MAX8869 1A, Microcap, Low-Dropout, Linear Regulator 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 highaccuracy (±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 1µF output capacitor for guaranteed stability. An internal PMOS pass transistor allows low 500µA supply current, making this regulator useful for networking and telecom hardware as well as battery-operated equipment. Other features include softstart, 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 1.1mm high. Features o o o o Guaranteed 1A Output Current Stable with COUT = 1µF Low 200mV Dropout at 1A ±1% Output Voltage Accuracy Preset at +5V, +3.3V, +2.5V, +1.8V, or +1.0V and Adjustable from +0.8V to +5.0V o 54dB PSRR at 100kHz o o o o o Adjustable Soft-Start 3ms Reset Output Foldback Output Current Limit Thermal Overload Protection High-Power 16-Pin TSSOP Package (1.5W) 30% Smaller than SOT223 (Only 1.1mm High) Ordering Information PART ________________________Applications PIN-PACKAGE VOUT (V)* MAX8869EUE50+ 16 TSSOP-EP** +5.0 +3.3 MAX8869EUE33+ 16 TSSOP-EP** Telecom Hardware MAX8869EUE25+ 16 TSSOP-EP** +2.5 Network Equipment MAX8869EUE25/V+ 16 TSSOP-EP** +2.5 Mobile Phone Base Stations MAX8869EUE18+ 16 TSSOP-EP** +1.8 Personal Computers MAX8869EUE10+ 16 TSSOP-EP** Notebook Computers Microcap is a registered trademark of American Technical Ceramics Corp. +1.0 Note: All devices are specified over the -40°C to +85°C temperature range. +Denotes a lead(Pb)-free/RoHS-compliant package. *Or adjustable from +0.8V to +5.0V. Contact factory for other preset output voltages. **EP = Exposed pad. /V denotes an automotive qualified part. Pin Configuration Typical Operating Circuit TOP VIEW + MAX8869 VIN +2.7V TO +5.5V 1µF ON OFF IN OUT IN OUT IN OUT IN OUT SHDN RST SS SET GND VOUT UP TO 1A 1µF RESET OUTPUT N.C. 1 16 N.C. IN 2 15 OUT 14 OUT IN 3 IN 4 MAX8869 13 OUT IN 5 12 OUT RST 6 11 SET SHDN 7 10 GND 9 SS 8 N.C. TSSOP-EP For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com. 19-1692; Rev 2; 10/12 MAX8869 1A, Microcap, Low-Dropout, Linear Regulator ABSOLUTE MAXIMUM RATINGS IN, SHDN, RST, SS to GND ......................................-0.3V to +6V OUT, SET to GND ........................................-0.3V to (VIN + 0.3V) Output Short-Circuit Duration ........................................Indefinite Continuous Power Dissipation (TA = +70°C) 16-Pin TSSOP-EP (derate 26.1mW/°C above +70°C)......2.0W Operating Temperature Range ...........................-40°C to +85°C Junction Temperature ......................................................+150°C Storage Temperature Range ...............................-65°C to 150°C Lead Temperature (soldering, 10s) .................................+300°C Soldering Temperature (reflow) .......................................+260°C 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 = +2.7V or VOUT(NOM) + 0.5V (whichever is greater), SHDN = IN, SS = open, SET = GND, COUT = 1µF, TA = 0°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER Input Voltage Range SYMBOL CONDITIONS VIN MIN TYP 2.7 Input Undervoltage Lockout Typical hysteresis = 50mV Output Voltage Accuracy IOUT = 1mA, TA = +85°C SET Regulation Voltage (Adjustable Mode) IOUT = 150mA, TA = +85°C Line Regulation ∆VLNR VIN = VOUT + 0.5V to +5.5V, IOUT = 10mA Load Regulation Adjustable Output Voltage Range ∆VLDR IOUT = 1mA to 1A 2.35 2.45 -1 792 800 MAX UNITS 5.5 V 2.55 V 1 % 808 mV 0.1 0.8 0.8 %/V 1.5 5 %/A V Maximum Output Current IOUT Continuous 1 Short-Circuit Current Limit ILIM VOUT = 0V 1.0 1.9 A In-Regulation Current Limit ILIM VSET = 0.76V 2.0 4.0 A 40 80 120 mV VSET = +0.9V 50 300 nA IOUT = 100µA 0.5 2.0 IOUT = 1A 2.5 SET Dual Mode Threshold SET Input Bias Current Ground Current ISET IGND ARMS Dropout Voltage (Note 1) IOUT = 1mA, +2.7V < VIN < +5.5V 0.2 IOUT = 1A, VOUT = +3.3V (Note 2) 200 Output Voltage Noise f = 10Hz to 1MHz, COUT = 1µF, IOUT = 150mA 150 Power-Supply Rejection Ratio