19-0485; Rev 0; 4/96 Dual, Low-Dropout, 100mA Linear Regulators ____________________________Features The MAX8865 and MAX8866 dual, low-dropout linear regulators operate from a +2.5V to +5.5V input range and deliver up to 100mA. At 200mA total load, the PMOS pass transistors keep the supply current at 145µA, making these devices ideal for battery-operated portable equipment such as cellular phones, cordless phones, and modems. ♦ Low Cost The devices feature Dual Mode™ operation: their output voltages are preset (at 3.15V for the “T” versions, 2.84V for the “S” versions, or 2.80V for the “R” versions) or can be adjusted with external resistor dividers. Other features include independent low-power shutdown, short-circuit protection, thermal shutdown protection, and reverse battery protection. The MAX8866 also includes an auto-discharge function, which actively discharges the selected output voltage to ground when the device is placed in shutdown mode. Both devices come in a miniature 8-pin µMAX package. ♦ Low, 350µVRMS Output Noise ♦ Low, 55mV Dropout Voltage @ 50mA IOUT ♦ Low, 105µA No-Load Supply Current ♦ Low, 145µA Operating Supply Current (even in dropout) ♦ Independent, Low-Current Shutdown Control ♦ Thermal Overload Protection ♦ Output Current Limit ♦ Reverse Battery Protection ♦ Dual Mode Operation: Fixed or Adjustable (1.25V to 5.5V) Outputs ______________Ordering Information ________________________Applications Cordless Telephones Modems PCS Telephones Hand-Held Instruments TEMP. RANGE PINPACKAGE PRESET VOUT (V) -40°C to +85°C 8 µMAX 3.15 MAX8865SEUA -40°C to +85°C 8 µMAX 2.84 MAX8865REUA -40°C to +85°C 8 µMAX 2.80 MAX8866TEUA -40°C to +85°C 8 µMAX 3.15 PART MAX8865TEUA Cellular Telephones Palmtop Computers PCMCIA Cards Electronic Planners __________Typical Operating Circuit MAX8866SEUA -40°C to +85°C 8 µMAX 2.84 MAX8866REUA -40°C to +85°C 8 µMAX 2.80 __________________Pin Configuration TOP VIEW OUTPUT VOLTAGE 1 OUT1 IN CIN 2µF BATTERY OUT2 MAX8865 MAX8866 SHDN1 SHDN2 GND SET1 SET2 OUTPUT VOLTAGE 2 COUT1 1µF COUT2 1µF OUT1 1 8 SET1 IN 2 7 SHDN1 6 SHDN2 5 SET2 GND 3 MAX8865 MAX8866 OUT2 4 µMAX SHDN2 Dual Mode is a trademark of Maxim Integrated Products. ________________________________________________________________ Maxim Integrated Products 1 For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800 MAX8865T/S/R, MAX8866T/S/R _______________General Description MAX8865T/S/R, MAX8866T/S/R Dual, Low-Dropout, 100mA Linear Regulators ABSOLUTE MAXIMUM RATINGS VIN to GND ..................................................................-6V to +6V Output Short-Circuit Duration ............................................Infinite SET_ to GND ............................................................-0.3V to +6V SHDN_ _ to GND ............................................................-6V to +6V SHDN_ _ to IN .............................................................-6V to +0.3V OUT_ to GND...............................................-0.3V to (VIN + 0.3V) Continuous Power Dissipation (TA = +70°C) µMAX (derate 4.1mW/°C above +70°C)......................330mW Operating Temperature Range ...........................-40°C to +85°C Junction Temperature ......................................................