EVALUATION KIT AVAILABLE MAX8640Y/MAX8640Z Tiny 500mA, 4MHz/2MHz Synchronous Step-Down DC-DC Converters General Description Features Tiny SC70 and DFN Packages The MAX8640Y/MAX8640Z step-down converters are optimized for applications where small size, high effi- 500mA Guaranteed Output Current ciency, and low output ripple are priorities. They utilize 4MHz or 2MHz PWM Switching Frequency a proprietary PWM control scheme that optimizes the Tiny External Components: 1H/2.2F or switching frequency for high efficiency with small exter- 2.2H/4.7F nal components and maintains low output ripple volt- 28A Quiescent Current age at all loads. The MAX8640Z switches at up to Factory Preset Outputs from 0.8V to 2.5V 4MHz to allow a tiny 1H inductor and 2.2F output 1% Initial Accuracy capacitor. The MAX8640Y switches at up to 2MHz for Low Output Ripple at All Loads higher efficiency while still allowing small 2.2H and Ultrasonic Skip Mode Down to 1mA Loads 4.7F components. Output current is guaranteed up to Ultra-Fast Line- and Load-Transient Response 500mA, while typical quiescent current is 28A. Factory-preset output voltages from 0.8V to 2.5V elimi- Fast Soft-Start Eliminates Inrush Current nate external feedback components. Ordering Information Internal synchronous rectification greatly improves effi- PIN- ciency and replaces the external Schottky diode PART* TOP MARK PACKAGE required in conventional step-down converters. Internal fast soft-start eliminates inrush current so as to reduce MAX8640YEXT08+T 6 SC70 ACQ input capacitor requirements. MAX8640YEXT10+T 6 SC70 ADF The MAX8640Y/MAX8640Z are available in the tiny 6- MAX8640YEXT11+T 6 SC70 ACR pin, SC70 (2.0mm x 2.1mm) and DFN (1.5mm x MAX8640YEXT12+T 6 SC70 ACS 1.0mm) packages. Both packages are lead-free. MAX8640YEXT13+T 6 SC70 ACG Applications MAX8640YEXT15+T 6 SC70 ADD Microprocessor/DSP Core Power MAX8640YEXT16+T 6 SC70 ADB MAX8640YEXT18+T 6 SC70 ACI I/O Power MAX8640YEXT19+T 6 SC70 ACH Cell Phones, PDAs, DSCs, MP3s MAX8640YEXT82+T 6 SC70 ADJ Other Handhelds Where Space Is Limited *Contact factory for availability of each version. For 2.85V output (82 version), request application note that includes limitations and typical operating characteristics. +Denotes a lead(Pb)-free/RoHS-compliant package. T = Tape and reel. Note: All devices are specified over the -40C to +85C operating temperature range. Ordering Information continued and Selector Guide appears at end of data sheet. Pin Configurations Typical Operating Circuit TOP VIEW OUTPUT + L1 + INPUT 0.8V TO 2.5V 1H OR 2.2H 2.7V TO 5.5V UP TO 500mA IN 6 IN LX 1 6 1 LX IN LX MAX8640Y C1 MAX8640Y MAX8640Y MAX8640Z 2.2F 2 MAX8640Z 5 GND MAX8640Z GND 2 5 GND GND GND OUT C2 OUT 3 4 SHDN OUT SHDN 3 4 2.2F OR 4.7F ON/OFF SHDN SC70 DFN 2.0mm x 2.1mm 1.5mm x 1.0mm For pricing, delivery, and ordering information, please contact Maxim Direct 19-3997 Rev 5 8/14 at 1-888-629-4642, or visit Maxims website at www.maximintegrated.com.MAX8640Y/MAX8640Z Tiny 500mA, 4MHz/2MHz Synchronous Step-Down DC-DC Converters ABSOLUTE MAXIMUM RATINGS IN to GND.................................................................-0.3V to +6V 6-Pin DFN (derate 2.1mW/C above +70C) ..............167.7mW OUT, SHDN to GND ....................................-0.3V to (V + 0.3V) Operating Temperature Range ...........................-40C to +85C IN LX Current (Note 1) ........................................................0.8A Junction Temperature......................................................+150C RMS OUTPUT Short Circuit to GND ...................................Continuous Storage Temperature Range .............................-65C to +150C Continuous Power Dissipation (T = +70C) Lead Temperature (soldering, 10s) .................................+300C A 6-Pin SC70 (derate 3.1mW/C above +70C)..............245mW Note 1: LX has internal clamp diodes to IN and GND. Applications that forward bias these diodes should not exceed the ICs package power-dissipation limit. 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 = IN, T = -40C to +85C, typical values are at T = +25C, unless otherwise noted.) (Note 2) IN A A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Range V 2.7 5.5 V IN UVLO Threshold UVLO V rising, 100mV hysteresis 2.44 2.6 2.70 V IN No load, no switching 28 48 Supply Current I T = +25C 0.01 0.1 A CC A SHDN = GND T = +85C 0.1 A Output Voltage Range V Factory preset 0.8 2.5 V OUT I = 0mA, T = +25C -1 0 +1 Output Voltage Accuracy LOAD A % (Falling Edge) I = 0mA, T = -40C to +85C -2 +2 LOAD A Output Load Regulation Equal to inductor DC resistance R V/A L (Voltage Positioning) V V = 2.7V to 5.5V 1.4 IH IN SHDN Logic Input Level V V V = 2.7V to 5.5V 0.4 IL IN T = +25C 0.001 1 V = 5.5V, A IN SHDN Input Bias Current I A IH,IL SHDN = GND or IN T = +85C 0.01 A Minimum Required SHDN Reset t 10 s SHDN Time Peak Current Limit I pFET switch 590 770 1400 mA LIMP Valley Current Limit I nFET rectifier 450 650 1300 mA LIMN Rectifier Off-Current Threshold I nFET rectifier 10 40 70 mA LXOFF R pFET switch, I = -40mA 0.6 1.2 ONP LX On-Resistance R nFET rectifier, I = 40mA 0.35 0.7 ONN LX T = +25C 0.1 1 V = 5.5V, LX = GND A IN LX Leakage Current I A LXLKG to IN, SHDN = GND T = +85C 1 A t 95 ON(MIN) Minimum On and Off Times ns t 95 OFF(MIN) Thermal Shutdown +160 C Thermal-Shutdown Hysteresis 20 C Note 2: All devices are 100% production tested at T = +25C. Limits over the operating temperature range are guaranteed by design. A 2 Maxim Integrated