Shutdown Supply Current SHDN Input Threshold PSRR IOFF VIH VIL SHDN Input Bias Current Soft-Start Charge Current ISS f = 100kHz, COUT = 1µF 54 SHDN = GND, VIN = +5.5V, VOUT = 0 0.1 +2.7V < VIN < +5.5V SHDN = GND or IN 0 6 ISINK = 1mA IN Operating Voltage Range for RST Valid ISINK = 10µA RST Leakage V RST = +5.5V RST Trip Level Referred to Nominal VOUT Falling edge, typical hysteresis = 10mV 89 Rising edge 1 Thermal Shutdown Threshold 2 TSHDN Typical thermal hysteresis = +20°C Dual Mode is a trademark of Maxim Integrated Products. dB 10 0.6 VSS = 0V mV µVRMS 1.6 RST Output Low Voltage RST Release Delay 350 mA 0.1 µA V µA µA 0.1 V 5.5 V 0.01 1 µA 92 95 % OUT 3 5.5 ms 1.0 +170 o C Maxim Integrated MAX8869 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, COUT = 1µF, TA = -40°C to +85°C, unless otherwise noted.) (Note 3) PARAMETER Input Voltage Range SYMBOL CONDITIONS VIN MIN MAX UNITS 2.7 5.5 V Input Undervoltage Lockout Typical hysteresis = 50mV 2.3 2.6 V Output Voltage Accuracy IOUT = 1mA, TA = +85°C -1 1 % SET Regulation Voltage (Adjustable Mode) IOUT = 150mA, TA = +85°C 792 808 mV 2.0 %/A Load Regulation ∆VLDR IOUT = 1mA to 1A Adjustable Output Voltage Range 0.8 5 V Maximum Output Current IOUT Continuous 1 ARMS Short-Circuit Current Limit ILIM VOUT = 0V 1.0 A In-Regulation Current Limit ILIM VSET = +0.76V 2.0 SET Dual Mode Threshold 40 SET Input Bias Current ISET Ground Current IGND Dropout Voltage (Note 1) Shutdown Supply Current SHDN Input Threshold IOFF VIH VIL VSET = +0.9V A 120 mV 300 nA IOUT = 100µA 2.0 mA IOUT = 1A, VOUT = +3.3V (Note 2) 350 mV 10 µA SHDN = GND, VIN = +5.5V, VOUT = 0V +2.7V < VIN < +5.5V 1.7 0.6 V SHDN Input Bias Current SHDN = GND or IN 0.1 µA RST Output Low Voltage ISINK = 1mA 0.1 V IN Operating Voltage Range for RST Valid ISINK = 10µA 5.5 V RST Leakage V RST = +5.5V 1 µA RST Trip Level Referred to Nominal VOUT Falling edge, typical hysteresis = 10mV 88 95 % OUT RST Release Delay Rising edge 1 6 ms 1.0 Note 1: Dropout voltage is (VIN - VOUT) when VOUT 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 ≥ 2.7V. 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 Integrated 3 MAX8869 1A, Microcap, Low-Dropout, Linear Regulator Typical Operating Characteristics (VIN = +5V, VOUT = +2.5V, SHDN = IN, SS = open, COUT = 1µF, TA = +25°C, unless otherwise noted.) OUTPUT VOLTAGE DEVIATION vs. TEMPERATURE -1.0 -1.5 -2.0 VIN = +3V -2.5 IOUT = 250mA 0.5 0 -0.5 -1.0 0.5 1.0 1.5 2.0 2.5 -15 10 35 60 85 0 1 2 3 4 5 GROUND CURRENT vs. TEMPERATURE DROPOUT VOLTAGE vs. OUTPUT CURRENT GROUND CURRENT (mA) VIN = +3V 1.5 1.0 2.0 IOUT = 250mA 1.5 VIN = +5V VIN = +3V 1.0 0.5 450 VOUT = +3.3V 400 DROPOUT VOLTAGE (mV) MAX8869-04 VIN = +5V 2.5 2.0 2.5 MAX8869-06 GROUND CURRENT vs. OUTPUT CURRENT 350 300 250 200 150 100 IOUT = 0V 50 0 0 0 400 600 800 1000 -40 -15 10 35 60 0 85 250 500 750 1000 1250 1500 TEMPERATURE (°C) OUTPUT CURRENT (mA) DROPOUT VOLTAGE vs. INPUT VOLTAGE PSRR vs. FREQUENCY OUTPUT NOISE SPECTRAL DENSITY vs. FREQUENCY IOUT = 500mA IN DROPOUT, VOUT ≅ VIN 60 10 MAX8869-09 OUTPUT CURRENT (mA) MAX8869-08 200 MAX8869-07 0 IOUT = 250mA 150 40 30 100 20 50 10 0 0 2.5 3.0 3.5 4.0 INPUT VOLTAGE (V) 4.5 5.0 NOISE (µV/√Hz) 50 200 PSRR (dB) DROPOUT VOLTAGE (mV) IOUT = 0A INPUT VOLTAGE (V) 0.5 4 1.0 TEMPERATURE (∞C) 3.0 250 1.5 OUTPUT CURRENT (A) 3.5 300 2.0 0 -40 3.0 IOUT = 0.5A 2.5 0.5 MAX8869-05 0 IOUT = 1A 3.0 -1.5 -3.0 GROUND CURRENT (mA) 1.0 GROUND CURRENT (mA) VIN = +5V 3.5 MAX8869-02 -0.5 1.5 OUTPUT VOLTAGE DEVIATION (%) MAX8869-01 OUTPUT VOLTAGE DEVIATION (%) 0 GROUND CURRENT vs. INPUT VOLTAGE MAX8869-03 OUTPUT VOLTAGE DEVIATION vs. OUTPUT CURRENT IOUT = 300mA 0.01 0.1 1 0.1 0.01 1 10 FREQUENCY (kHz) 100 1000 0.01 0.1 1 10 100 1000 FREQUENCY (kHz) Maxim Integrated MAX8869 1A, Microcap, Low-Dropout, Linear Regulator Typical Operating Characteristics (continued) (VIN = +5V, VOUT = +2.5V, SHDN = IN, SS = open, COUT = 1µF, TA = +25°C, unless