+150°C Thermal Resistance (θJA)...............................................244°C/W Storage Temperature Range .............................-65°C to +160°C Lead Temperature (soldering, 10sec) .............................+300°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 = +3.6V, GND = 0V, TA = 0°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER Input Voltage (Note 1) SYMBOL Output Voltage VOUT_ Adjustable Output Voltage Range (Note 2) VOUT_ Maximum Output Current Current Limit (Note 3) ILIM Ground Pin Current CONDITIONS MIN VIN MAX886_T MAX886_S MAX886_R 0mA ≤ IOUT ≤ 50mA, SET_ = GND 2.5 3.08 2.77 2.73 TYP MAX UNITS V 3.15 2.84 2.80 5.5 3.24 2.91 2.87 5.5 V VSET_ 100 IQ SET_ = GND 120 0 0.10 SET_ = GND 0.012 0.03 SET_ tied to OUT_ 0.006 IOUT = 1mA IOUT = 50mA Dropout Voltage (Note 4) Line Regulation ∆VLNR VIN = 2.5V to 5.5V, SET_ tied to OUT_, IOUT_ = 1mA Load Regulation ∆VLDR IOUT_ = 0mA to 50mA Output Voltage Noise 10Hz to 1MHz mA mA 220 105 145 1.1 55 IOUT_ = 0mA IOUT_ = 50mA -0.10 COUT = 1µF 350 COUT = 100µF 220 V 270 µA mV %/V %/mA µVRMS SHUTDOWN SHDN Input Threshold VIH 2.0 VIL SHDN Input Bias Current I SHDN_ _ Shutdown Supply Current IQ SHDN Shutdown to Output Discharge Delay (MAX8866) 0.4 V SHDN_ _ = VIN VOUT_ = 0V COUT = 1µF, no load SET INPUT SET Reference Voltage (Note 2) VSET_ VIN = 2.5V to 5.5V, IOUT_ = 1mA SET Input Leakage Current (Note 2) ISET_ VSET_ = 1.3V THERMAL PROTECTION Thermal Shutdown Temperature Thermal Shutdown Hysteresis 2 TSHDN ∆TSHDN 0 1000 nA 0.16 3000 nA 1 1.222 V ms 1.25 1.276 V 0.015 50 nA 170 20 _______________________________________________________________________________________ °C °C Dual, Low-Dropout, 100mA Linear Regulators (VIN = +3.6V, GND = 0V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 5) PARAMETER Input Voltage (Note 1) Output Voltage SYMBOL VOUT_ Adjustable Output Voltage Range (Note 2) CONDITIONS MIN VIN 0mA ≤ IOUT ≤ 50mA, SET_ = GND Ground Pin Current MAX UNITS 5.5 V MAX886_T 3.05 3.15 3.26 MAX886_S 2.74 2.84 2.93 MAX886_R 2.70 2.80 2.89 VOUT_ VSET_ Maximum Output Current Current Limit (Note 3) TYP 2.5 5.5 80 ILIM IQ Dropout Voltage (Note 4) IOUT_ = 0mA 105 IOUT_ = 50mA 145 1.1 IOUT = 50mA 55 120 0 0.11 SET_ = GND 0.012 0.03 SET_ tied to OUT_ 0.006 ∆VLNR VIN = 2.5V to 5.5V, SET_ tied to OUT_, IOUT_ = 1mA Load Regulation ∆VLDR IOUT_ = 0mA to 50mA Output Voltage Noise mA 270 IOUT = 1mA Line Regulation 10Hz to 1MHz -0.11 V mA 220 SET_ = GND V COUT = 1µF 350 COUT = 100µF 220 µA mV %/V %/mA µVRMS SHUTDOWN SHDN Input Threshold VIH 2.0 VIL SHDN Input Bias Current I SHDN_ _ Shutdown Supply Current IQ SHDN Shutdown to Output Discharge Delay (MAX8866) V 0.4 V SHDN_ _ = VIN 0 1000 nA VOUT_ = 0V 0.16 3000 nA COUT = 1µF 1 ms SET INPUT SET Reference Voltage (Note 2) VSET_ VIN = 2.5V to 5.5V, IOUT_ = 1mA SET Input Leakage Current (Note 2) ISET_ VSET_ = 1.3V 1.207 1.25 1.288 V 0.015 50 nA THERMAL PROTECTION Thermal Shutdown Temperature Thermal Shutdown Hysteresis Note 1: Note 2: Note 3: Note 4: Note 5: TSHDN 170 °C ∆TSHDN 20 °C Guaranteed by line regulation test. Adjustable mode only. Not tested. For design purposes, the current limit should be considered 120mA minimum to 320mA maximum. The dropout voltage is defined as (VIN_ - VOUT_) when VOUT_ is 100mV below the value of VOUT_ for VIN_ = VOUT_ +2V. Specifications to -40°C are guaranteed by design and not