部品番号 : MAX1742
詳細 : 1A/2.7A / 1MHz / Step-Down Regulators with Synchronous Rectification and Internal Switches
メーカー : Maxim Integrated
ピン配置図 :
部品情報 :
General Description
The MAX1742/MAX1842 constant-off-time, pulse-width modulated (PWM) step-down DC-DC converters are ideal for use in 5V and 3.3V to low-voltage conversion neces
sary in notebook and subnotebook computers. These devices feature internal synchronous rectification for high efficiency and reduced component count. They require no external Schottky diode. The internal 90mΩ PMOS power switch and 70mΩNMOS synchronous-rectifier switch easily deliver continuous load currents up to 1A. The MAX1742/MAX1842 produce a preset 2.5V, 1.8V, or 1.5V output voltage or an adjustable output from 1.1V to
VIN. They achieve efficiencies as high as 95%. The MAX1742/MAX1842 use a unique current-mode, constant-off-time, PWM control scheme, which includes Idle Mode™ to maintain high efficiency during light-load operation. The programmable constant-off-time architecture sets switching frequencies up to 1MHz, allowing the user to optimize performance trade-offs between efficiency, output switching noise, component size, and
cost. Both devices are designed for continuous output currents up to 1A. The MAX1742 uses a peak current limit of 1.3A (min) and is suitable for applications requiring small external component size and high efficiency.
The MAX1842 has a higher current limit of 3.1A (min) and is intended for applications requiring an occasional burst of output current up to 2.7A. Both devices also fea
ture an adjustable soft-start to limit surge currents during startup, a 100% duty cycle mode for low-dropout operation, and a low-power shutdown mode that disconnects
the input from the output and reduces supply current below 1µA. The MAX1742/MAX1842 are available in 16-pin QSOP packages.
Features
♦±1% Output Accuracy
♦95% Efficiency
♦Internal PMOS and NMOS Switches
90mΩ On-Resistance at VIN = 4.5V
110mΩ On-Resistance at VIN = 3V
♦Output Voltage
2.5V, 1.8V, or 1.5V Pin Selectable
1.1V to VIN Adjustable
♦3V to 5.5V Input Voltage Range
♦600μA (max) Operating Supply Current
♦<1μA Shutdown Supply Current
♦Programmable Constant-Off-Time Operation
♦1MHz (max) Switching Frequency
♦Idle-Mode Operation at Light Loads
♦Thermal Shutdown
♦Adjustable Soft-Start Inrush Current Limiting
♦100% Duty Cycle During Low-Dropout Operation
♦Output Short-Circuit Protection
♦16-Pin QSOP Package
データシート PDF ダウンロード
ファイル内の他のデータシート :
MAX1742,MAX1742EEE,MAX1742EEE+,MAX1842,MAX1842EEE
