The MAX1791EUB+ is a high efficiency, step-down controller for notebooks in 10 pin µMAX package. This controller provides high efficiency, excellent transient response and high DC output accuracy needed for stepping down high voltage batteries to generate low voltage CPU core, I/O and chipset RAM supplies in notebook computers and PDAs. The Quick-PWM pulse width modulator is a free-running constant on-time type with input feed-forward. It"s high operating frequency (300KHz) allows small external components to be utilized in PC board area-critical applications such as subnotebook, computers and smart phones. PWM operation occurs at heavy loads and automatic switchover to pulse-skipping operation occurs at lighter loads. The external high-side P-channel and low-side N-channel MOSFETs require no bootstrap components. Device is simple, easy to compensate and do not have noise sensitivity of conventional fixed frequency current-mode PWMs.
● Supply voltage range is 5V to 20V, dual mode fixed output of 3.3V/5V/adj
● Operating temperature range from -40°C to 85°C
● No current sense resistor, accurate current limit, free running on demand PWM
● ±1% total DC error over line and during continuous conduction, Foldback Mode UVLO
● Dual mode fixed output of 3.3V (VVP = 5V to 20V), 5V (VVP = 7V to 20V) and adjustable
● 0.5V to 5.5V output adjust range, PFET/NFET synchronous buck
● Automatic light-load pulse skipping operation
● 5µA shutdown supply current
● 230µA quiescent supply current
● 4.65V at 25mA linear regulator output
