin TSSOP package which is 30 smaller than a SOT223 and only 1 4mm high Applications Telecom Hardware Network Equipment Mobile Phone Base Stations Personal Computers Notebook Computers MicroCap is a trademark of Maxim Integrated Products Typical Operating Circuit MAXIM MAX8869 OUT UP TO 1A OUTPUT MAXIM MI AALS 1A MicroCap Low Dropout Guaranteed Low 200mV 1 Output gt gt o Linear Regulator Features 1A Output Current Stable with Court 1pF Dropout at 1A Voltage Accuracy Preset at 5V 3 3V 2 5V 1 8V or 1 0V and Adjustable from 0 8V to 5 0V 54dB PSRR gt gt gt a A High Pow
5. ERSIONS ONLY 6 EXPOSED PAD FLUSH WITH BOTTOM OF PACKAGE WITHIN Der SVIAAISVI PROPRIETARY INFORMATION TITLE PACKAGE OUTLINE TSSOP 4 40mm BODY 0 65mm PITCH APPROVAL DOCUMENT CONTROL NO REV 1 21 0066 C A Note The MAX8869EUE has an exposed thermal pad on the bottom side of the package Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product No circuit patent licenses are implied Maxim reserves the right to change the circuitry and specifications without notice at any time 10 Maxim Integrated Products 120 San Gabriel Drive Sunnyvale CA 94086 408 737 7600 2000 Maxim Integrated Products Printed USA MAXIM is a registered trademark of Maxim Integrated Products
6. IN for normal opera tion In shutdown RST is low and the soft start capaci tor is discharged RST Comparator The MAX8869 features a low VourT indicator that asserts when the output voltage falls out of regulation The open drain RST goes low when OUT falls 8 7 6988XVIN MAX8869 1A MicroCap Low Dropout Linear Regulator MAXUM MAX8869 Figure 3 Typical Operating Circuit with Adjustable Output Voltage below its nominal output voltage RST remains low for 3ms after OUT has returned to its nominal value A 100kQ pullup resistor from RST to a suitable logic sup ply voltage typically OUT provides a logic control sig nal RST can be used as a power on reset signal to a microcontroller uC or can drive an external LED for indicating a power failure RST is low during shutdown RST remains valid for an input voltage as low as 1V Soft Start As shown in Figure 4 a capacitor on SS allows a grad ual buildup of the MAX8869 output reducing the initial in rush current peaks at startup When SHDN is driven low the soft start capacitor is discharged When SHDN is driven high or power is applied to the device a con stant 6uA current charges the soft start capacitor The resulting linear ramp voltage on SS increases the cur rent limit comparator threshold limiting the P channel gate drive see Soft Start Capacitor Selection Leave SS floating to disable the soft start feature Current Limiting Th
7. MAX8869 ERROR AMP SHUTDOWN 736mV MOSFET DRIVER WITH FOLDBACK CURRENT LIMIT LOGIC Vss 92 VouT DELAY TI IN TC 3ms 0 8V REFERENCE Du DUAL MODE COMPARATOR Figure 1 Functional Diagram dl d Lal MAX8869 Cout lt tr RESET OUTPUT Figure 2 Typical Operating Circuit with Preset Output Voltage Output Voltage Selection The MAX8869 features Dual Mode operation Connect SET to GND Figure 2 for preset voltage mode see Ordering Information In adjustable mode set the out put between 0 8V to 5 0V through two external resis tors connected as a voltage divider to SET Figure 3 The output voltage is set by the following equation VOUT VSeET 1 R1 R2 MAXIM where VsET 0 8V To simplify resistor selection R1 R2 VouT VSET 1 Since the input bias current at SET is nominally 50nA large resistance values can be used for R1 and R2 to minimize power consumption without losing efficiency Up to 80kQ is acceptable for R2 In preset voltage mode the impedance between SET and ground should be less than 10kQ Otherwise spu rious conditions could cause the voltage at SET to exceed the 80mV Dual Mode threshold Shutdown A logic low on SHDN disables the MAX8869 In shut down the pass transistor control circuitry reference and all biases are turned off reducing supply current to typically 0 1uA Connect SHDN to
