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HIGH TEMPERATURE

HYBRID DC-DC CONVERTER

HTB28XXS

Description

n Case Operating Temperatures: -35°C to +185°C

n Life > 1200 hours @ +185°C

n Up to 5W Output Power

n Wide Input Voltage Range: 17 to 34 Volts

n Single Outputs: 3.3V, 5V, 12V and15V

n Minimum Efficiency 69%

n Low Inhibit Current (less than 3.5mA)

n External Inhibit / Enable

n Short Circuit and Overload Protection

n Under-Voltage Lockout Protection

n Industry Standard Pin-out

n Compact Flanged Package: 1.0”W x 0.41”H x 2.82”L

n Parallel Seam Welded Steel Package

Features

185°C, 5W, 28V Input, Single Output

The HTB28XXS Series is a hybrid, hermetically sealed, single

output 5W DC-DC converter designed to operate in high

temperature up to 185°C and shock and vibration environments

such as those encountered in oil exploration applications.

Features include small size, 1" width and low weight. All internal

components are specifically selected to meet the intended

operating environment. Documentation, including electrical

stress and thermal analysis, is available to customers.

07/07/15

HTB

The HTB28XXS Series of DC-DC converters use flyback

topology, operating at a nominal frequency of 550 kHz. High

input to output galvanic isolation is achieved through the use

of transformers in the power and feedback paths. The

advanced feedback design provides fast loop response for

superior line and load transient characteristics and offers

greater reliability than converters incorporating optical feedback

circuits.

These converters are designed to meet full performance over

a 17 to 34 volts input range and provide output power of up to

5 watts. An inhibit pin allows to shut the converter down or

enable it.

Output current is limited under any load fault condition to

approximately 180% of rated value. An overload condition

causes the converter output to limit current. The converter will

remain in current limit mode until the load current is reduced

below the overcurrent limit, at which time it will resume normal

operation. This protects the converter as well as load from

both overload and short circuit conditions.

The converters are enclosed in a 1.0"W x 0.41"H x 2.82"L

flanged package excluding mounting tabs and I/O pins and

weigh less than 44 grams. The cold rolled steel (CRS) package

utilizes rugged ceramic feed-thru copper core pins and is

sealed with parallel seam welding.

Full environmental screening includes temperature cycling,

constant acceleration, fine and gross leak testing and burn-in

as per Device Screening table. Variations in electrical

specifications and screening to meet custom requirements

may be accommodated.

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Applications

n Down Hole Exploration Tools

PD-97825