MAX1857 19-1812 Rev 0 1/01 500mA, Low-Dropout, Ripple-Rejecting LDO in MAX General Description Features The MAX1857 low-dropout linear regulator operates Guaranteed 500mA Output Current from a +2.5V to +5.5V supply and delivers a guaran- Low 120mV Dropout at 500mA teed 500mA load current with low 120mV dropout. The high-accuracy (1%) output voltage is preset at an Up to 1% Output Voltage Accuracy internally trimmed 4.75V or can be adjusted from 1.25V Preset at 4.75V to 5.0V with an external resistive divider. Adjustable from 1.25V to 5.0V An internal PMOS pass transistor allows the low 135A supply current to remain independent of load, making Reset Output with 4.5ms Timeout Period this device ideal for portable battery-operated equip- Low 135A Ground Current ment such as personal digital assistants (PDAs), cellu- lar phones, cordless phones, base stations, and 0.1A Shutdown Current notebook computers. Thermal Overload Protection Other features include an active-low open-drain reset output with a 4.5ms timeout period that indicates when Output Current Limit the output is out of regulation, a 0.1A shutdown mode, Tiny MAX Package short-circuit protection, and thermal shutdown protec- tion. The device is available in a miniature 8-pin MAX package. For higher power applications, refer to the MAX1792 and MAX1793 data sheets. Applications Ordering Information Notebook Computers PART* TEMP. RANGE PIN-PACKAGE Cellular and Cordless Telephones MAX1857EUA47 -40C to +85C 8 MAX PDAs *Contact factory for other preset output voltages. Palmtop Computers Base Stations USB Hubs Docking Stations Typical Operating Circuit Pin Configuration TOP VIEW V = +5V V = 4.75V IN OUT IN OUT NC C C OUT IN IN OUT 3.3 F IN 1 8 OUT 1 F IN 2 7 OUT R RST MAX1857 MAX1857 100k RST 3 6 SET ON TO SHDN RST C SHDN 4 5 GND OFF MAX SET GND Maxim Integrated Products 1 For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com.500mA, Low-Dropout, Ripple-Rejecting LDO in MAX ABSOLUTE MAXIMUM RATINGS IN, SHDN, RST, SET to GND....................................-0.3V to +6V Operating Temperature Range ...........................-40C to +85C OUT to GND ................................................-0.3V to (V + 0.3V) Junction Temperature......................................................+150C IN Output Short-Circuit Duration ........................................Indefinite Storage Temperature Range .............................-65C to +150C Continuous Power Dissipation (T = +70C) Lead Temperature (soldering, 10s) .................................+300C A 8-Pin MAX (derate 4.5mW/C above +70C) .............362mW 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 (V = +5.25V, V = 4.75V, SHDN = IN, SET = GND, T = 0C to +85C, unless otherwise noted. Typical values are at T = +25C.) IN OUT A A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Input Voltage V 2.5 5.5 V IN Input Undervoltage Lockout V Rising, 75mV hysteresis 2.0 2.15 2.3 V UVLO V 2.5V -1 +1 I = 100mA, OUT OUT % T = +85C A V < 2.5V -1.5 +1.5 OUT Output Voltage Accuracy V I = 100mA, T = 0C to +85C-2 +2 OUT OUT A (Preset Mode) % I = 1mA to 500mA, V > V OUT IN OUT + 0.5V, -3 +3 T A = 0C to +85C Adjustable Output Voltage V = 1.25V 1.25 5V SET Range V = +2.7V, T = +85C 1.229 1.250 1.271 IN A SET Voltage Threshold V V set to 2.0V, V SET OUT (Adjustable Mode) T = 0C to +85C 1.219 1.281 I = 100mA OUT A Maximum Output Current I V 2.7V 500 mA OUT IN RMS Short-Circuit Current Limit I V = 0, V 2.7V 0.55 1.2 2.2 A LIM OUT IN In-Regulation Current Limit V > 96% of nominal value, V 2.7V 2.0 A OUT IN SET Dual Mode Threshold 50 100 150 mV SET Input Bias Current I V = 1.25V -100 +100 nA SET SET I = 1mA 135 250 OUT Ground-Pin Current I A Q I = 500mA 175 OUT V - IN Dropout Voltage (Note 1) I = 500mA 120 175 mV OUT V OUT V from (V + 100mV) to 5.5V, IN OUT Line Regulation V -0.15 0 +0.15 %/V LNR I = 5mA LOAD Load Regulation V I = 1mA to 500mA 0.4 1.0 % LDR OUT Output Voltage Noise 10Hz to 1MHz, C 115 V OUT = 3.3 F (ESR < 0.1 ) RMS SHUTDOWN Shutdown Supply Current I SHDN = GND, V = 5.5V 0.1 15 A OFF IN V 2.5V < V < 5.5V 1.6 IH IN SHDN Input Threshold V V 2.5V < V < 5.5V 0.6 IL IN SHDN Input Bias Current SHDN = IN or GND 10 100 nA Dual Mode is a trademark of Maxim Integrated Products. 2 MAX1857