production tested. _______________________________________________________________________________________ 3 MAX8865T/S/R, MAX8866T/S/R ELECTRICAL CHARACTERISTICS __________________________________________Typical Operating Characteristics (VIN = +3.6V, CIN = 2µF, COUT = 1µF, SHDN2 = GND, MAX886_S, TA = +25°C, unless otherwise noted.) SUPPLY CURRENT vs. LOAD CURRENT 2.90 2.85 2.80 10 20 30 40 50 60 70 80 90 100 0.5 0 0 0 10 20 30 40 50 60 70 80 90 100 3 4 OUTPUT VOLTAGE vs. TEMPERATURE ILOAD1 = 0mA 50 40 30 ILOAD1 = ILOAD2 = 50mA 160 140 ILOAD1 = ILOAD2 = 0mA 120 100 80 60 20 40 10 20 0 0 2 3 4 5 60 80 2.9 2.8 2.7 0 6 6 MAX8865/66-06 SHDN1 = SHDN2 = VIN 180 5 3.0 MAX8865/66-05 MAX8865/66-04 200 SUPPLY CURRENT (µA) 60 1 2 4 3 5 6 -40 -20 0 20 40 INPUT VOLTAGE (V) INPUT VOLTAGE (V) TEMPERATURE (°C) SUPPLY CURRENT vs. TEMPERATURE DROPOUT VOLTAGE vs. LOAD CURRENT POWER-SUPPLY REJECTION RATIO vs. FREQUENCY 120 100 SHDN2 = GND ILOAD1 = 50mA 100 80 60 TA = -40°C 20 40 TEMPERATURE (°C) 60 80 COUT = 10µF 50 40 30 COUT = 1µF 40 20 10 0 0 VOUT = 2.84V RL = 55Ω 60 TA = +25°C 20 60 70 PSRR (dB) SHDN2 = VIN ILOAD1 = ILOAD2 = 50mA 80 MAX8865/66-09 120 DROPOUT VOLTAGE (mV) 160 TA = +85°C MAX8865/66-08 140 MAX8865/66-07 180 -20 2 TOTAL SUPPLY CURRENT vs. INPUT VOLTAGE ILOAD1 = 50mA -40 1 SUPPLY CURRENT vs. INPUT VOLTAGE 70 140 1.0 INPUT VOLTAGE (V) 80 1 1.5 LOAD CURRENT (mA) ONE REGULATOR ENABLED, NO LOAD 0 2.0 LOAD CURRENT (mA) 100 90 2.5 SHDN2 = GND OUTPUT VOLTAGE (V) 0 SUPPLY CURRENT (µA) 100 60 2.70 4 120 80 2.75 80 SHDN2 = VIN, ILOAD2 = 50mA 140 VOUT1 NO LOAD 3.0 OUTPUT VOLTAGE (V) 160 SUPPLY CURRENT (µA) 2.95 3.5 MAX8865/66-02 VOUT1 OUTPUT VOLTAGE (V) 180 MAX8865/66-01 3.00 OUTPUT VOLTAGE vs. INPUT VOLTAGE MAX8865/66-03 OUTPUT VOLTAGE vs. LOAD CURRENT SUPPLY CURRENT (µA) MAX8865T/S/R, MAX8866T/S/R Dual, Low-Dropout, 100mA Linear Regulators 0 0 10 20 30 40 50 60 70 80 90 100 LOAD CURRENT (mA) 0.01 0.10 1 10 100 FREQUENCY (kHz) _______________________________________________________________________________________ 1000 Dual, Low-Dropout, 100mA Linear Regulators (VIN = +3.6V, CIN = 2µF, COUT = 1µF, SHDN2 = GND, MAX886_S, TA = +25°C, unless otherwise noted.) RL = 55Ω 1000 MAX8865/66-11 10 REGION OF STABLE COUT ESR vs. LOAD CURRENT MAX8865/66-10 COUT = 1µF 100 COUT = 1µF 1 COUT ESR (Ω) OUTPUT SPECTRAL NOISE DENSITY (µV/Hz) OUTPUT SPECTRAL NOISE DENSITY vs. FREQUENCY COUT = 100µF 0.1 10 INTERNAL FEEDBACK 1 EXTERNAL FEEDBACK 0.1 0.01 STABLE REGION 0.01 0.1 1 10 100 1000 0 FREQUENCY (kHz) 10 20 30 40 50 60 70 80 90 100 LOAD CURRENT (mA) OUTPUT NOISE DC TO 1MHz VOUT 1ms/div ILOAD = 50mA, VOUT IS AC COUPLED LOAD-TRANSIENT RESPONSE LINE-TRANSIENT RESPONSE 4.6V VIN 50mA ILOAD 3.6V 0mA 2.84V 2.85V VOUT 2.83V VOUT 2.84V 2.82V 2.83V 50µs/div ILOAD = 50mA, VOUT IS AC COUPLED 10µs/div VIN = 3.60V, ILOAD = 0mA to 50mA, CIN = 10µF, VOUT IS AC COUPLED _______________________________________________________________________________________ 5 MAX8865T/S/R, MAX8866T/S/R ____________________________Typical Operating Characteristics (continued) MAX8865T/S/R, MAX8866T/S/R Dual, Low-Dropout, 100mA Linear Regulators ____________________________Typical Operating Characteristics (continued) (VIN = +3.6V, CIN = 2µF, COUT = 1µF, SHDN2 = GND, MAX886_S, TA = +25°C, unless otherwise noted.) LOAD-TRANSIENT RESPONSE