otherwise noted.) OUTPUT NOISE vs. OUTPUT CURRENT LINE-TRANSIENT RESPONSE MAX8869-10 160 OUTPUT NOISE (µVRMS) LOAD-TRANSIENT RESPONSE MAX8869-11 180 MAX8869-12 5V VIN 140 1A IOUT 100mA 3.6V 120 100 80 VOUT 60 50mV/div AC-COUPLED VOUT 10mV/div AC-COUPLED 40 20 IOUT = 250mA 0 0.001 0.01 0.1 1 200µs/div 20µs/div OUTPUT CURRENT (A) LOAD-TRANSIENT RESPONSE OUTPUT NOISE SHUTDOWN RESPONSE MAX8869-13 MAX8869-14 MAX8869-15 1MHz BANDWIDTH IOUT = 100µA 3A IOUT 10mA VSHDN 5V/div VOUT 2V/div 100µV/div 200mV/div AC-COUPLED VOUT 20µs/div 4ms/div 40µs/div RESET OUTPUT RESPONSE SOFT-START RESPONSE MAX8869-17 MAX8869-16 VSHDN 5V/div VIN 5V/div 1A/div IIN VOUT VOUT 2V/div 2V/div RST OUTPUT DELAY 2V/div RST CSS = 100nF 10ms/div Maxim Integrated 1ms/div 5 MAX8869 1A, Microcap, Low-Dropout, Linear Regulator Pin Description PIN NAME FUNCTION 1, 9, 16 N.C. 2, 3, 4, 5 IN 6 RST Reset Output. Open-drain output is low when VOUT is 8% below its nominal value. RST remains low while the output voltage (VOUT) is below the reset threshold and for at least 3ms after VOUT rises to within regulation. Connect a 100kΩ pullup resistor to OUT to obtain an output voltage. 7 SHDN Active-Low Shutdown Input. A logic low reduces the supply current to 0.1µA. Connect SHDN to IN for normal operation. In shutdown, RST is low and the soft-start capacitor discharges. 8 SS 10 GND Ground. Solder both GND and EP to a large pad or to the circuit-board ground plane to maximize power dissipation. 11 SET Voltage-Setting Input. Connect SET to GND for factory-preset output voltage. Connect SET to an external resistor-divider for adjustable output operation. 12, 13, 14, 15 OUT Regulator Output. Bypass with a 1µF or greater low-ESR capacitor to GND (see Capacitor Selection and Regulator Stability). Connect all OUT outputs together for proper operation. — EP No Connection. Not internally connected. Regulator Input. Connect to power source (+2.7V to +5.5V). Bypass with 1µF or greater capacitor to GND (see Capacitor Selection and Regulator Stability). Connect all IN inputs together for proper operation. Soft-Start Control. Connect a soft-start capacitor from SS to GND (see Soft-Start Capacitor Selection). Leave SS open to disable soft-start. Exposed Pad. Connect to a large ground plane to maximize thermal performance. Not intended as an electrical connection point. 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 current with only 1µF 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 input. The error amplifier compares this reference with the selected feedback voltage and amplifies the difference. The MOSFET driver reads the error signal and applies the appropriate drive to the P-channel transistor. If the feedback voltage is high, the pass transistor’s gate is pulled up, allowing less current to pass to the output. The low VOUT comparator senses when 6 the feedback voltage has dropped 8% below its expected level, causing RST to go low. The output voltage is fed back through either an internal resistor-divider connected to OUT or an external resistor network connected to SET. The Dual Mode comparator examines VSET and selects the feedback path. If VSET is below 80mV, the internal feedback path is used and the output voltage is regulated to the factory-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 transistors, P-channel MOSFETs require no base drive, which reduces quiescent current. PNP-based regulators also waste considerable current in dropout when the pass transistor saturates and use high base-drive currents under large loads. The MAX8869 does not suffer from these problems and consumes only 500µA of quiescent current even in dropout. Maxim Integrated MAX8869 1A, Microcap, Low-Dropout, Linear Regulator IN SHUTDOWN THERMAL SENSOR MAX8869 ERROR AMP SHUTDOWN LOGIC SHDN MOSFET DRIVER WITH FOLDBACK CURRENT LIMIT PMOS VSS OUT 92% VOUT DETECTOR DELAY TIMER IN RST 736mV 3ms NMOS OUT 0.8V REFERENCE SET R1 6µA DUAL