ON UC3844BD1

升压，升压/降压反激，升压10V ~ 30V

Overview

The UC284xB family of control ICs provides the necessary features to implement off-line or DC to DC fixed frequency current mode control schemes with a minimal external parts count. Internally implemented circuits include a trimmed oscillator for precise DUTY CYCLE CONTROL under voltage lockout featuring start-up current less than 0.5mA, a precision reference trimmed for accuracy at the error amp input, logic to insure latched operation, a PWM comparator which also provides current limit control, and a totem pole output stage designed to source or sink high peak current. The output stage, suitable for driving N-Channel MOSFETs, is low in the off-state.

Differences between members of this family are the under-voltage lockout thresholds and maximum duty cycle ranges. The UC2842B and UC2844B have UVLO thresholds of 16V (on) and 10V (off), ideally suited off-line applications The corresponding thresholds for the UC2843B and UC2845B are 8.5V and 7.9V. The UC2842B and UC2843B can operate to duty cycles approaching 100%. A range of the zero to < 50 % is obtained by the UC2844B and UC2845B by the addition of an internal toggle flip flop which blanks the output off every other clock cycle.

Features

Tube Package
Transistor Driver Outputs
Switching Frequency: Up to 500kHz
Frequency Control
PULSE WIDTH MODULATION
Max Duty Cycle: 50 %
Frequency: 500kHz

Surface Mount Mounting Type

Applications

There are a lot of STMicroelectronics
UC3844BD1 DC to DC converter applications.

• CMM
• Various precision measuring instruments
• Various precision measuring detectors
• Flaw detection equipment
• Balance equipment
• Industrial robots
• Industrial controllers
• Die casting equipment
• Injection molding machinery
• Various CNC machine tools