LOAD-TRANSIENT RESPONSE 50mA 50mA ILOAD ILOAD 0mA 0mA 2.85V 2.85V VOUT 2.84V VOUT 2.84V 2.83V 2.83V 10µs/div VIN = VOUT + 0.1V, ILOAD = 0mA to 50mA, CIN = 10µF, VOUT IS AC COUPLED 10µs/div VIN = VOUT + 0.2V, ILOAD = 0mA to 50mA, CIN = 10µF, VOUT IS AC COUPLED CROSSTALK DUE TO LOAD TRANSIENT VOUT1 AC COUPLED (10mV/div) VOUT2 AC COUPLED (50mV/div) ILOAD2 100mA 0mA 20µs/div CIN = 10µF, IOUT1 = 100mA, SHDN2 = VIN MAX8866 SHUTDOWN (50mA LOAD) MAX8866 SHUTDOWN (NO LOAD) 2V 2V VSHDN VSHDN VOUT 0V 0V 4V 4V VOUT 2V 2V 0V 0V 500µs/div NO LOAD 6 500µs/div ILOAD = 50mA _______________________________________________________________________________________ Dual, Low-Dropout, 100mA Linear Regulators PIN NAME FUNCTION 1 OUT1 2 IN 3 GND Ground. Solder to large pads or the circuit board ground plane to maximize thermal dissipation. 4 OUT2 Regulator 2 Output. Fixed or adjustable from 1.25V to 5.5V. Sources up to 100mA. Bypass with a 1µF capacitor to GND. 5 SET2 Feedback Input for Setting the Output 2 Voltage. Connect to GND to set the output voltage to the preset 2.80V (MAX886_R), 2.84V (MAX886_S), or 3.15V (MAX886_T). Connect to an external resistor divider for adjustableoutput operation. 6 SHDN2 Active-Low Shutdown 2 Input. A logic low turns off regulator 2. On the MAX8866, a logic low also causes the output voltage to discharge to GND. Connect to IN for normal operation. 7 SHDN1 Active-Low Shutdown 1 Input. A logic low turns off regulator 1. On the MAX8866, a logic low also causes the output voltage to discharge to GND. Connect to IN for normal operation. 8 SET1 Feedback Input for Setting the Output 1 Voltage. Connect to GND to set the output voltage to the preset 2.80V (MAX886_R), 2.84V (MAX886_S), or 3.15V (MAX886_T). Connect to an external resistor divider for adjustableoutput operation. Regulator 1 Output. Fixed or adjustable from 1.25V to 5.5V. Sources up to 100mA. Bypass with a 1µF capacitor to GND. Regulator Input. Supply voltage can range from +2.5V to +5.5V. Bypass with 2µF to GND. _______________Detailed Description The MAX8865/MAX8866 are dual, low-dropout, low-quiescent-current linear regulators designed primarily for battery-powered applications. They supply adjustable 1.25V to 5.5V outputs or preselected 2.80V (MAX886_R), 2.84V (MAX886_S), or 3.15V (MAX886_T) outputs for load currents up to 100mA. As illustrated in Figure 1, these devices have a 1.25V reference and two independent linear regulators. Each linear regulator consists of an error amplifier, MOSFET driver, P-channel pass transistor, Dual Mode™ comparator, and internal feedback voltage divider. The 1.25V bandgap reference is connected to the error amplifiers’ inverting inputs. Each 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 pass transistor. If the feedback voltage is lower than the reference, the pass-transistor gate is pulled lower, allowing more current to pass and increasing the output voltage. If the feedback voltage is too high, the pass-transistor gate is pulled up, allowing less current to pass to the output. The output voltage is fed back through either an internal resistor voltage divider connected to the OUT_ pin, or an external resistor network connected to the SET_ pin. The Dual Mode comparator examines the SET_ voltage and selects the feedback path. If SET_ is below 60mV, internal