MCH2805S_13 Datasheet, PDF (1/13 Pages) Interpoint Corporation Company – MCH/MGH Single and Dual DC-DC Converters 28 Volt input – 1.5 Watt

Crane Aerospace & Electronics Power Solutions
MCH/MGH Single and Dual DC-DC Converters
28 Volt input – 1.5 Watt
Features
Small footprint, 0.79 in² (5.1 cm²) - MCH
Surface mount package - MGH
• Operating temperature -55°C to +125°C
• Input voltage 12 to 50 VDC
• Transient protection 80 V for up to 120 ms
-- 70 V for 15 V single and dual models
• Fully isolated, magnetic feedback
• Fixed frequency switching
• Inhibit function
• Short circuit protection
• Undervoltage lockout
• Up to 79% efficiency
models
VDC Output
SINGLE DUAL
5
±5
12
±12
15
±15
DESCRIPTION
The Interpoint™ MCHSeries™ and MGH Series™ of dc-dc
converters deliver 1.5 watts of output power while saving
significant board real estate. The wide input voltage range of 12
to 50 VDC accepts the varying voltages of military, aerospace, or
space bus power and tightly regulates output voltages to protect
downstream components. Transient protection of 80 volts for up
to 120 milliseconds exceeds the requirements of MIL-STD-704A
for the 5 and 12 volt single models and the 12 volt dual model.
The 15 volt single and dual converters will withstand transients of
up to 70 volts for up to 120 milliseconds.
The converters are offered with standard screening, “ES”
screening, or fully compliant to “883” MIL-PRF-38534 Class H
screening. See “Table 11: Element Evaluation” on page 12 and
“Table 12: Environmental Screening” on page 13. Standard
microcircuit drawings (SMD) are available. See “Table 5:
MCH SMD Numbers” on page 4 and “Table 6: MGH SMD
Numbers” on page 4.
Converter Design
MCH Series and MGH Series of dc-dc converters incorporate a
continuous flyback topology with a constant switching ­frequency
of approximately 370 kHz.Current-mode pulse width modulation
(PWM) provides output voltage regulation. Output error voltage
is magnetically fed back to the input side of the PWM to regulate
output voltage. Regulation is also affected by the load; refer
to the Electrical Characteristics Table 9 on page 6 and
Table 10 on page 7.
Dual models regulate the negative output with magnetic coupling
to the positive output. Up to 80% of the total load may be on
one output providing that the other output carries a minimum of
20% of the total load. The dual models can be used at double
the output voltage by connecting the load between positive and
negative outputs, leaving the common unconnected.
(ex: MCH2805D can be used as a 10 VDC output.)
Inhibit Function
MCH and MGH converters provide an inhibit terminal that can be
used to disable internal switching, resulting in no output voltage
and an input current as low as 2.3 mA. The converter is inhibited
when the inhibit pin is pulled below 0.8 V and enabled when its
inhibit pin is left floating. An external inhibit interface should be
capable of pulling the converter’s inhibit pin below 0.8 V while
sinking the maximum inhibit current and also allowing the inhibit
pin to float high to enable the converter. A voltage should not be
applied to the inhibit pin. The open circuit voltage present on the
inhibit pin is 7 to 12 V.
Protection Features
Undervoltage lockout prevents the converters from operating
below approximately 8 VDC input voltage to keep system
current levels smooth, especially during initialization or re-start
operations. All models include a soft-start function to prevent
large current draw and minimize overshoot. The converters also
provide short circuit protection by restricting the current.
MIL-STD-461
Use the Interpoint FMSA-461 (down-leaded) or FMGA-461
(surface mount, side-leaded) EMI filters to pass the CE03
requirements of MIL-STD-461C.
Crane Aerospace & Electronics
Power Solutions – Interpoint Products
10301 Willows Rd. NE, Redmond, WA 98052
+1.425.882.3100 • [e-mail]
www.craneae.com/interpoint
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MCH_MGH Rev AB - 2013.05.31