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SCD5031 Rev B

FEATURES

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Radiation Hardness:

- Total Dose 1MRad(Si)

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CMOS Low Power Design

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Sleep & Enable Control Lines

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

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Supports Current Mode or Voltage Mode Operations

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Selectable 50% / 100% Duty Cycle

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Under-Voltage Lockout with Hysteresis

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Dual ±1Amp Peak Totem Pole Outputs

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1 MHz Maximum – User Selectable

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Low RO Error Amp

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Auxiliary Op Amp with Shut Down Pin

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Power OK Indicator

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Designed for Commercial, Industrial and Aerospace Applications

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

- Contact Factory for Die Availability

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DSCC SMD Pending

NOTE: Aeroflex Plainview does not currently have a DSCC Certified Radiation Hardened Assurance Program

Developed in Partnership with JHU/APL and the Technology Application Group for the Mars Technology

Program; Part of NASA’s Mars Exploration Program

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.

Additional features that boost the appeal and utility of the part are:

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Dual break-before-make Totem Pole output stage is employed that virtually eliminates cross conduction and

current shoot through

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Logic level input that allows the user to select either 50% or 100% maximum duty cycle operation

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Improved oscillator stage that vastly increases waveform linearity and reduces output voltage error

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Uncommitted on-board op-amp which can be used for signal conditioning, pulse feedback, or any other user

defined purpose

PWM5031 RadHard High Speed PWM Controller

Standard Products

www.aeroflex.com/Power

August 2, 2005