feedback is used and the output voltage is regulated to 2.80V for the MAX886_R, 2.84V for the MAX886_S, or 3.15V for the MAX886_T. Both regulators are preset for the same voltage. The reference and the thermal sensor are shared between the regulators. Duplicate blocks exist for current limiters, reverse battery protection, and shutdown logic. Internal P-Channel Pass Transistor The MAX8865/MAX8866 feature 1.1Ω typical P-channel MOSFET pass transistors. This provides several advantages over similar designs using PNP pass transistors, including longer battery life. The P-channel MOSFET requires no base-drive current, which reduces quiescent current significantly. PNPbased regulators waste considerable amounts of current in dropout when the pass transistor saturates. They also use high base-drive currents under large loads. The MAX8865/MAX8866 do not suffer from these problems, and consume only 145µA of quiescent current, whether in dropout, light load, or heavy load applications (see Typical Operating Characteristics). Output Voltage Selection The MAX8865/MAX8866 feature Dual Mode operation: they operate in either a preset voltage mode or an adjustable mode. _______________________________________________________________________________________ 7 MAX8865T/S/R, MAX8866T/S/R ______________________________________________________________Pin Description MAX8865T/S/R, MAX8866T/S/R Dual, Low-Dropout, 100mA Linear Regulators IN SHDN1 REVERSE BATTERY PROTECTION ERROR AMP MAX8865 MAX8866 SHUTDOWN LOGIC N OUT1 * THERMAL SENSOR SET1 1.25V REF DUAL-MODE COMPARATOR SHDN2 P MOS DRIVER WITH ILIMIT 60mV REVERSE BATTERY PROTECTION ERROR AMP P MOS DRIVER WITH ILIMIT SHUTDOWN LOGIC N OUT2 * SET2 DUAL-MODE COMPARATOR 60mV GND * AUTO-DISCHARGE, MAX8866 ONLY Figure 1. Functional Diagram 8 _______________________________________________________________________________________ Dual, Low-Dropout, 100mA Linear Regulators OUT_ IN CIN 2µF MAX8865 MAX8866 SHDN_ R1 COUT 1µF SET_ BATTERY GND 20pF RL Current Limit The MAX8865/MAX8866 include a current limiter for each output section that monitors and controls the pass transistor’s gate voltage, estimating the output current and limiting it to about 220mA. For design purposes, the current limit should be considered 120mA (min) to 320mA (max). The outputs can be shorted to ground for an indefinite time period without damaging the part. R2 Figure 2. Adjustable Output Using External Feedback Resistors In preset voltage mode, internal, trimmed feedback resistors set the MAX886_R outputs to 2.80V, the MAX886_S outputs to 2.84V, and the MAX886_T outputs to 3.15V. Select this mode by connecting SET_ to ground. If SET_ can’t be grounded in preset voltage mode, limit impedances between SET_ and ground to less than 100kΩ. Otherwise, spurious conditions could cause the voltage at SET_ to exceed the 60mV Dual Mode threshold. In adjustable mode, select an output between 1.25V and 5.5V using two external resistors connected as a voltage divider to SET_ (Figure 2). The output voltage is set by the following equation: VOUT_ = VSET_ (1 + R1 / R2) where VSET_ = 1.25V. To simplify resistor selection: VOUT _ R1 = R2 − 1 VSET _ Thermal Overload Protection Thermal overload protection limits total power dissipation in the MAX8865/MAX8866. When the junction