19-1422; Rev 0; 1/99 MAAS Low-Dropout, 300MA Linear Regulator in uMAX General Description The MAX8860 low-noise, low-dropout linear regulator operates from a +2.5V to +6.5V input and is guaran- teed to deliver 300mA. Typical output noise for this device is 60uVRms, and typical dropout is 105mvV at 200mA. In addition to the three available preset output voltages (+2.77V, +2.82V, and +3.3V), the Dual Mode feature allows the device to be configured as an adjustable output regulator from +1.25V to +6.5V. Designed with an internal P-channel MOSFET pass tran- sistor, the MAX8860 has a low 120UA supply current. An output fault-detection circuit indicates loss of regulation. Other features include a 10nA, logic-controlled shut- down mode, short-circuit and thermal-shutdown protec- tion, and reverse battery protection. The MAX8860 is available in a miniature 8-pin UMAX package. Applications Wireless Handsets DSP Core Power PCMCIA Cards Hand-Held Instruments Palmtop Computers Electronic Planners Typical Operating Circuit INPUT +2.5V TO IN OUT +6.5V MA AXLM MAX8860 SHDN OUT C1 2.2UF SET FAULT 7 t GND cc Features ft f+thUhC OO OHhU OHmhU Hh Hh OH High Output Current (300mA) Low Output Voltage Noise: 60pVRuMsS Low 105mV Dropout at 200mA Output Low 120yA No-Load Supply Current Thermal-Overload and Short-Circuit Protection Reverse Battery Protection 10nA Logic-Controlled Shutdown FAULT Indicator Small, Space-Saving HMAX Package (1.1mm max height) Small 2.2uF Output Capacitor Saves Space and Cost Ordering Information pin. OUTPUT PART TEMP. RANGE PACKAGE oy MAX8860EUA27 -40C to +85C }3=6 8 UMAX +2.77 MAX8860EUA28 -40C to +85C }3= 88 UMAX +2.82 MAX8860EUA33 -40C to +85C }3=68 UMAX +3.30 Pin Configuration TOP VIEW cout [| * 8] FAULT IN[o| ANAXUM FF apn | MAX8860 7 GND [3 | l6] cc out [4] [5 | SET uMAX Dual Mode is a trademark of Maxim Integrated Products. MAXIM Maxim Integrated Products 1 For free samples & the latest literature: http://)www.maxim-ic.com, or phone 1-800-998-8800. For small orders, phone 1-800-835-8769. O988XVWNMAX8860 Low-Dropout, 300MA Linear Regulator in uMAX ABSOLUTE MAXIMUM RATINGS IN, SHDN to GND ooo. ee eee eeeeeeeeeteeeeeetaeeeeeeaes -7V to +7V SHDN to IN ooo eee ee ee cee eee eee eeeteaeee tee eeee eee eeeeeeaee .-7V to +0.3V SET, CC, FAULT to GND uo. ence een eneee -0.3V to +7V OUT to GND oe ve we 0.3V to (VIN + 0.3V) FAULT Sink Current oo... cence neni eeesee seein Continuous Output Current .......... vo Output Short-Circuit Duration... eee eeee Continuous Power Dissipation (Ta = +70C) 8-Pin uUMAX (derate 4.1mW/C above +70C) we 330mW Thermal Resistance (6JA) 8-PIN UMAX octet eee eseeeneasceeeneaeeeeneneneee +244C/W Operating Temperature Range MAX8860EUA__ Junction Temperature... cece e eee eneaseeenenneeee Storage Temperature Range Lead Temperature (soldering, 10SC) ......ceeeeeee +300C Stresses beyond those listed under Absolute Maximum 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 = +3.6V, Coc = 33nF, Ta = -40C to +85C, unless otherwise noted. Typical values are at Ta = +25C.) (Note 1) PARAMETER CONDITIONS MIN TYP MAX | UNITS Input Voltage (Note 2) 2.5 6.5 Vv TA = +25C 3.24 3.3 3.35 MAX8860EUASS T, 40C 85C) 3.21 3.38 {00pA < lout A= 40C to + TA = +25C 2.78 2.82 2.87 Output Voltage <S00mA, MAX8860EUA28 A=* Vv VIN = VouT +1, Ta = -40C to +85C) 2.75 2.90 SET = GND TA = +25C 273. 