8. UT VOLTAGE vs INPUT VOLTAGE PSRR vs FREQUENCY 300 5 lout 500MA g IN DROPOUT Voy S 250 2 Ds E DROPOUT VOLTAGE mV S 25 3 0 3 5 4 0 45 5 0 INPUT VOLTAGE V FREQU ENCY kHz 000 VIN 5V VouT 2 5V SHDN IN SS open Court 1pF Ta 25 C unless otherwise noted MAX8869 03 MAX8869 06 MAX8869 09 GROUND CURRENT vs INPUT VOLTAGE 3 5 3 0 25 ce 2 0 Le 5 Ga 215 oO 5 10 KT 0 0 2 3 4 5 INPUT VOLTAGE V DROPOUT VOLTAGE vs OUTPUT CURRENT 450 400 350 E 300 2 250 S CG 200 O S 150 Le 100 50 0 0 250 500 750 1000 1250 1500 OUTPUT CURRENT mA OUTPUT NOISE SPECTRAL DENSITY vs FREQUENCY 10 lout 250mA a 1 SS E ES CH 04 0 01 Dm 0 4 1 0 00 1000 FREQUENCY kHz MAXIM 1A MicroCap Low Dropout Linear Regulator Typical Operating Characteristics continued VIN 5V VouT 2 5V SHDN IN SS open Court 1pF Ta 25 C unless otherwise noted
9. e pass transistor allowing the IC to cool The thermal sen sor turns the pass transistor on once the IC s junction temperature drops approximately 20 C Continuous short circuit conditions will consequently result in a pulsed output Thermal overload protection is designed to safeguard the MAX8869 in the event of fault conditions For con tinuous operation do not exceed the absolute maxi mum junction temperature rating of Ty 150 C Operating Region and Power Dissipation Maximum power dissipation of the MAX8869 depends on the thermal resistance of the case and circuit board the temperature difference between the die junction and ambient air and the rate of air flow The power dis sipation across the device is P lout VIN VouT The resulting maximum power dissipation is Pmax Tu MAX TA BUC 8CA where TJ MAX TA is the temperature difference between the maximum allowed die junction 150 C and the surrounding air yc junction to case is the MAXIM 1A MicroCap Low Dropout AXIMUM CONTINUOUS CURRENT VOLTAGE LIMIT TYPICAL DROPOU Es ES lu a Es 3 gt a gt gt ES TYPICAL SUPPLY VOLTAGE LIMIT INPUT OUTPUT DIFFERENTIAL VO Figure 5 Power Operating Region Maximum Output Current vs Input Output Differential Voltage thermal resistance of the package chosen and CA is the thermal resistance from the case through
10. e MAX8869 features a 4A current limit when the out put voltage is in regulation When the output voltage drops by 8 below its nominal the current limit folds back to 1 7A The output can be shorted to ground for an indefinite period of time without damaging the device Avoid continuous output current of more than 1A to prevent damage Both the in regulation and short circuit current limits can be reduced from their nominal values by reducing the voltage at the soft start pin SS below 1 25V The cur rent limits scale proportionately with the voltage by ILIM ILIM_NOM X Vss 1 25 Since the SS pin sources a nominal GuA current the current limit can be set by MAXIM MAX8869 Cout I IHF RESET OUTPUT Figure 4 Typical Operating Circuit with Soft Start and Current Limit Reduction tying a resistor Rss between SS and GND so that ILIM ILIM_NOM X Iss x Rss 1 25 where Iss 6A With Rss in place soft start can still be achieved by placing a capacitor Css in parallel with Rss The output current now ramps up asymptotically to the reduced current limit rather than the nominal one increasing the soft start time The time required for the current limit to reach 90 of its steady state value is given by tss 2 3 RssCss Thermal Overload Protection Thermal overload protection limits total power dissipa tion in the MAX8869 When the junction temperature exceeds Ty 170 C the thermal sensor turns off th
11. er at 100kHz Adjustable Soft Start 3ms Reset Output Foldback Output Current Limit Thermal Overload Protection 16 Pin TSSOP Package 1 5W 30 Smaller than SOT223 only 1 1mm high PART Ordering Information TEMP PIN Vout RANGE PACKAGE V MAX8869EUE50 40 C to 85 C 16 TSSOP EP 5 0 MAX8869EUE33 40 C to 85 C 16 TSSOP EP 3 3 MAX8869EUE25 MAX8869EUE18 MAX8869EUE10 40 C to 85 C 16 TSSOP EP 2 5 40 C to 85 C 16 TSSOP EP 1 8 40 C to 85 C 16 TSSOP EP 1 0 Or adjustable from 0 8V to 5 0V Contact factory for other preset output voltages ED Exposed pad TOP VIEW Pin Configuration MAXIM MAX8869 TSSOP EP Maxim Integrated Products 1 For free samples and the latest literature visit www maxim ic com or phone 1 800 998 8800 For small orders phone 1 800 835 8769 6988XVIN 1A MicroCap Low Dropout Linear Regulator ABSOLUTE MAXIMUM RATINGS IN SHDN RST SS to GND cic cstcsctelecreesenteadenenauee 0 3V to 6V Operating Temperature Range cee OUT SEV eeh ert ege eebe 0 3V to VIN 0 3V Junction Temperature s s sesean Output Short Circuit Duration Indefinite Storage Temperature Range Continuous Power Dissipation Ta 70 C Lead Temperature soldering 10s MAX8869 16 Pin TSSOP EP derate 19mW C above 70 C 1 5W Stresses beyond those listed under Absolute Ma