temperature exceeds TJ = +170°C, the thermal sensor sends a signal to the shutdown logic, turning off the pass transistors and allowing the IC to cool. The thermal sensor will turn the pass transistors on again after the IC’s junction temperature typically cools by 20°C, resulting in a pulsed output during continuous thermal overload conditions. Thermal overload protection is designed to protect the MAX8865/MAX8866 in the event of fault conditions. Stressing the device with high load currents and high input-output differential voltages (which result in elevated die temperatures above +125°C) may cause a momentary overshoot (2% to 8% for 200ms) when the load is completely removed. This can be remedied by raising the minimum load current from 0µA (+125°C) to 100µA (+150°C). For continuous operation, do not exceed the absolute maximum junction temperature rating of TJ = +150°C. Operating Region and Power Dissipation Choose R2 = 100kΩ to optimize power consumption, accuracy, and high-frequency power-supply rejection. The total current through the external resistive feedback and load resistors should not be less than 10µA. Since the VSET_ tolerance is typically less than ±25mV, the output can be set using fixed resistors instead of trim pots. Connect a 10pF to 25pF capacitor across R1 to compensate for layout-induced parasitic capacitances. Shutdown A low input on a SHDN_ _ pin individually shuts down one of the two outputs. In shutdown mode, the selected pass transistor, control circuit, and all biases are turned Maximum power dissipation of the MAX8865/MAX8866 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 - TA) / θJA where (TJ - TA) is the temperature difference between the MAX8865/MAX8866 die junction and the surrounding air, and θJA is the thermal resistance of the package to the surrounding air (244°C/W). _______________________________________________________________________________________ 9 MAX8865T/S/R, MAX8866T/S/R OUTPUT VOLTAGE off. When both sections are turned off, the reference and thermal shutdown are also turned off and the supply current is typically reduced to 0.16nA. Connect SHDN_ _ to IN for normal operation. The MAX8866 output voltages are actively discharged to ground when individual regulators are shut down (see Typical Operating Characteristics). MAX8865T/S/R, MAX8866T/S/R Dual, Low-Dropout, 100mA Linear Regulators Reverse Battery Protection The MAX8865/MAX8866 have a unique protection scheme that limits the reverse supply current to less than 1mA when either V IN or V SHDN_ _ falls below ground. The circuitry monitors the polarity of these pins, disconnecting the internal circuitry and parasitic diodes when the battery is reversed. This feature prevents the device from overheating and damaging the battery. __________Applications Information Capacitor Selection and Regulator Stability Normally, use two 1µF surface-mount ceramic capacitors on the input and a 1µF surface-mount ceramic capacitor on each output of the MAX8865/MAX8866. Larger input capacitor values and lower ESR provide better supply-noise rejection and transient response. A higher-value input capacitor (10µF) may be necessary if large, fast transients are anticipated and the device is located several inches from the power source. Improve load-transient response, stability, and