MAX1820/MAX1821 19-2011 Rev 3 4/05 WCDMA Cellular Phone 600mA Buck Regulators General Description Features The MAX1820/MAX1821 low-dropout, pulse-width-mod- Dynamically Adjustable Output from 0.4V to 3.4V ulated (PWM) DC-DC buck regulators are optimized to (MAX1820) provide power to the power amplifier (PA) in WCDMA Programmable Output from 1.25V to 5.5V cell phones however, they may be applied in many (MAX1821) other applications where high efficiency is a priority. The supply voltage range is from 2.6V to 5.5V, and the guar- SYNC to 13MHz External Clock (MAX1820X) anteed output current is 600mA 1MHz PWM switching SYNC to 19.8MHz External Clock (MAX1820Y) allows for small external components, while skip mode reduces quiescent current to 180A with light loads. NO SYNC, Internal 1MHz Oscillator (MAX1820Z) The MAX1820 is dynamically controlled to provide vary- Low Quiescent Current ing output voltages from 0.4V to 3.4V. The circuit is 180A (typ) in Skip Mode designed such that the output voltage settles in <30s 0.1A (typ) in Shutdown Mode for a full-scale change in voltage and current. The No External Schottky Diode Required MAX1821 is set with external resistors to provide any fixed output voltage in the 1.25V to 5.5V range. 600mA Guaranteed Output Current The MAX1820/MAX1821 include a low on-resistance 0% to 100% Duty-Cycle Operation internal MOSFET switch and synchronous rectifier to 150mV Dropout at 600mA Load (Including R DC maximize efficiency and minimize external component of External Inductor) count 100% duty-cycle operation allows for low dropout of only 150mV at 600mA load, including the external MAX or UCSP Packaging inductor resistance. The devices are offered in 10-pin MAX and tiny 3 4 chip-scale (UCSP) packages. Typical Operating Circuits Applications 4.7H INPUT DYNAMIC WCDMA Cell Phone Power Amplifiers 2.6V TO OUTPUT BATT LX 5.5V 0.4V TO 3.4V PDA, Palmtop, and Notebook Computers SHDN OUT 4.7F Microprocessor Core Supplies PGND Digital Cameras MAX1820 13MHz PCMCIA and Network Cards SYNC COMP OR 19.8MHz Hand-Held Instruments V CONTROL OUT REF DAC Typical Operating Circuits continued at end of data sheet. SKIP GND Ordering Information continued at end of data sheet. Pin Configurations appear at end of data sheet. UCSP is a trademark of Maxim Integrated Products, Inc. MAX is a registered trademark of Maxim Integrated Products, Inc. Ordering Information SYNC PART OUTPUT VOLTAGE TEMP RANGE PIN-PACKAGE UCSP MARK FREQ (MHz) No Sync MAX1820ZEBC* Dynamic -40C to +85C 3 4 UCSP AAB 19.8 MAX1820YEBC* Dynamic -40C to +85C 3 4 UCSP AAL MAX1820XEBC* 13 Dynamic -40C to +85C 3 4 UCSP AAM No Sync MAX1820ZEUB Dynamic -40C to +85C 10 MAX 19.8 MAX1820YEUB Dynamic -40C to +85C 10 MAX MAX1820XEUB 13 Dynamic -40C to +85C 10 MAX *UCSP reliability is integrally linked to the users assembly methods, circuit board material, and environment. See the UCSP Reliability Notice in the UCSP Reliability section of this data sheet for more information. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com. EVALUATION KIT AVAILABLEWCDMA Cellular Phone 600mA Buck Regulators ABSOLUTE MAXIMUM RATINGS Operating Temperature Range ...........................-40C to +85C BATT, OUT (FB), SHDN, SYNC, SKIP, Junction Temperature......................................................+150C REF to GND.......................................................-0.3V to +6.0V PGND to GND .......................................................-0.3V to +0.3V Storage Temperature Ranges 3 4 UCSP ....................................................-40C to +150C LX, COMP to GND...................................-0.3V to (V + 0.3V) BATT Output Short-Circuit Duration ............................................Infinite 10-Pin MAX ..................................................-65C to +150C Solder Profile (UCSP) ......................................................(Note 1) Continuous Power Dissipation (T = +70C) A Lead Temperature (soldering, 10s) .................................+300C 3 4 UCSP (derate 10.4mW/C above +70C)............832mW 10-Pin MAX (derate 5.6mW/C above +70C) ...........444mW Note 1: For UCSP solder profile information, visit www.maxim-ic.com/1st pages/UCSP.htm. 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 = 3.6V, SHDN = BATT, SKIP = SYNC = GND, V = 1.25V (MAX1820 only), T = 0C to +85C, unless otherwise noted. BATT REF A Typical values are at T = +25C.) (Note 2) A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Input BATT Voltage V 2.6 5.5 V IN Undervoltage Lockout V V rising, 1% hysteresis 2.20 2.35 2.55 V UVLO BATT Threshold SKIP = GND (MAX1820Z/MAX1821) 180 300 SKIP = BATT, no switching 450 2000 Quiescent Current I A Q SKIP = GND (MAX1820Y, MAX1820X, and 240 360 MAX1821X) SKIP = BATT, 1MHz switching 3300 SKIP = GND 530 1000 Quiescent Current in Dropout A SKIP = BATT, no switching 550 1000 Shutdown Supply Current I SHDN = GND 0.1 6 A SHDN ERROR AMPLIFIER V = 1.932 0.005V, load = 0 to 600mA, REF 3.33 3.4 3.47 SKIP = BATT or GND OUT Voltage Accuracy V V OUT (MAX1820) V = 0.227 0.005V, load = 0 to 30mA, REF 0.35 0.40 0.45 SKIP = BATT, V 4.2V BATT OUT Input Resistance R 250 400 k OUT (MAX1820) REF Input Current (MAX1820) I 0.1 1 A REF FB Voltage Accuracy V FB = COMP 1.225 1.25 1.275 V FB (MAX1821) FB Input Current (MAX1821) I V = 1.4V 0.01 50 nA FB FB Transconductance g 30 50 85 S m COMP Clamp Low Voltage 0.2 0.45 1.0 V COMP Clamp High Voltage 2.04 2.15 2.28 V 2 MAX1820/MAX1821