277 2281 MAX8860EUA27 Ta = -40C to +85C| 2.70 2.84 = = TA = +25C 1.230 1248 1.267 SET Threshold Voltage SET = OUT, Vin = +2.5V to +6.5V, A=+ Vv louT = 1mA TA = -40C to +85C|] 1.220 1.275 Adjustable Output Voltage Range (Note 3) 1.25 6.5 V Maximum Output Current DC average current rating 300 mA Output Current Limit 330 770 mA louT = 0 120 270 Supply Current SET = GND HA louT = 300mA 165 Shutdown Supply Current Vour=0,SHDN= GND [JAS 28C Oo! A utdown Su urren = 0, = ppy Our Ta = +85C 0.05 i. louT = 1mA 0.6 Dropout Voltage (Note 4) louT = 200mA 105 220 mV louT = 300mA 155 Line Regulation VIN = +2.5V to +6.5V, SET = OUT, louT= 1mA -0.1 0.01 0.1 IN . SET = OUT 0.0001 Load Regulation louT = 100pA to 300mA %/mA SET = GND 0.0006 CouT = 2.2uF 65 . louT = 10mA, = Output Voltage Noise {OHz < f < 100kHz Cout = 10pF 60 HVRMS CouT = 100pF 55 Output Voltage Noise Density 10Hz < f < 100kHz CoutT = 10pF 190 nVVHz MAXUMLow-Dropout, 300MA Linear Regulator in uMAX ELECTRICAL CHARACTERISTICS (continued) (VIN = +3.6V, Coc = 33nF, Ta = -40C to +85C, unless otherwise noted. Typical values are at TA = +25C.) (Note 1) PARAMETER CONDITIONS MIN TYP MAX | UNITS VIH, 2.5V < VIN $ 5.5V 2.0 Vv SHDN Input Threshold VIL, 2.5V < VIN < 5.5V 0.4 Vv __ ; __ Ta = +25C 0.01 100 SHDN Input Bias Current SHDN = GND or IN nA TA = +85C 0.5 TA = +25C 0.01 2.5 SET Input Leakage Current (Note 3) | VseT = +1.3V nA TA = +85C 0.5 FAULT Detection Voltage (Note 5) SET = GND, lout = 200mA 130 280 mV FAULT Output Low Voltage VIN = +2.5V, ISINK = 2mA 0.25 Vv FAULT Output Off-Leakage Current | VFAULT = +3.6V TAs +256 oor 100 A utp ut Off-Leakage Curren FAULT = +3. Tan 485C 05 n Thermal Shutdown Temperature 170 C Thermal Shutdown Hysteresis 20 C Start-Up Time CouT = 10pF, VouT to 90% of final value 120 ys Note 1: Note 2: Note 3: Note 4: Note 5: Specifications to -40C are guaranteed by design and not production tested. Guaranteed by line-regulation test. Adjustable mode only. The dropout voltage is defined as (VIN - VoUT) when VouT is 100mV below the value of VouT for VIN = VoUT +2V. The FAULT detection voltage is the difference from input to output voltage. Maintain the input above this level to ensure good line and load regulation. Typical Operating Characteristics (VIN = VouT + 0.5V, CIN = CouT= 2.2uF, Coc = 33nF, Ta = +25C, unless otherwise noted.) 0.4 OUTPUT VOLTAGE (2%) Qo rw So hm -04 MAXLM NORMALIZED OUTPUT VOLTAGE NORMALIZED OUTPUT VOLTAGE vs. LOAD CURRENT vs. TEMPERATURE SUPPLY CURRENT vs. LOAD CURRENT a 0.3 T T T T THs 200 Vour NORMALIZED AT loor =0]/8 Vout NORMALIZED AT +25C, lour = 0] 180 Ta= 185C i 0.2 160 Ta = 425 = 04 = 10 Ta=-40C AS 2 | louy=0 120 3 lour=100mA | go POUT 2 100 | 5 ~._ o ~ ee le > 5 ot a 3} AJ! ad B 60 02 lour = 200mA [4 40 20 -0.3 0 50 100 150 200 250 300 -40 = -20 0 20 40 60 80 0 50 100 150 200 250 300 LOAD CURRENT (mA) TEMPERATURE (C) LOAD CURRENT (mA) O988XVWNMAX8860 Low-Dropout, 300MA Linear Regulator in uMAX Typical Operating Characteristics (continued) (VIN = VouT + 0.5V, CIN = CouT= 2.2uF, Coc = 33nF, Ta = +25C, unless otherwise noted.) NO LOAD SUPPLY CURRENT FAULT DETECT THRESHOLD vs. INPUT VOLTAGE DROPOUT VOLTAGE vs. LOAD CURRENT vs. LOAD CURRENT 200 : 180 g 250 s 3 160 g 3 e : : = 200 : _ 160 = = 140 Tas = WA S140 a 120 3 FAULT = HIGH Y 0 = 109 Ta = 485C B 150 A 5 ZB 100 a 5 = 30 5 FR 100 Qa qq ao 60 a B 60 ee 5 _ 40 z / FAULT = LOW 40 i 50 20 y 20 0 0 0 0 1 2 3 4 5 6 0 50 100 150 200 250 300 0 50 100 150 200 =250 300 INPUT VOLTAGE (V) LOAD CURRENT (mA) LOAD CURRENT (mA) POWER- SUPPLY REJECTION RATIO OUTPUT NOSE vs. FREQUENCY OUTPUT NOSE SPECTRAL DENSITY (10Hz TO 1MHz) 5 10 8 3 g ILoap = 1 3 1.0 a 8 z= > fF = Vout 2 500uV/ 2 04 div , ILoap = 200mA 0.01 0.01 0.1 1 10 100 1000 0.1 1 10 100 1000 ims/div FREQUENCY (kHz) FREQUENCY (kHz) LOAD- TRANSIENT RESPONSE LINE- TRANSIENT RESPONSE 200mA 7 e x | : 2 2 Oo 2 i 43V li 7 : oe : ~ coceeees | Vn fe | L + bel 43.3V F : Vour Lo ae 20mV/ ssbgateehanaa nef s7 einen wv Vy = Vour + 200mV Vout N ood. bo sete Vine Vout . fx. DOR 2mvi ed beds div poe : Do: : : Fe ILoaD = 200mA : 400us/div 500us/div 4 MAAXLMLow-Dropout, 300MA Linear Regulator in uMAX Typical Operating Characteristics (continued) (VIN = VouT + 0.5V, CIN = CouT= 2.2uF, Coc = 33nF, Ta = +25C, unless otherwise noted.) POWER- UP RESPONSE POWER- DOWN RESPONSE SHUTDOWN/POWER- UP AV AV av av i MAX8860 toc13 WT Nv 3V 3V av av WV SHON ov MAX8860 toct4 MAX8860 toc15. 3V av Vout iV 5ms/div 400us/div 2ms/div Pin Description PIN NAME FUNCTION 1,4 OUT Regulator Output. Bypass with 2.2uF, low-ESR capacitor to GND for stable operation. 