システムボード 6700

MAXREFDES1004: Boost, Single-Output, -73V to -35V Input, 5V/100mA Output DC-DC Converter Using the MAX668


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Input Type VIN (MIN)
(V)
VIN (MAX)
(V)
IOUT
(A)
Single/Multiple
Output
VOUT
(V)
POUT
(W)
Isolated/Non-Isolated Topology
DC -73 -35 0.1 Single 5 0.5 Non-Isolated BOOST

The MAX668/MAX669 constant-frequency, pulse-width modulating (PWM), current-mode DC-DC controllers are designed for a wide range of DC-DC conversion applications, including step-up, SEPIC, flyback, and isolated-output configurations. Power levels of 20W or more can be controlled with conversion efficiencies of over 90%. The input voltage range of 1.8V to 28V supports a wide range of battery and AC-powered inputs. An advanced BiCMOS design features low operating current (220μA), adjustable operating frequency (100kHz to 500kHz), soft-start, and a SYNC input, allowing the MAX668/MAX669 oscillator to be locked to an external clock.

The MAX669 is optimized for low input voltages with a guaranteed start-up voltage of 1.8V. It requires bootstrapped operation (IC-powered from boosted output) and supports output voltages of up to 28V. The MAX668 operates with inputs as low as 3V and can be connected in either a bootstrapped or non-bootstrapped (IC-powered
from input supply or other source) configuration. When not bootstrapped, it has no restriction on output voltage. Both ICs are available in an extremely compact 10-pin μMAX® package.

Key Features

  • 1.8V Minimum Start-Up Voltage (MAX669)
  • Wide Input Voltage Range (1.8V to 28V)
  • Tiny 10-Pin μMAX Package
  • Current-Mode PWM and Idle Mode Operation
  • Adjustable 100kHz to 500kHz Oscillator or SYNC Input
  • 220μA Quiescent Current
  • Logic-Level Shutdown
  • Soft-Start
MAXREFDES1004 Hardware 拡大表示+


This board is not available for purchase.

Designed, Built, Tested

This reference design describes the hardware shown in Figure 1. It provides a detailed systematic technical guide to design a negative input, positive output boost converter using Maxim’s MAX668 current mode controller. The power supply has been built and tested, details of which follow later in this document.

Design Resources

 
Status:
Package:
Temperature:

MAX668
1.8V~28V入力、PWMステップアップコントローラ、µMAXパッケージ

  • 1.8Vのスタートアップ電圧(MAX669)
  • 広い入力電圧範囲(1.8V~28V)
  • 超小型10ピンµMAXパッケージ

MAX669
1.8V~28V入力、PWMステップアップコントローラ、µMAXパッケージ

  • 1.8Vのスタートアップ電圧(MAX669)
  • 広い入力電圧範囲(1.8V~28V)
  • 超小型10ピンµMAXパッケージ