power-supply rejection by using large output capacitors. For stable operation over the full temperature range, with load currents of 100mA, a minimum of 1µF is recommended (see the Region of Stable COUT ESR vs. Load Current graph in the Typical Operating Characteristics). Noise The MAX8865/MAX8866 exhibit 350µVRMS noise during normal operation. When using the MAX8865/MAX8866 in applications that include analog-to-digital converters of greater than 12 bits, consider the ADC’s power-supply rejection specifications (see the Output Noise DC to 1MHz photo in the Typical Operating Characteristics). Power-Supply Rejection and Operation from Sources Other than Batteries The MAX8865/MAX8866 are designed to deliver low dropout voltages and low quiescent currents in batterypowered systems. Power-supply rejection is 60dB at low frequencies and rolls off above 400Hz. As the frequency increases above 100kHz, the output capacitor is the major contributor to the rejection of power-supply noise 10 (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 capacitors, and using passive filtering techniques (see the supply and load-transient responses in the Typical Operating Characteristics). Load-Transient Considerations The MAX8865/MAX8866 load-transient response graphs (see Typical Operating Characteristics) show two components of the output response: a DC shift of the output voltage due to the different load currents, and the transient response. Typical overshoot for step changes in the load current from 0mA to 50mA is 12mV. Increasing the output capacitor’s value and decreasing its ESR attenuates transient spikes. Cross-Regulation Cross-regulation refers to the change in one output voltage when the load changes on the other output. For the MAX8865/MAX8866, cross-regulation for a 0mA to 50mA load change on one side results in less than 1mV change of output voltage. If the power dissipation on one output causes the junction temperature to exceed 125°C, ensure regulation of the other output with a minimum load current of 100µA. 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 will determine the useful end-of-life battery voltage. Because the MAX8865/MAX8866 use P-channel MOSFET pass transistors, their dropout voltages are a function of RDS(ON) multiplied by the load currents (see Electrical Characteristics). ___________________Chip Information TRANSISTOR COUNT: 259 ______________________________________________________________________________________ Dual, Low-Dropout, 100mA Linear Regulators DIM C α A 0.101mm 0.004 in e B A1 L A A1 B C D E e H L α INCHES MAX MIN 0.044 0.036 0.008 0.004 0.014 0.010 0.007 0.005 0.120 0.116 0.120 0.116 0.0256 0.198 0.188 0.026 0.016 6° 0° MILLIMETERS MIN MAX 0.91 1.11 0.10 0.20 0.25 0.36 0.13 0.18 2.95 3.05 2.95 3.05 0.65 4.78 5.03 0.41 0.66 0° 6° 21-0036D E H 8-PIN µMAX MICROMAX SMALL-OUTLINE PACKAGE D ______________________________________________________________________________________ 11 MAX8865T/S/R, MAX8866T/S/R ________________________________________________________Package Information MAX8865T/S/R, MAX8866T/S/R Dual, Low-Dropout, 100mA Linear Regulators 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. 12 __________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600 © 1996 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.