MODE COMPARATOR VSS SS 80mV R2 GND Figure 1. Functional Diagram where VSET = +0.8V. To simplify resistor selection: MAX8869 VIN CIN 1µF ON OFF CSS IN OUT IN OUT IN OUT IN OUT SHDN RST SS SET GND COUT 1µF VOUT RESET OUTPUT 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 80kΩ is acceptable for R2. In preset voltage mode, the impedance between SET and ground should be less than 10kΩ. Otherwise, spurious conditions could cause the voltage at SET to exceed the 80mV Dual Mode threshold. Shutdown 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 output between +0.8V to +5.0V through two external resistors connected as a voltage-divider to SET (Figure 3). The output voltage is set by the following equation: VOUT = VSET (1 + R1 / R2) Maxim Integrated A logic low on SHDN disables the MAX8869. In shutdown, the pass transistor, control circuitry, reference, and all biases are turned off, reducing supply current to typically 0.1µA. Connect SHDN to IN for normal operation. In shutdown, RST is low and the soft-start capacitor is discharged. RST Comparator The MAX8869 features a low V OUT indicator that asserts when the output voltage falls out of regulation. The open-drain RST goes low when OUT falls 8% 7 MAX8869 1A, Microcap, Low-Dropout, Linear Regulator MAX8869 VIN CIN 1µF ON OFF MAX8869 IN OUT IN OUT IN OUT IN OUT IN OUT IN OUT IN OUT IN OUT SHDN RST SHDN RST SS SET GND SS R1 COUT 1µF VOUT RESET OUTPUT VIN CIN 1µF ON OFF SET GND CSS RSS COUT 1µF VOUT RESET OUTPUT R2 Figure 3. Typical Operating Circuit with Adjustable Output Voltage Figure 4. Typical Operating Circuit with Soft-Start and CurrentLimit Reduction below its nominal output voltage. RST remains low for 3ms after OUT has returned to its nominal value. A 100kΩ pullup resistor from RST to a suitable logic supply voltage (typically OUT) provides a logic control signal. RST can be used as a power-on-reset signal to a microcontroller (µC) 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. tying a resistor (RSS) between SS and GND, so that ILIM = ILIM_NOM (ISS RSS / 1.25) where ISS = 6µA . 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 softstart time. The time required for the current limit to reach 90% of its steady-state value is given by t SS = 2.3 RSSCSS. Soft-Start As shown in Figure 4, a capacitor on SS allows a gradual 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 constant 6µA current charges the soft-start capacitor. The resulting linear ramp voltage on SS increases the current-limit comparator threshold, limiting the P-channel gate drive (see Soft-Start Capacitor Selection). Leave SS unconnected to disable the soft-start feature. Current Limiting The MAX8869 features a 4A current limit when the output 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 input (SS) below 1.25V. The current limits scale proportionately with the voltage by ILIM = ILIM_NOM (VSS / 1.25). Since the SS input sources a nominal 6µA current, the current limit can be set by 8 Thermal Overload Protection Thermal overload protection limits total power dissipation in the MAX8869. When the junction temperature exceeds TJ = +170°C, the thermal sensor turns off the pass transistor, allowing the IC to cool. The thermal sensor 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 continuous operation, do not exceed the absolute maximum junction temperature rating of TJ = +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 dissipation across the device is P = IOUT (VIN - VOUT). The resulting maximum power dissipation is: PMAX = [(TJ(MAX) - TA) / (θJC + θCA)] where (T J(MAX) - T A ) is the temperature difference between the maximum allowed die junction (150°C) and the surrounding air; θJC (junction to case) is the Maxim Integrated MAX8869 1A, Microcap, Low-Dropout, Linear Regulator SRF and ESR of 60mΩ or less to ensure stability and optimum transient response. This is particularly true in applications with very low output voltage (<2V) and high output current (>0.5A). 