2 IN Supply Input. Connect to power source (+2.5V to +6.5V). Bypass with 2.2uF capacitor to GND. 3 GND Ground 5 SET Output Voltage Set. Connect to GND for internally set threshold. Connect to resistor-divider for adjustable output voltages. See Output Voltage Selection section for more information. 6 cc Compensation Capacitor. Connect a 0.033pF capacitor from CC to GND. SHDN | Shutdown Input. Connect to IN for normal operation. Drive SHDN low to turn off the regulator. 8 FAULT Fault Output. A high-impedance, open-drain output. When the MAX8860 is out of regulation, FAULT goes low. In shutdown, the FAULT pin is high impedance. Connect to GND if unused. Detailed Description The MAX8860 is a_ low-dropout, low-quiescent-current linear regulator designed primarily for battery-powered applications. It supplies an adjustable +1.25V to +6.5V output voltage or a fixed-voltage +2.77V (MAX8860EUA27), +2.82V (MAX8860EUA28), or +3.30V (MAX8860EUA33) output for load currents up to 300mA. The devices with 2.77V and 2.82V nominal out- puts are designed to guarantee minimum output volt- ages of 2.70V and 2.75V, respectively. The device consists of a +1.25V reference, error amplifier, MOSFET driver, P-channel pass transistor, Dual Mode comparator, fault detector, and internal-feedback volt- age divider (Figure 1). The 1.25V bandgap reference is connected to the error amplifiers inverting input. The error amplifier compares this reference to the selected feedback voltage and MAXLM amplifies the difference. The MOSFET driver reads the error signal and applies the appropriate drive to the P- channel pass transistor. If the feedback voltage is lower than the reference voltage, the pass-transistor gate is pulled lower, allowing more current to pass and increasing the output voltage. If the feedback voltage is higher than the reference voltage, the pass-transistor gate is driven higher, allowing less current to pass to the output. The output voltage is fed back through either an internal resistor voltage divider connected to OUT, or an external resistor network connected to SET. The Dual Mode comparator examines VSET and selects the feedback path. If VseET is below 60mV, internal feedback is used and the output voltage is regulated to the preset output voltage. Additional blocks include an output current limiter, reverse battery protection, a ther- mal sensor, a fault detector, and shutdown logic. O988XVWNMAX8860 Low-Dropout, 300MA Linear Regulator in uMAX IN REVERSE _ BATTERY SHDN PROTECTION cc o+ MAXIM ac MAX8860 THERMAL SENSOR GND oe | MOS DRIVER P WITH Iuimir FAULT DETECT + DUAL-MODE = COMPARATOR I bom Figure 1. Functional Diagram Internal P-Channel! Pass Transistor The MAX8860 features a 0.5Q typical P-channel MOSFET pass transistor. This provides several advan- tages over similar designs using PNP pass transistors, including longer battery life. PNP-based regulators waste considerable amounts of current in dropout when the pass transistor saturates. They also use high base- drive currents under large loads. The P-channel MOSFET requires no base-drive current, which reduces quiescent current considerably. The MAX8860 con- sumes less than 165yA of quiescent current whether in dropout, light-load, or heavy-load applications (see Typical Operating Characteristics). Output Voltage Selection The MAX8860 features Dual Mode operation: it oper- ates in either a preset voltage mode or an adjustable mode. In preset voltage mode, internal, trimmed feed- back resistors set the output voltage to +2.77V (MAX8860EUA27), +2.82V (MAX8860EUA28), or +3.30V (MAX8860EUA33). Select this mode by con- necting SET to ground. In adjustable mode, select an output between 1.25V and 6.5V using two external resistors connected as a voltage divider to SET (Figure 2). Calculate the output voltage with the following equa- tion: Ri Vout = Vser (+2) OUTPUT