MAX1703 19-1336 Rev 2 11/98 1-Cell to 3-Cell, High-Power (1.5A), Low-Noise, Step-Up DC-DC Converter General Description Features The MAX1703 is a high-efficiency, low-noise, step-up Up to 95% Efficiency DC-DC converter intended for use in battery-powered Up to 1.5A Output wireless applications. It uses a synchronous-rectified Fixed 5V or Adjustable Step-Up Output pulse-width-modulation (PWM) boost topology to gen- (2.5V to 5.5V) erate a 2.5V to 5.5V output from battery inputs, such as one to three NiCd/NiMH cells or one Li-Ion cell. The 0.7V to 5.5V Input Range device includes a 2A, 75m, N-channel MOSFET Low-Power Mode (300W) switch and a 140m, P-channel synchronous rectifier. Low-Noise, Constant-Frequency Mode (300kHz) With its internal synchronous rectifier, the MAX1703 Synchronizable Switching Frequency delivers up to 5% better efficiency than similar nonsyn- (200kHz to 400kHz) chronous converters. It also features a pulse-frequency- modulation (PFM) low-power mode to improve efficiency 1A Logic-Controlled Shutdown at light loads, and a 1A shutdown mode. Power-Good Comparator The MAX1703 comes in a 16-pin narrow SO package Uncommitted Gain Block and includes an uncommitted comparator that generates a power-good or low-battery-warning output. It also Ordering Information contains a linear gain block that can be used to build a linear regulator. PART TEMP. RANGE PIN-PACKAGE For lower-power outputs and a smaller package, refer MAX1703ESE -40C to +85C 16 Narrow SO to the MAX1700/MAX1701. For dual outputs (step-up plus linear regulator), refer to the MAX1705/MAX1706. For an on-board analog-to-digital converter, refer to the Applications MAX848/MAX849. Digital Cordless Phones Personal Communicators The MAX1703 evaluation kit is available to speed designs. PCS Phones Palmtop Computers Wireless Handsets Hand-Held Instruments Two-Way Pagers Typical Operating Circuit Pin Configuration INPUT 0.7V TO 5.5V TOP VIEW OUTPUT 5V OR ADJ MAX1703 UP TO 1.5A REF 1 16 ON LXP, LXN OFF ON ON FB 2 15 POUT POUT PWM POKIN 3 14 LXP CLK/ OR SYNC SEL 4 MAX1703 OUT 13 POUT PFM OUT GND 5 12 PGND POWER-GOOD POKIN AIN 6 11 LXN INPUT POWER-GOOD POK AIN GAIN-BLOCK INPUT OUTPUT AO 7 10 PGND GAIN-BLOCK REF AO POK 8 9 CLK/SEL OUTPUT FB GND PGND Narrow SO Maxim Integrated Products 1 For free samples & the latest literature: 1-Cell to 3-Cell, High-Power (1.5A), Low-Noise, Step-Up DC-DC Converter ABSOLUTE MAXIMUM RATINGS Operating Temperature Range ...........................-40C to +85C OUT, ON, AO, POK to GND .....................................-0.3V to +6V PGND to GND.....................................................................0.3V Junction Temperature......................................................+150C Storage Temperature Range .............................-65C to +160C LXP, LXN to PGND .................................-0.3V to (V + 0.3V) POUT POUT, CLK/SEL, AIN, REF, FB, Lead Temperature (soldering, 10sec) .............................+300C POKIN to GND.......................................-0.3V to (V + 0.3V) OUT Continuous Power Dissipation (T = +70C) A Narrow SO (derate 8.70mW/C above +70C) .............696mW 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 (CLK/SEL = AIN = ON = POKIN = FB = PGND = GND, OUT = POUT, LXP = LXN, V = 5.3V (Note 1), T = 0C to +85C, unless OUT A otherwise noted. Typical values are at T = +25C.) A PARAMETER CONDITIONS MIN TYP MAX UNITS DC-DC CONVERTER Input Supply Range (Note 2) 0.7 5.5 V Minimum Start-Up Voltage I < 1mA, T = +25C (Note 3) 0.9 1.1 V LOAD A Frequency in Start-Up Mode V = 1.5V 40 140 300 kHz OUT Output Voltage V < 0.1V, CLK/SEL = OUT, FB 4.87 5.05 5.20 V (Note 4) 0 I 1.1A, V = 3.7V LX BATT Adjustable output, CLK/SEL = OUT, FB Regulation Voltage 1.21 1.24 1.255 V 0 I 1.1A, V = 2.2V, V = 3.3V LX BATT OUT FB Input Current V = 1.25V 0.1 20 nA FB Output Voltage Adjust Range 2.5 5.5 V Output Voltage Lockout Threshold (Note 5) 2.0 2.15 2.3 V Load Regulation (Note 6) CLK/SEL = OUT, no load to full load -1.6 % Supply Current in Shutdown ON = OUT 0.1 20 A Supply Current in Low-Power Mode CLK/SEL = GND (Note 1) 65 120 A Supply Current in Low-Noise Mode CLK/SEL = OUT (Note 1) 150 300 A DC-DC SWITCHES POUT, LXP Leakage Current V = 0V, V = V = 5.5V 0.1 20 A LXP OUT ON LXN Leakage Current V = V = V = 5.5V 0.1 20 A ON LXN OUT CLK/SEL = GND 0.14 0.25 Switch On-Resistance N-channel Switch On-Resistance CLK/SEL = OUT 0.075 0.13 P-channel 0.13 0.25 CLK/SEL = OUT 2200 2700 3200 mA N-Channel Current Limit CLK/SEL = GND 500 800 1100 mA P-Channel Turn-Off Current CLK/SEL = GND 20 160 260 mA POWER-GOOD COMPARATOR POKIN Trip Level Rising V 1.225 1.250 1.275 V POKIN POKIN Input Current V = 0.7V -20 20 nA POKIN I (POK) = 1mA, V = 3.6V or SINK OUT POK Low Voltage 0.03 0.4 V I (POK) = 20A, V = 1V SINK OUT POK High Leakage Current V = V = 5.5V 0.01 1 A OUT POK 2 MAX1703