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MAX786, MAX786R, MAX786S

Dual-Output Power Supply Controller for Notebook Computers

Dual-Output 3.3V and 5V Notebook Power Supply Provide Up to 50W with >90% Efficiency

Product Details

The MAX786 is a system-engineered power-supply controller for notebook computers or similar battery-powered equipment. It provides two high-performance step-down (buck) pulse-width modulators (PWMs) for +3.3V and +5V. Other features include dual, low-dropout, micropower linear regulators for CMOS/RTC back-up, and two precision low-battery-detection comparators.

High efficiency (95% at 2A; greater than 80% at loads from 5mA to 3A) is achieved through synchronous rectification and PWM operation at heavy loads, and Idle Mode™ operation at light loads. The MAX786 uses physically small components, thanks to high operating frequencies (300kHz/200kHz) and a new current-mode PWM architecture that allows for output filter capacitors as small as 30µF per ampere of load. Line- and load-transient responses are terrific, with a high 60kHz unity-gain crossover frequency allowing output transients to be corrected within four or five clock cycles. Low system cost is achieved through a high level of integration and the use of low-cost, external N-channel MOSFETs.

Other features include low-noise, fixed-frequency PWM operation at moderate to heavy loads, and a synchronizable oscillator for noise-sensitive applications such as electromagnetic pen-based systems and communicating computers. The MAX786 is a monolithic, BiCMOS IC available in fine-pitch, surface-mount SSOP packages.

Key Features

  • Dual PWM Buck Controllers (+3.3V and +5V)
  • Two Precision Comparators or Level Translators
  • 95% Efficiency
  • 420µA Quiescent Current, 70µA in Standby (linear regulators alive)
  • 25µA Shutdown Current (+5V linear alive)
  • 5.5V to 30V Input Range
  • Small SSOP Package
  • Fixed Output Voltages:
    • 3.3V (standard)
    • 3.45V (High-Speed Pentium®)
    • 3.6V (PowerPC®)

Applications/Uses

  • Communication Systems
  • Notebook Computers
  • Pen-Entry Systems
  • Portable Data Terminals
Parametric specs for Step-Down Switching Regulators
VIN (V) (min) 5.5
VIN (V) (max) 30
VOUT1 (V) (min) 3.3
VOUT1 (V) (max) 5
IOUT1 (A) (max) 5
Switch Type External
Preset VOUT (V) 5
Output Adjust. Method Preset
Resistor
Synchronous Switching? Yes
# DC-DC Outputs 2
Switching Frequency (kHz) 300
Package/Pins SSOP/28
Budgetary
Price (See Notes)
$5.84 @1k
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Simplified Block Diagram

MAX786, MAX786R, MAX786S: Typical Application Circuit MAX786, MAX786R, MAX786S: Typical Application Circuit Zoom icon

Technical Docs

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Parameters

Parametric specs for Step-Down Switching Regulators
VIN (V) (min) 5.5
VIN (V) (max) 30
VOUT1 (V) (min) 3.3
VOUT1 (V) (max) 5
IOUT1 (A) (max) 5
Switch Type External
Preset VOUT (V) 5
Output Adjust. Method Preset
Resistor
Synchronous Switching? Yes
# DC-DC Outputs 2
Switching Frequency (kHz) 300
Package/Pins SSOP/28
Budgetary
Price (See Notes)
$5.84 @1k

Key Features

  • Dual PWM Buck Controllers (+3.3V and +5V)
  • Two Precision Comparators or Level Translators
  • 95% Efficiency
  • 420µA Quiescent Current, 70µA in Standby (linear regulators alive)
  • 25µA Shutdown Current (+5V linear alive)
  • 5.5V to 30V Input Range
  • Small SSOP Package
  • Fixed Output Voltages:
    • 3.3V (standard)
    • 3.45V (High-Speed Pentium®)
    • 3.6V (PowerPC®)

Applications/Uses

  • Communication Systems
  • Notebook Computers
  • Pen-Entry Systems
  • Portable Data Terminals

Description

The MAX786 is a system-engineered power-supply controller for notebook computers or similar battery-powered equipment. It provides two high-performance step-down (buck) pulse-width modulators (PWMs) for +3.3V and +5V. Other features include dual, low-dropout, micropower linear regulators for CMOS/RTC back-up, and two precision low-battery-detection comparators.

High efficiency (95% at 2A; greater than 80% at loads from 5mA to 3A) is achieved through synchronous rectification and PWM operation at heavy loads, and Idle Mode™ operation at light loads. The MAX786 uses physically small components, thanks to high operating frequencies (300kHz/200kHz) and a new current-mode PWM architecture that allows for output filter capacitors as small as 30µF per ampere of load. Line- and load-transient responses are terrific, with a high 60kHz unity-gain crossover frequency allowing output transients to be corrected within four or five clock cycles. Low system cost is achieved through a high level of integration and the use of low-cost, external N-channel MOSFETs.

Other features include low-noise, fixed-frequency PWM operation at moderate to heavy loads, and a synchronizable oscillator for noise-sensitive applications such as electromagnetic pen-based systems and communicating computers. The MAX786 is a monolithic, BiCMOS IC available in fine-pitch, surface-mount SSOP packages.

Simplified Block Diagram

MAX786, MAX786R, MAX786S: Typical Application Circuit MAX786, MAX786R, MAX786S: Typical Application Circuit Zoom icon

Technical Docs

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal