MAX668/MAX669 1.8V to 28V Input, PWM Step-Up Controllers in MAX General Description Benefits and Features The MAX668/MAX669 constant-frequency, pulse-width- 1.8V Minimum Start-Up Voltage (MAX669) modulating (PWM), current-mode DC-DC controllers are Wide Input Voltage Range (1.8V to 28V) designed for a wide range of DC-DC conversion applications Tiny 10-Pin MAX Package including step-up, SEPIC, flyback, and isolated-output configurations. Power levels of 20W or more can be Current-Mode PWM and Idle Mode Operation controlled with conversion efficiencies of over 90%. The Efficiency over 90% 1.8V to 28V input voltage range supports a wide range of Adjustable 100kHz to 500kHz Oscillator or battery and AC-powered inputs. An advanced BiCMOS SYNC Input design features low operating current (220A), adjustable 220A Quiescent Current operating frequency (100kHz to 500kHz), soft-start, and a SYNC input allowing the MAX668/MAX669 oscillator to Logic-Level Shutdown be locked to an external clock. Soft-Start DC-DC conversion efficiency is optimized with a low Applications 100mV current-sense voltage as well as with Maxims proprietary Idle Mode control scheme. The controller Cellular Telephones operates in PWM mode at medium and heavy loads for Telecom Hardware lowest noise and optimum efficiency, then pulses only as LANs and Network Systems needed (with reduced inductor current) to reduce operating POS Systems current and maximize efficiency under light loads. A logic- Ordering Information level shutdown input is also included, reducing supply current to 3.5A. PART TEMP RANGE PIN-PACKAGE MAX668EUB -40C to +85C 10 MAX The MAX669, optimized for low input voltages with a guaranteed start-up voltage of 1.8V, requires bootstrapped MAX669EUB -40C to +85C 10 MAX operation (IC powered from boosted output). It supports MAX669EUB/V+T -40C to +85C 10 MAX output voltages up to 28V. The MAX668 operates with Idle Mode is a trademark of Maxim Integrated Products. inputs as low as 3V and can be connected in either a boot- + Denotes a lead(Pb)-free/RoHS-compliant package. strapped or non-bootstrapped (IC powered from input sup- T = Tape and reel. ply or other source) configuration. When not bootstrapped, /V Denotes an automotive qualified part. it has no restriction on output voltage. Both ICs are avail- Note: Devices are also available in a lead(Pb)-free/RoHS- able in an extremely compact 10-pin MAX package. compliant package. Specify lead-free by adding + to the part number when ordering. Typical Operating Circuit Pin Configuration V = 1.8V to 28V IN TOP VIEW V = 28V OUT V CC SYNC/ EXT SHDN LDO 1 10 SYNC/SHDN FREQ CS+ FREQ 2 9 V CC MAX668 MAX669 MAX669 GND 3 8 EXT REF 4 7 PGND LDO PGND FB 5 6 CS+ FB REF MAX GND 19-4778 Rev 3 6/16MAX668/MAX669 1.8V to 28V Input, PWM Step-Up Controllers in MAX Absolute Maximum Ratings V to GND ..........................................................-0.3V to +30V Continuous Power Dissipation (T = +70C) CC A PGND to GND ....................................................................0.3V 10-Pin MAX (derate 5.6mW/C above +70C) .........444mW SYNC/SHDN to GND ............................................-0.3V to +30V Operating Temperature Range ........................... -40C to +85C EXT, REF to GND .................................. -0.3V to (V + 0.3V) Junction Temperature ......................................................+150C LDO LDO, FREQ, FB, CS+ to GND ................................-0.3V to +6V Storage Temperature Range ............................ -65C to +150C LDO Output Current ........................................... -1mA to +20mA Lead Temperature (soldering,10sec) ...............................+300C REF Output Current ............................................. -1mA to +1mA Soldering Temperature (Reflow) ......................................+300C LDO Short Circuit to GND .........................................Momentary Lead(Pb)-Free Packages ................................................+260C REF Short Circuit to GND .........................................Continuous Packages Containing Lead(Pb).......................................+240C Electrical Characteristics (V = V = +5V, R = 200k, T = 0C to +85C, unless otherwise noted. Typical values are at T = +25C.) CC LDO OSC A A PARAMETER CONDITIONS MIN TYP MAX UNITS PWM CONTROLLER MAX668 3 28 Input Voltage Range, V V CC MAX669 1.8 28 Input Voltage Range with V Tied to LDO 2.7 5.5 V CC FB Threshold 1.225 1.250 1.275 V Typically 0.013% per mV on CS+ FB Threshold Load Regulation V + range is 0 to 100mV for 0 to full load 0.013 %/mV CS current. Typically 0.012% per % duty factor on FB Threshold Line Regulation EXT EXT duty factor for a step-up is: 0.012 %/% 100% (1 V /V ) IN OUT FB Input Current V = 1.30V 1 20 nA FB Current Limit Threshold 85 100 115 mV Idle Mode Current-Sense Threshold 5 15 25 mV CS+ Input Current CS+ forced to GND 0.2 1 A V Supply Current (Note 1) V = 1.30V, V = 3V to 28V 220 350 A CC FB CC Shutdown Supply Current (V ) SYNC/SHDN = GND, V = 28V 3.5 6 A CC CC REFERENCE AND LDO REGULATORS 5V V 28V CC 4.50 5.00 5.50 (includes LDO dropout) LDO load = LDO Output Voltage V to 400 3V V 28V CC 2.65 5.50 (includes LDO dropout) Sensed at LDO, falling edge, Undervoltage Lockout Threshold 2.40 2.50 2.60 V hysteresis = 1%, MAX668 only REF Output Voltage No load, C = 0.22F 1.225 1.250 1.275 V REF REF Load Regulation REF load = 0 to 50A -2 -10 mV REF Undervoltage Lockout Threshold Rising edge, 1% hysteresis 1.0 1.1 1.2 V OSCILLATOR R = 200k 1% 225 250 275 OSC Oscillator Frequency R = 100k 1% 425 500 575 kHz OSC R = 500k 1% 85 100 115 OSC Maxim Integrated 2 www.maximintegrated.com