VOLTAGE IN OUT MAXIMA MAX8860 Cin 2.2uF L SHDN SET BATTERY ry" 33nF. GND +4 Figure 2. Adjustable Output Using External Feedback Resistors where VSET = 1.25V. To simplify resistor selection, use the following equation: R1=R2 [You | VsET Choose R2 = 100kQ to optimize power consumption, accuracy, and high-frequency power-supply rejection. Ensure that the total current through the external resis- tive feedback and load resistors is not less than 10pA. Since the VseT tolerance is typically less than +20mV, set the output using fixed resistors instead of trim pots. MAKLow-Dropout, 300MA Linear Regulator in uMAX In preset voltage mode, connect SET to GND. Keep impedances between SET and ground to less than 100kQ. Otherwise, spurious conditions can cause VSET to exceed the 60mV Dual Mode threshold. Shutdown Drive SHDN low to place the MAX8860 in shutdown mode. In shutdown mode, the pass transistor, control circuit, reference, and all biases are turned off, reduc- ing the supply current to typically 10nA. Connect SHDN to IN for normal operation. Current Limit The MAX8860 includes short-circuit protection. It includes a current limiter that controls the pass transistors gate voltage, to limit the output current to about 770mA. For design purposes, the minimum current limit is 330mA. Thermal-Overload Protection Thermal-overload protection limits total power dissipa- tion in the MAX8860. When the junction temperature (Ty) exceeds +170C, the thermal sensor sends a sig- nal to the shutdown logic, turning off the pass transistor and allowing the IC to cool. The pass transistor turns on again after the ICs junction temperature typically cools by 20C, resulting in a pulsed output during continuous thermal-overload conditions. Thermal-overload protection is designed to protect the MAX8860 against fault conditions. Stressing the device with high-load currents and high input-output differen- tial voltages (which result in die temperatures above +125C) may cause a momentary over-shoot (2% to 8% for 200ms) when the load is completely removed. Remedy this by raising the minimum load current from O (+125C) to 100HA (+150C). This is accomplished with an external load resistor. For continuous operation, do not exceed the absolute maximum junction tempera- ture rating of +150C. Operating Region and Power Dissipation Maximum power dissipation of the MAX8860 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- sipated by the device is: P = lout (VIN - VouT). The maximum power dissipation is: PMAX = (TUMAX - TA) / 8JA where: TUMAX = +150C Ta is the ambient temperature QUA = 244C/W MAXUM The MAX8860's pins perform the dual function of provid- ing an electrical connection as well as channeling heat away from the die. Use wide circuit-board traces and large, solid copper polygons to improve power dissipa- tion. Using multiple vias to buried ground planes further enhances thermal conductivity. Reverse Battery Protection The MAX8860 has a unique protection scheme that lim- its the reverse supply current to less than 1mA when either VIN or VSHDN falls below ground. The circuitry monitors the polarity of these two pins, disconnecting the internal circuitry and parasitic diodes when the applied voltage is reversed. This feature prevents the device from overheating and damaging an improperly installed battery. Integrator Circuitry The MAX8860 uses an external 33nF compensation capacitor for minimizing load- and line-regulation errors and for lowering output noise. When the output voltage shifts due to varying load current or input voltage, the integrator capacitor voltage is raised or lowered to compensate for the systematic offset at the error ampli- fier. Compensation is limited to +5% to minimize tran- sient overshoot when the device goes out of dropout, current limit, or thermal shutdown. Fault-Detection Circuitry When the output voltage goes out of regulationsuch as during dropout, current limit, or