12. nput The error amplifier compares this refer ence with the selected feedback voltage and amplifies the difference The MOSFET driver reads the error sig nal and applies the appropriate drive to the P channel transistor If the feedback voltage is high the pass tran sistor s gate is pulled up allowing less current to pass to the output The low VouT comparator senses when the feedback voltage has dropped 8 below its expected level causing RST to go low The output voltage is fed back through either an inter nal resistor divider connected to OUT or an external resistor network connected to SET The Dual Mode comparator examines Vert and selects the feedback path If VSET is below 80mV the internal feedback path is used and the output voltage is regulated to the facto ry preset voltage Otherwise the output voltage is set with the external resistor divider Internal P Channel Pass Transistor The MAX8869 features a 1A P channel MOSFET pass transistor Unlike similar designs using PNP pass tran sistors P channel MOSFETs require no base drive which reduces quiescent current PNP based regula tors also waste considerable current in dropout when the pass transistor saturates and use high base drive currents under large loads The MAX8869 does not suf fer from these problems and consumes only 500A of quiescent current even in dropout MAXIM 1A MicroCap Low Dropout Linear Regulator SHUTDOWN SA AXIM Wee
13. nput Threshold 2 7V lt VIN lt 5 5V SHDN Input Bias Current SHDN GND or IN put Low Voltage ating Voltage Range for ISINK 104A VRST 5 5V Trip Level Referred to Nominal VouT Falling edge typical hysteresis 10mV ease Delay Rising edge Note 1 Dropout voltage is Vin VouT when Vour falls to 100mV below the value of Vout measured when VIN VOUT NOM 0 5V Since the minimum input voltage is 2 7V this specification is only meaningful when Vout 2 2 7V Note 2 The output voltage is externally set using a resistive voltage divider from OUT to SET Note 3 Specifications to 40 C are guaranteed by design not production tested MAXIM 3 6988XVIN MAX8869 1A MicroCap Low Dropout Linear Regulator OUTPUT VOLTAGE DEVIATION vs OUTPUT CURRENT Typical Operating Characteristics OUTPUT VOLTAGE DEVIATION vs TEMPERATURE MAX8869 02 MAX8869 05 MAX8869 08 0 S 15 05 3 10 S ES 1 0 05 a 5 Lu E 0 ZS S D 20 05 5 z 5 25 1 0 3 0 1 5 0 05 10 15 20 25 30 40 45 10 35 0 85 OUTPUT CURRENT A TEMPERATURE C GROUND CURRENT GROUND CURRENT vs OUTPUT CURRENT vs TEMPERATURE 3 5 i 30 S E 25 5 S 20 YE H 3 J 5 oO 5 Z ZS 10 g 0 5 0 0 200 400 600 800 1000 OUTPUT CURRENT mA TEMPERATURE C DROPO
14. old f 100kHz Cour 1uF SHDN GND Vin 5 5V VouT 0 2 7V lt VIN lt 5 5V SHDN Input Bias Curren SHDN GND or IN Soft Start Charge Curren RST Output Low Voltage IN Operating Voltage Range for RST Valid Vss 0 ISINK 1mA ISINK 10HA RST Leakage VRST 5 5V RST Trip Level Referred to Nominal VOUT RST Release Delay Falling edge typical hysteresis 10mV Rising edge Thermal Shutdown Threshold Typical thermal hysteresis 20 C 170 2 Dual Mode is a trademark of Maxim Integrated Products MAKINI 1A MicroCap Low Dropout Linear Regulator ELECTRICAL CHARACTERISTICS VIN 2 7V or VouT NOM 0 5V whichever is greater SHDN IN SS open SET GND Court 1pF Ta 40 C to 85 C unless otherwise noted Note 3 PARAMETER SYMBOL CONDITIONS Input Voltage Range Input Undervoltage Lockout ical hysteresis 50mV Output Voltage Accuracy T 1mMA Ta 85 C SET Regulation Voltage Adjustable Mode Load Regulation T 1mAto 1A Adjustable Output Voltage Range T 150mA Ta 85 C Maximum Output Current tinuous Short Circuit Current Limit T 0 In Regulation Current Limit VSET 0 76V SET Dual Mode Threshold SET Input Bias Current VSET 0 9V Ground Current loUT 100uA Dropout Voltage Note 1 lout 1A VouT 3 3V Note 2 Shutdown Supply Current SHDN GND Vin 5 5V VouT 0 SHDN I
