FEATURES
FM-704A EMI FILTER
40 WATT
EMI INPUT
F
ILTER AND
UPPRESSION
ODULE, 28 VOLT NPUT
• –55°C to +125°C operation
• 16 to 40 VDC input
• Up to 60 dB attenuation
at 500 kHz.
T
RANSIENT
S
• Active transient suppression
• Undervoltage lockout
• Inhibit function
MODEL
M
I
FM-704A
40 Watts
• Compliant to
MIL-STD-461C, CE03
Size (max): 2.910 x 1.125 x 0.400 inches (73.91 x 28.58 x 10.16 mm)
See Section B8, case K1, for dimensions.
Weight:
40 grams maximum
Screening: Standard, ES, or 883 (Class H). See Section C2 for screening
options, see Section A5 for ordering information.
DESCRIPTION
INTERNAL POWER DISSIPATION
Interpoint’s FM-704A™ EMI Filter and Transient Suppression
Module combines EMI filtering and transient protection to handle the
demanding requirements of military, aerospace and industrial appli-
cations. As an EMI filter the FM-704A filter reduces the reflected
ripple current from DC/DC switching converters. As a protection
module, it suppresses input transients on the power bus to protect
the converter and other downstream components.
To keep internal power dissipation to safe operating levels, the input
current should never exceed 2.5 amps at 16 Vin or 1.0 amp at 40
Vin. When the FM-704A filter is used with PWM (Pulse Width
Modulated) converters, I
will vary as Power / V
and 2.5 amps
line
line
maximum at 16 Vin will reduce to approximately 1 amp maximum
at 40 Vin. The maximum value allowed may be less than 1 amp as
determined by line transients and the safe operating area of Figure
9.
MIL-STD NOISE MANAGEMENT
When used in conjunction with Interpoint converters, the FM-704A
EMI filter reduces reflected input ripple current by a minimum of 60
dB at 500 kHz and 55 dB at 1 MHz (see Figures and Electrical
Characteristics table). This attenuation gives the converter/filter
combination performance exceeding MIL-STD-461C’s CE03 test.
Although the FM-704A filter effectively attenuates the ripple gener-
ated by switching converters, it will not suppress RF applied to its
input terminals.
Figure 9 illustrates the maximum allowed internal dissipation for the
FM-704A filter. To calculate watts dissipated, subtract 40 volts from
the transient (VT) to determine the maximum voltage across the
filter and multiply the result by the current (the filter’s output power,
Pout divided by 40).
W = (V - 40) x P /40
T
out
For example, with 20 watts output and a transient of 400 volts:
W = (400 - 40) x 20/40 = 180
The curve of Figure 9 shows that 180 W can be dissipated for up to
4 milliseconds.
TEMPERATURE OPERATION
FM-704A filters are rated to operate from -55°C to +125°C base-
plate temperature. To meet MIL-STD-1275A and MIL-STD-704A
requirements, derate output power linearly from 40 watts at 105°C
to 25 watts at 125°C. See Figure 9.
FEATURES
The inhibit function allows the FM-704A filter to be used as a high-
side switch. When the inhibit terminal (pin 6) is left open or pulled
high, the FM-704A filter is enabled. When the terminal is grounded,
the filter shuts off output power.
PROTECTION
To provide protection for itself and converters, the FM-704A filter
blocks transients as required by the following standards:
A soft start function helps reduce inrush current and start-up over-
shoot when the filter is initially powered or when it is released from
the inhibit mode.
MIL-STD-704A
MIL-STD-461B&C
MIL-STD-1275
Panavia SP-P-90001
British Standard BS3G100
Civil Aircraft D0160B
An undervoltage lockout feature shuts off output power when input
voltage falls below a specified level. Refer to Figure 8 for more infor-
mation.
Refer to the Electrical Characteristics table on the following page for
more information.
Reverse polarity spikes of up to 100 V will not damage the filter,
however the spikes will not be blocked by the filter.
LAYOUT REQUIREMENTS
The case of the filter must be connected to the case of the converter
through a low impedance connection to minimize EMI.
B3-3
5秒后页面跳转
LM317T数据手册解读：产品特性、应用、封装与引脚详解
一文带你了解?DB3二极管好坏判断、参数信息、替代推荐
LM358DR数据手册：引脚说明、电气参数及替换型号推荐
OP07CP数据手册解读：引脚信息、电子参数
微信公众号
抖音公众号
浙公网安备 33010502006866号 浙ICP备10014259号-119
营业执照ICP证
技术参数
数据手册
如果您发现信息不准确，
