MAXIM MAX1902EAI 500kHz Multi-Output, Low-Noise Power-Supply Controllers

Description:

The MAX1901/MAX1902/MAX1904 are buck-topology, step-down, switch-mode, power-supply controllers that generate logic-supply voltages in battery-powered systems.These high-performance, dual/triple-output devices include on-board power-up sequencing, power-good signaling with delay, digital soft-start, secondary winding
control, low dropout circuitry, internal frequency-compensation networks, and automatic bootstrapping.
Up to 97% efficiency is achieved through synchronous rectification and Maxim's proprietary Idle Mode control scheme. Efficiency is greater than 80% over a 1000:1
load-current range, which extends battery life in system suspend or standby mode. Excellent dynamic response corrects output load transients within five clock cycles.
Strong 1A on-board gate drivers ensure fast external Nchannel MOSFET switching.
These devices feature a logic-controlled and synchronizable, fixed-frequency, pulse-width modulation (PWM) operating mode. This reduces noise and RF interference
in sensitive mobile communications and pen-entry applications. Asserting the SKIP pin enables fixed-frequency mode, for lowest noise under all load conditions.
The MAX1901/MAX1902/MAX1904 include two PWM regulators, adjustable from 2.5V to 5.5V with fixed 5.0V and 3.3V modes. All these devices include secondary feedback
regulation, and the MAX1902 contains a 12V/120mA linear regulator. The MAX1901/MAX1904 include a secondary feedback input (SECFB), plus a control pin
(STEER) that selects which PWM (3.3V or 5V) receives the secondary feedback signal. SECFB provides a method for adjusting the secondary winding voltage regulation
point with an external resistor divider, and is intended to aid in creating auxiliary voltages other than fixed 12V.
The MAX1901/MAX1902 contain internal output overvoltage and undervoltage protection features.

Features:

• 97% Efficiency
• 4.2V to 30V Input Range
• 2.5V to 5.5V Dual Adjustable Outputs
• Selectable 3.3V and 5V Fixed or AdjustableOutputs (Dual Mode)
• 12V Linear Regulator
• Adjustable Secondary Feedback (MAX1901/MAX1904)
• 5V/50mA Linear Regulator Output
• Precision 2.5V Reference Output
• Programmable Power-Up Sequencing
• Power-Good (RESET) Output
• Output Overvoltage Protection (MAX1901/MAX1902)
• Output Undervoltage Shutdown (MAX1901/MAX1902)
• 333kHz/500kHz Low-Noise, Fixed-Frequency Operation
• Low-Dropout, 98% Duty-Factor Operation
• 2.5mW Typical Quiescent Power (12V input, both SMPSs on)
• 4μA Typical Shutdown Current

Applications:

• Notebook and Subnotebook Computers
• PDAs and Mobile Communicators
• Desktop CPU Local DC-DC Converters

Package included:

• 1 x MAXIM MAX1902EAI 500kHz Multi-Output, Low-Noise Power-Supply Controllers