Manufacture Diodes, IGBTs, LED Driver, Small Signal & Analog, RF Power, SCR, WLAN Power Amplifier, Backlight Inverter, CCFL Inverter, Power Modules, RF Transistors, Power Over Ethernet, PoE, PoE IC


keyword search:			part number search:

UM9989 (#77533)

Specialty PIN Diodes
Division	Lowell	Datasheet	UM9989_Datasheet.pdf
Mil-Spec	(none)	Spice Data	(none)
Shipping	(none)	Qual Data	Contact Microsemi
ROHS By Design
Description
The UM9989 diode series was designed to protect MRI receivers from high RF energy fields including long RF pulses and RF spike pulses present in most MRI machines. The UM9989 acts as a passive protector (limiter) for the MRI receiver. No forward bias voltage is required to turn on the diode. It is self-biased by the RF transmitter pulse power. A switch driver is not needed for this receiver protection application. Receiver protector diodes appear directly across the input port of the receiver. They are connected in anti-parallel pairs to limit the RF carrier excursion in both polarities. They must, therefore, exhibit extremely low insertion loss, both in the �on� state (high power present) and the �off� state (receiver power present) so as not to decrease the receiver�s sensitivity. The UM9989 diodes are available in two package configurations for flexibility in design.

Maximum Electrical Rating	Symbol	Max	Unit
Reverse Voltage	V_R	75	V
Thermal Resistance, Junction to Case	R_qJC	100	�C/Watt

Environmental Rating	Symbol	Min	Max	Unit
Operating Temperature	T_OP	-65	150	�C
Storage Temperature	T_STG	-65	150	�C

Electrical Rating	Symbol	Min	Typ	Max	Unit
Reverse Breakdown Voltage
(I_R=10 �A)	V_BR	75			V
Total Capacitance
(V_R=0 V)	Ct		1.2	5	pF
Series Resistance
(I_F=100 mA)	R_S		0.3	0.5	Ohms
Parallel Resistance
(V_R=0 V)	R_P	25	40		Kohm

Package

SM(STD)

Privacy Policy | Site Map | Terms & Conditions

Avionics | Backlight Inverters | L-Band Radar | LED Driver | LDMOS & VDMOS | MOSFETs, IGBTs, & Diodes | Pin Diodes | Power Modules
RF Power & Bipolar Transistors | S-Band Radar | SCR | Thyristors | Varacter Diode | WLAN Power Amplifier | Zener Diode | Power Over Ethernet | IEEE802.3af | PoE ICs

Copyright © 2010 Microsemi Corporation. All rights reserved. The Endwave logo is a registered trademark of Endwave Corporation.