15. tdown Input A logic low reduces the supply current to 0 1uA Connect SHDN o IN for normal operation In shutdown RST is low and the soft start capacitor discharges Selection Leave SS open to disable soft start Ground This pin and the exposed pad also function as a heatsink Solder both to a large pad or to the circuit board ground plane to maximize power dissipation Voltage Setting Input Connect SET to GND for factory preset output voltage Connect SET to an external resistor divider for adjustable output operation 7 SHDN 8 ss Soft Start Control Pin Connect a soft start capacitor from SS to GND see Soft Start Capacitor 10 GND 11 SET 12 13 14 15 OUT Regulator Output Bypass with a 1uF or greater low ESR capacitor to GND see Capacitor e Selection and Regulator Stability Connect all OUT pins together for proper operation Detailed Description The MAX8869 features Dual Mode operation allowing a fixed output of 5V 3 3V 2 5V 1 8V or 1 0V or adjustable output from 0 8V to 5 0V The regulators are guaranteed to supply 1A of continuous output cur rent with only 1uF of output capacitance As shown in the functional diagram Figure 1 the device has a 0 8V reference error amplifier MOSFET driver P channel pass transistor internal feedback voltage divider soft start function reset timer and Dual Mode and low VouT comparators The 0 8V reference is connected to the error amplifier s inverting i
16. the PC board copper traces and other materials to the sur rounding air Figure 5 shows the allowable power dissi pation for typical PC boards at 25 C 50 C and 70 C ambient temperatures The MAX8869 TSSOP EP package features an exposed thermal pad on its underside This pad lowers the package s thermal resistance by providing a direct thermal heat path from the die to the PC board Additionally the ground pin GND also channels heat Connect the exposed thermal pad and GND to circuit ground by using a large pad 1in2 minimum recom mended or multiple vias to the ground plane Applications Information Capacitor Selection and Regulator Stability Capacitors are required at the MAX8869 input and out put Connect 1uF or greater capacitors between IN and GND CIN and OUT and GND Cou Due to the MAX8869 s relatively high bandwidth use only surface mount ceramic capacitors that have low equivalent series resistance ESR and high self resonant frequen cy SRF Make the input and output traces at least 2 5mm wide the width of the four parallel pins and connect Cin and Cour within 6mm of the IC to mini mize the impact of PC board trace inductance The width of the ground trace should be maximized under neath the IC to ensure a good connection between pin 10 GND and the ground side of the capacitors The output capacitor s ESR and SRF can affect stability and output noise Use capacitors with greater than 5MHz
17. ximum Ratings may cause permanent damage to the device These are stress ratings only and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied Exposure to absolute maximum rating conditions for extended periods may affect device reliability ELECTRICAL CHARACTERISTICS VIN 2 7V or VoUT NOM 0 5V whichever is greater SHDN unless otherwise noted Typical values are at Ta 25 C PARAMETER SYMBOL Input Voltage Range CONDITIONS IN SS open SET GND Court 1pF Ta 0 C to 85 C Input Undervoltage Lockout Typical hysteresis 50mV Output Voltage Accuracy IOUT 1mA Ta 85 C SET Regulation Voltage Adjustable Mode louT 150mA Ta 85 C Line Regulation AVLNR ViN VouT 0 5V to 5 5V louT 10mA Load Regulation AVLDR louT 1mA to 1A Adjustable Output Voltage Range Maximum Output Current Short Circuit Current Limit tinuous VouT 0 In Regulation Current Limit VSET 0 76V SET Dual Mode Threshold SET Input Bias Current Ground Current VSET 0 9V louT 1004A lout 1A Dropout Voltage Note 1 lout IMA 2 7V lt ViN lt 5 5V lout 1A VouT 3 3V Note 2 Output Voltage Noise f 10Hz to 1MHz Cour 1uF lout 150mA Power Supply Rejection Ratio Shutdown Supply Current IOFF SHDN Input Thresh

MAXIM MAX8869 1A MicroCap Low-Dropout Linear Regulator

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