MTO812T Datasheet, PDF (1/6 Pages) Interpoint Corporation Company – –55°C to +85° C operation 50 V for 50 ms transient protection

DC/DC Converters
28 Volt Input
NOT RECOMMENDED FOR NEW DESIGNS
mto Series
15 Watt
Features
• –55°C to +85° C operation
• 16 to 36 VDC input
• 50 V for 50 ms transient protection
• Fully isolated
• Fixed frequency switching
• Inhibit function
• Indefinite short circuit protection
• Up to 79% efficiency
models
VDC Output
triple
+5 & ±12
+5 & ±15
Size (max.): Non-flanged, case F4, 1.950 x 1.350 x 0.505 inches (49.53 x 34.29 x 12.83 mm)
Flanged, case J5, 2.720 x 1.350 x 0.505 inches (69.09 x 34.29 x 12.83 mm)
See cases F4 and J5 for dimensions.
Weight: 53 grams typical
Screening: Standard or ES. See screening table for more information.
Description
Interpoint’s MTO Series™ of DC/DC converters delivers 15 watts of output
power with three output voltages and a choice of two input voltage ranges.
The MTO Series converters are packaged in hermetically sealed metal
cases and operate at full load over a case temperature range of -55°C to
+85°C (measured at the base plate of the converter).
Features
An inhibit terminal, pin 8, provides shut-down and start-up control. Applying
a logic low (<0.8 V) will disable the output of the converter reducing input
current to 8 mA, typical. Leaving the terminal unconnected or connecting it
to Vin will enable the converter. The inhibit pin has an open circuit voltage
of approximately 10 volts.
Converter Design
The push-pull forward topology coupled with pulse-width modulation
minimizes output noise and maintains good regulation. Nominal switching
Soft-start provides a controlled 20 milliseconds turn-on to minimize inrush
current and reduce overshoot at initial start-up or when inhibit is released.
frequency is 250 kHz. Although an internal input filter reduces input ripple
current, for applications requiring conformance to MIL-STD-461C, CE03,
use the MTO in conjunction with Interpoint’s FM-461 EMI filter.
Internal current limiting circuitry protects all three outputs against short
circuits. When output power exceeds approximately 125% of maximum
output power, the output currents are limited. In addition, separate current
Operating at maximum ratings may require removing self-generated heat. ^{limiting circuitry protects each output individually.}
To increase heat dissipation, heat conducting material can be used in
contact with the converter’s base plate. Interpoint’s Thermal Mounting Pad
(TMP), model TMP-002, is designed for use with the MTO converter.
Packaging
MTO converters are packaged in hermetically sealed metal cases. The cases
Positive 1
Input
Pre-
Regulator
2 _{+5 Vout}
are constructed of cold-
rolled steel with a fused tin
finish. MTO converters can
be purchased in a flanged
or non-flanged case. The
Pulse
Width
Modulator
Error
flanged option provides
Amp
3 _Output
Common
increased heat dissipation
and also provides greater
stability when mechanically
secured.
Short Circuit Amp
Pass Transistor
5 _Positive
Input 10
Common
Inhibit ⁸
Linear
Regulator
Auxiliary
Output
Case Ground ⁷
Linear
Regulator
Pass Transistor
Figure 1: Simplified Schematic
4 _Negative
Auxiliary
Output
Crane Aerospace & Electronics
Electronics Group (Interpoint Brand)
PO Box 97005 • Redmond WA 98073-9705
425.882.3100 • [e-mail]
www.interpoint.com
Page ­1­­ of 6
MTO Rev C 20100212