Document
19-1698; Rev 1; 2/01
1.5A, Low-Noise, 1MHz, Step-Up DC-DC Converter
General Description
The MAX1763 is a high-efficiency, low-noise, step-up DC-DC converter intended for use in battery-powered wireless applications. This device maintains exceptionally low quiescent supply current (110µA) despite its high 1MHz operating frequency. Small external components and a tiny package make this device an excellent choice for small hand-held applications that require the longest possible battery life. The MAX1763 uses a synchronous-rectified pulsewidth-modulation (PWM) boost topology to generate 2.5V to 5.5V outputs from a wide range of input sources, such as one to three alkaline or NiCd/NiMH cells or a single Lithium-ion (Li+) cell. Maxim's proprietary Idle Mode™ circuitry significantly improves efficiency at light load currents while smoothly transitioning to fixed-frequency PWM operation at higher load currents to maintain excellent full-load efficiency. Lownoise, forced-PWM mode is available for applications that require constant-frequency operation at all load currents. The MAX1763 may also be synchronized to an external clock to protect sensitive frequency bands in communications equipment. The MAX1763 includes an on-chip linear gain block that can be used to build a high-power external linear regulator or as a low-battery comparator. Soft-start and current limit functions permit optimization of efficiency, external component size, and output voltage ripple. The MAX1763 is available in a space-saving 16-pin QSOP package or a high-power (1.5W) 16-pin TSSOPEP package. o Up to 94% Efficiency o +0.7V to +5.5V Input Voltage Range o 1.1V Guaranteed Startup Input Voltage o Up to 1.5A Output o Fixed 3.3V Output or Adjustable (2.5V to 5.5V) o 1MHz PWM Synchronous-Rectified Topology o 1µA Logic-Controlled Shutdown o Analog Gain Block for Linear-Regulator or LowBattery Comparator o Adjustable Current Limit and Soft-Start o 1.5W TSSOP Package Available
Features
MAX1763
________________________Applications
Digital Cordless Phones PCS Phones Wireless Handsets Hand-Held Instruments Palmtop Computers Personal Communicators
Ordering Information
PART MAX1763EEE MAX1763EUE TEMP RANGE -40°C to +85°C -40°C to +85°C PIN-PACKAGE 16 QSOP 16 TSSOP-EP*
Typical Operating Circuit
IN 0.7V TO 5.5V 1.5µH OUT 3.3V AT 1.5A
*EP = Exposed pad Idle Mode is a trademark of Maxim Integrated Products.
Pin Configuration
TOP VIEW
ONA 1 ISET 2
OFF ON PWM OR NORMAL LBI OR GAIN BLOCK INPUT MAX1763 ON OFF ONB ONA CLK/SEL AIN ISET REF FB GND AO PGND LBO OR GAIN BLOCK OUTPUT OUT
LX POUT
16 ONB 15 POUT 14 LX
REF 3 GND 4 FB 5 OUT 6 AIN 7 AO 8
MAX1763
13 POUT 12 PGND 11 LX 10 PGND 9 CLK/SEL
QSOP TSSOP-EP
________________________________________________________________ Maxim Integrated Products
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For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1.5A, Low-Noise, 1MHz, Step-Up DC-DC Conv.