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500mA, Low-Dropout, Ripple-Rejecting LDO in µMAX

0.5A, Low-Dropout, Ripple Filter LDO Fits in 8-Pin µMAX

Product Details

Key Features

Parametric specs for Linear Regulators
VIN (V) (min) 2.5
VIN (V) (max) 5.5
Adj. VOUT (V) (min) 1.25
Adj. VOUT (V) (max) 5
Rated ILOAD (mA) 500
Preset VOUT (V) 4.75
# Regulators 1
VDROPOUT @Rated ILOAD (V) (typ) 0.12
ICC (µA) (max) 250
Output Voltage Noise (µV RMS) (typ) 115
Ref. Bypass No
Low Batt./ Pwr. Fail Out No
POK/Reset Thresh. (V) (nom) Vout-14%
Watchdog No
Reverse Batt. Protect. No
Oper. Temp. (°C) -40 to +85
Package/Pins UMAX/8
Budgetary
Price (See Notes)
1.2
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Simplified Block Diagram

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Parameters

Parametric specs for Linear Regulators
VIN (V) (min) 2.5
VIN (V) (max) 5.5
Adj. VOUT (V) (min) 1.25
Adj. VOUT (V) (max) 5
Rated ILOAD (mA) 500
Preset VOUT (V) 4.75
# Regulators 1
VDROPOUT @Rated ILOAD (V) (typ) 0.12
ICC (µA) (max) 250
Output Voltage Noise (µV RMS) (typ) 115
Ref. Bypass No
Low Batt./ Pwr. Fail Out No
POK/Reset Thresh. (V) (nom) Vout-14%
Watchdog No
Reverse Batt. Protect. No
Oper. Temp. (°C) -40 to +85
Package/Pins UMAX/8
Budgetary
Price (See Notes)
1.2

Key Features

  • Guaranteed 500mA Output Current
  • Low 120mV Dropout at 500mA
  • Up to ±1% Output Voltage Accuracy
    • Preset at 4.75V
    • Adjustable from 1.25V to 5.0V
  • Reset Output with 4.5ms Timeout Period
  • Low 135µA Ground Current
  • 0.1µA Shutdown Current
  • Thermal Overload Protection
  • Output Current Limit
  • Tiny µMAX Package

Applications/Uses

  • Cell Phones/Cordless Phones
  • Docking Stations
  • Notebook Computers
  • Palmtop Computers
  • PDAs
  • USB Hubs
  • Wireless Base Stations

Description

The MAX1857 low-dropout linear regulator operates from a +2.5V to +5.5V supply and delivers a guaranteed 500mA load current with low 120mV dropout. The high-accuracy (±1%) output voltage is preset at an internally trimmed 4.75V or can be adjusted from 1.25V to 5.0V with an external resistive divider.

An internal PMOS pass transistor allows the low 135µA supply current to remain independent of load, making this device ideal for portable battery-operated equipment such as personal digital assistants (PDAs), cellular phones, cordless phones, base stations, and notebook computers.

Other features include an active-low open-drain reset output with a 4.5ms timeout period that indicates when the output is out of regulation, a 0.1µA shutdown mode, short-circuit protection, and thermal shutdown protection. The device is available in a miniature 8-pin µMAX package. For higher power applications, refer to the MAX1792 and MAX1793 data sheets.

Simplified Block Diagram

MAX1857: Typical Operating Circuit MAX1857: Typical Operating 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 .