MAX748A

Up to 500mA Load Currents
Guaranteed 159kHz to 219.5kHz Current-Mode PWM
85% to 90% Efficiencies
1.7mA Quiescent Current (MAX748A) 1.4mA Quiescent Current (MAX763A)
0.2A Shutdown Supply Current
22H Preselected Inductor Value; No Component Design Required
Overcurrent, Soft-Start, and Undervoltage Lockout Protection
Cycle-by-Cycle Current Limiting
8-Pin DIP/SO Packages (MAX763A)

5V-to-3.3V Converters Cellular Phones
Portable Instruments Hand-Held Computers
Computer Peripherals

Pin Voltages:
V+ (MAX748A)......................................................+17V, -0.3V
V+ (MAX763A)......................................................+12V, -0.3V
LX (MAX748A) ..................................(V+ - 21V) to (V+ + 0.3V)
LX (MAX763A) ..................................(V+ - 12V) to (V+ + 0.3V)
OUT................................................................................±25V
SS, CC, SHDN ..........................................-0.3V to (V+ + 0.3V)
Peak Switch Current (ILX) ...............................................2.0A
Reference Current (IREF) ..............................................2.5mA
Continuous Power Dissipation (TA = +70°C)
8-Pin Plastic DIP (derate 6.90mW/°C above +70°C)..552mW
8-Pin SO (derate 5.88mW/°C above +70°C) .............471mW
16-Pin Wide SO (derate 9.52mW/°C above +70°C)...762mW
8-Pin CERDIP (derate 8.00mW/°C above +70°C) ......640mW
Operating Temperature Ranges:
MAX7__AC__ ....................................................0°C to +70°C
MAX7__AE__ .................................................-40°C to +85°C
MAX7__AMJA__ ............................................-55°C to +125°C
Junction Temperatures:
MAX7__AC/E ................................................................+150°C
MAX7__AM....................................................................+175°C
Storage Temperature Range .......................-65°C to +160°C
Lead Temperature (soldering, 10sec) ..........................+300°C

The MAX748A/MAX763A are 3.3V-output CMOS, stepdown switching regulators. The MAX748A accepts inputs from 3.3V to 16V and delivers up to 500mA. The MAX763A accepts inputs between 3.3V and 11V and delivers up to 500mA. Typical efficiencies are 85% to 90%. Quiescent supply current is 1.4mA (MAX763A), and only 0.2A in shutdown.

Pulse-width-modulation (PWM) current-mode control of MAX748A provides precise output regulation and excellent transient responses. Output voltage accuracy is guaranteed to be ±5% over line, load, and temperature variations. Fixed-frequency switching allows easy filtering of output ripple and noise, as well as the use of small external components. A 22H inductor works in most applications, so no magnetics design is necessary.

The MAX748A/MAX763A also feature cycle-by-cycle current limiting, overcurrent limiting, undervoltage lockout, and programmable soft-start protection. The MAX748A is available in 8-pin DIP and 16-pin wide SO packages; the MAX763A comes in 8-pin DIP and SO packages.