OVERVIEW AND GENERAL OPERATION

The chip is a fixed frequency Pulse Width Modulator based on the industry standard UC1843x Series with significant enhancements in performance and functionality. The chip operates in either the voltage or current mode and can support a wide variety of converter topologies.

Radiation hardened by design techniques ensure the chip’s outstanding radiation tolerance (>1MRads) while reducing operating current by more than an order of magnitude over comparable parts.

The PWM5031 provides an under voltage lockout feature with hysteresis that also provides an output to indicate Power is OK. An input called Sleep is used to power down the entire chip, the Enable input is used to shut down the Oscillator / Output Drives, and the Soft input drives the Output to zero. There is also a signal input called ENAUX that is used to disable the output to the auxiliary op-amp.

The dual output drivers are designed using a Totem Pole output capable of sinking and sourcing 50mA constant current and peak currents up to 1 Amp to support a large variety of Power MOSFETs.

FEATURES

❑ Radiation Hardness:

   - Total Dose 1MRad(Si)

   - Single Event Upset (SEU) 100MeV-cm2/mg

❑ CMOS Low Power Design

❑ Sleep & Enable Control Lines

❑ Optimized for Applications: Buck, Boost, Flyback, Forward and Center Tapped Push-Pull Converters

❑ Supports Current Mode or Voltage Mode Operations

❑ Selectable 50% / 100% Duty Cycle

❑ Under-Voltage Lockout with Hysteresis

❑ Dual ±1Amp Peak Totem Pole Outputs

❑ 1 MHz Maximum – User Selectable

❑ Low RO Error Amp

❑ Auxiliary Op Amp with Shut Down Pin

❑ Power OK Indicator

❑ Designed for Commercial, Industrial and Aerospace Applications

❑ Ceramic 24-Gull lead, Hermetic Package, .6L x .3W x .13H

   - Contact Factory for Die Availability

❑ DSCC SMD Pending