thermal shutdown FAULT goes low. In addition, the fault-detection circuitry detects when the input-to-output voltage differential is insufficient to ensure good load and line regulation at the output. When the input-to-output voltage differential is less than 130mV for a load current of 200mA, FAULT also goes low. The differential threshold is designed to be always higher than and track with the dropout volt- age, and to scale proportionally with load current (see Fault Detect Threshold vs. Load Current graph in the Typical Operating Characteristics). The FAULT pin is an open-drain N-channel MOSFET. To create a voltage level output, connect a pull-up resistor from FAULT to OUT. To minimize current consumption, make this resistor as large as practical. A 100kQ resistor works well for most applications. O988XVWNMAX8860 Low-Dropout, 300MA Linear Regulator in uMAX Vin > +5.5V Minimum Load Current Requirements When operating the MAX8860 with an input voltage above +5.5V, a minimum load current of 20pA is required to maintain regulation in preset voltage mode. When setting the output with external resistors, ensure that the minimum current through the external feedback resistors and load is at least 30HA. This applies only when the input voltage exceeds +5.5V. For input volt ages less than +5.5V, the MAX8860 maintains regula- tion and stability without external loading. Applications Information Capacitor Selection and Regulator Stability Typically, use a 2.2uF capacitor on the input and a 2.2uF capacitor on the output of the MAX8860. Capacitor type is not critical, as long as it has an ESR less than 0.5Q. Larger capacitor values and lower ESR provide better supply-noise rejection and transient response. Use higher-value capacitors (10pF) if large, fast input or load transients are anticipated or if the device is located several inches from the power source. For stable operation over the full temperature range, with load currents up to 300mA, a minimum output- capacitor value of 2.2uF is recommended. There is no upper limit to capacitor size. The circuit used to gener- ate the typical operating characteristics data used 2.2uF X7R 16V (1206) ceramic capacitors. These capacitors have an ESR of typically 50mQ. Power-Supply Rejection and Operation from Sources Other than Batteries The MAX8860 is designed to deliver low dropout volt- age and low quiescent current in battery-powered sys- tems. Power-supply rejection is 67dB at low frequencies and rolls off above 100kHz. At high frequencies, the out- put capacitor is the major contributor to the rejection of power-supply noise (see the Power-Supply Rejection Ratio vs. Frequency graph in the Typical Operating Characteristics). When operating from sources other than batteries, improve supply-noise rejection and transient response by increasing the values of the input and output capaci- tors, and by using passive filtering techniques (see the supply and load-transient responses in the Typical Operating Characteristics). Load Transient Considerations The MAX8860 load-transient response graphs (see Typical Operating Characteristics) show the output response due to changing load current. Reduce over- shoot by increasing the output capacitors value and decreasing its ESR. Input-Output (Dropout) Voltage A regulator's minimum input-output voltage differential (or dropout voltage) determines the lowest usable supply voltage. In battery-powered systems, this determines the useful end-of-life battery voltage. Because the MAX8860 uses a P-channel MOSFET pass transistor, its dropout voltage is a function of Rps(on) (typically 0.52) multi- plied by the load current (see Electrical Characteristics). Chip Information TRANSISTOR COUNT: 148 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. 8 Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 1999 Maxim Integrated Products Printed USA MAXIMA is a registered trademark of Maxim Integrated Products.