Top

1 Cell to 2 Cell, Low-Noise, High-Efficiency, Step-Up DC-DC Converter

Efficient 1-Cell Step-Up Converter for Pagers

Product Details

Key Features

Parametric specs for Step-Up Switching Regulators
VIN (V) (min) 0.7
VIN (V) (max) 5.5
VOUT1 (V) (min) 2
VOUT1 (V) (max) 5.5
IOUT1 (A) (max) 0.09
Switch Type Internal
Preset VOUT (V) 3
Output Adjust. Method Preset
Resistor
Power Good Signal Yes
Synchronous Switching? Yes
IQ (mA) (typ) 0.037
Shutdown Mode Supply Current (µA) (typ) 0.1
Shutdown Mode Supply Current (µA) (max) 1
# DC-DC Outputs 1
Package/Pins UMAX/8
Budgetary
Price (See Notes)
2.03
View Less

Simplified Block Diagram

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 .

Parameters

Parametric specs for Step-Up Switching Regulators
VIN (V) (min) 0.7
VIN (V) (max) 5.5
VOUT1 (V) (min) 2
VOUT1 (V) (max) 5.5
IOUT1 (A) (max) 0.09
Switch Type Internal
Preset VOUT (V) 3
Output Adjust. Method Preset
Resistor
Power Good Signal Yes
Synchronous Switching? Yes
IQ (mA) (typ) 0.037
Shutdown Mode Supply Current (µA) (typ) 0.1
Shutdown Mode Supply Current (µA) (max) 1
# DC-DC Outputs 1
Package/Pins UMAX/8
Budgetary
Price (See Notes)
2.03

Key Features

  • 0.87V Guaranteed Start-Up
  • Up to 90% Efficiency
  • Built-In Synchronous Rectifier (no external diode)
  • Ultra-Small µMAX Package, 1.1mm High
  • 37µA Quiescent Current (85µA from 1.5V battery)
  • 2µA Logic-Controlled Shutdown
  • Power-Fail Detector
  • Dual Mode™ Output: Fixed 3.3V
  • Dual Mode Adjustable 2V to 5.5V
  • 45mA Output Current at 3.3V for 1-Cell Input
  • 90mA Output Current at 3.3V for 2-Cell Input
  • Inductor-Damping Switch Suppresses EMI

Applications/Uses

  • Pagers
  • Personal Medical Monitors
  • Pointing Devices
  • Remote Controls
  • Single-Cell Battery-Powered Devices

Description

The MAX1678 is a high-efficiency, low-voltage, synchronous-rectified, step-up DC-DC converter intended for use in devices powered by 1 to 3-cell alkaline, NiMH, or NiCd batteries or a 1-cell lithium battery. It guarantees a 0.87V start-up voltage and features a low 37µA quiescent supply current.

The device includes a 1Ω, N-channel MOSFET power switch, a synchronous rectifier that acts as the catch diode, a reference, pulse-frequency-modulation (PFM) control circuitry, and circuitry to reduce inductor ringing-all in an ultra-small, 1.1mm-high µMAX® package.

The output voltage is preset to 3.3V or can be adjusted from +2V to +5.5V using only two resistors. Efficiencies up to 90% are achieved for loads up to 50mA. The device also features an independent undervoltage comparator (PFI/PFO) and a logic-controlled 2µA shutdown mode.

Simplified Block Diagram

MAX1678: Typical Operating Circuit MAX1678: 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 .