1.2 1.0 0.6 0.4 TYPICAL SUPPLY VOLTAGE LIMIT TA = +25°C 0.8 TYPICAL DROPOUT VOLTAGE LIMIT MAXIMUM OUTPUT CURRENT (A) MAXIMUM CONTINUOUS CURRENT TA = +50°C TA = +70°C 0.2 TJ = +150°C Since some capacitor dielectrics may vary over bias voltage and temperature, consult the capacitor manufacturer specifications to ensure that the capacitors meet these requirements over all voltage and temperature conditions used. Soft-Start Capacitor Selection 0 0 1 2 3 4 5 INPUT-OUTPUT DIFFERENTIAL VOLTAGE Figure 5. Power Operating Region: Maximum Output Current vs. Input-Output Differential Voltage thermal resistance of the package chosen, and θCA is the thermal resistance from the case through the PC board, copper traces, and other materials to the surrounding air. Figure 5 shows the allowable power dissipation 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, GND also channels heat. Connect the exposed thermal pad and GND to circuit ground by using a large pad (1in2 minimum recommended) or multiple vias to the ground plane. Applications Information Capacitor Selection and Regulator Stability Capacitors are required at the MAX8869 input and output. Connect 1µF or greater capacitors between IN and GND (C IN ) and OUT and GND (C OUT ). Due to the MAX8869’s relatively high bandwidth, use only surfacemount ceramic capacitors that have low equivalent series resistance (ESR) and high self-resonant frequency (SRF). Make the input and output traces at least 2.5mm wide (the width of the four parallel inputs and outputs), and connect CIN and COUT within 6mm of the IC to minimize the impact of PC board trace inductance. The width of the ground trace should be maximized underneath the IC to ensure a good connection between 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 Maxim Integrated A capacitor (CSS) connected from SS to GND causes the MAX8869 output current to slowly rise during startup, reducing stress on the input supply. The rise time to full current limit (tSS) is determined by: tSS = 2.08 10-4 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 comparator, 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 differential (dropout voltage) determines the lowest usable supply voltage. In battery-powered systems, this determines the useful end-of-life battery voltage. Since a 0.2Ω 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 Typical Operating Characteristics ). The MAX8869 operating current remains low in dropout. Noise, PSRR, and Transient Response The MAX8869 is designed to achieve low dropout voltage and low quiescent current in battery-powered systems while still maintaining good noise, transient response, and AC rejection (see PSRR vs. Frequency in the Typical Operating Characteristics). When operating from very noisy sources, supply noise rejection and transient response can be improved by increasing the values of the input and output capacitors and employing passive postfiltering. MAX8869 output noise is typically 150µV RMS. (see the Output Noise plot in the Typical Operating Characteristics). 9 MAX8869 1A, Microcap, Low-Dropout, Linear Regulator Package Information Chip Information PROCESS: BiCMOS 10 For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO. 16 TSSOP U16E+3 21-0108 90-0120 Maxim Integrated MAX8869 1A, Microcap, Low-Dropout, Linear Regulator Revision History REVISION NUMBER REVISION DATE 0 8/00 Initial release 1 6/10 Added lead-free versions to Ordering Information, updated Continuous Power Dissipation and added Soldering Temperature to Absolute Maximum Ratings, and added EP row to Pin Description 2 10/12 Added automotive qualified part to Ordering Information DESCRIPTION PAGES CHANGED — 1, 2, 6 1 Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000 ________________________________ 11 © 2012 Maxim Integrated Products, Inc. Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project