Driver circuit for highpower pin diode switches introduction the skyworks highpower pin diode switch driver circuit is a ttldtl compatible, dc coupled, highspeed pin diode bias controller. I previously published a video that introduced the. The switch driver provides output current surges or spikes on the leading and the trailing edge of the input voltage. The anode is the positive terminal and cathode represent their negative terminals.
Supplemental material on pin diode physics is included in the appendices section of the handbook. The driver circuit that is needed for pin diodes almost precludes the use of this technology on volumelimited applications such as tr modules, where element spacing is less than the width of available diode driver circuits. Pin diode switch circuit for short time high current pulse signal. Connecting the switch driver control circuit to a pin diode such that it can turn diodes on and off by applying a forward or reverse bias is a challenging task. The carrier lifetime of pin diode i use is 10microsecondstyp. The back bias voltage can be selected to be any voltage between 20 v to 50 v. I previously published a video that introduced the topic of how diodes can be used as. What is the frequency range of the pin diode as an rf switch. I use them as drive controls in some of my homebrew cw transceivers at a low level after the tx mixer and before the driver. May 24, 2018 the driver circuit of claim 7, wherein one or more of the receive pin diode biasing circuit, the transmit pin diode biasing circuit, and the shunt pin diode biasing circuit comprises. I have a friend who has used them in an agc circuit. At 320 mhz, the capacitive reactance of 1 pf is 497 ohms. The proposed two pin diode switch circuit and driver is experimentally tested for compliance with the desired behavior.
The bias circuit typically uses a lowpass filter between the rf circuit and the switch driver. Pin diode drivers spectrum microwave offers a complete lineup of pin diode switch drivers with output current capability of 10 ma to 50 ma and switching speeds as fast as 6 ns. We can, on special request, provide single pole ninethrow pin diode switch sp9t, single pole tenthrow pin diode switch sp10t, single pole eleventhrow pin diode switch sp11t, singlepole twelvethrow pin diode switch sp12t and can array switches to form switch matrices to handle signal routing in complex systems. A pin diode switch suitable for switching radiofrequency voltages has a series circuit of two oppositely polarized pin diodes, with a control current supplied to the junction between the two pin diodes through the collectoremitter path of a transistor and through an inductor. The amplitude of these current spikes is typical 100ma with total switching times of less than 10 ns.
How to specify pin diode switches american microwave. It is designed for spdt switches operating with a cw input a power up to 100 w. Electronic tr switching and the ameritron qsk5 circuit. Pin diode drive circuits optimized for fast switching. The necessity of using a highvoltage power pack to generate a high reverse bias in order to avoid limiting the. Drivers are typically used to translate ttl control voltages for rf and microwave attenuators and switches. When the mosfet has a low in the gate it is off so the 10k works a as a pullup and turns the transistor on to apply reverse bias to the diode under test. Once the high voltage switch is turned on, current flows from the 600v supply, through the transistor, and then through the 10k ohm resistor to the cathode side of the pin diode switch. Switches, digital and analog attenuators, and limiters each have unique functions that require proper device selection. Electronic tr switching and the ameritron qsk5 pin. Electronic tr switching and the ameritron qsk5 pin switch. A microwave pin diode is a semiconductor device that operates as a variable resistor at rf and microwave frequencies. It is also important that the specifications be achievable. Us patent application for programmable biasing for pin diode.
We present a pin diode driver which functions in both an mri scanner and nmr spectrometer. Thin film metalization on ceramic substrates ensures low parasitic capacitance for fast switching, small size, and excellent reliability. The information in this chapter is presented as a guide for the rf switch switch driver interface. The diode consists the pregion and nregion which is separated by the intrinsic semiconductor material. L3 nardamiteq designs and manufactures a broad line of digital pin diode switches covering multioctave bands from 80 mhz to 44 ghz. The seriesconnected pin diode configuration can provide reasonably low insertion loss over a multioctave frequency. The outputs of the transistors are coupled to a relatively slow d. Jun 19, 2019 thus a pin diode is a dccontrolled highfrequency resistor, and if no dc current is present, the diode is just like an open circuit. This article demonstrates how the dh0035 may be applied to driving pin diodes and comparable loads which. Design and performance of a high speed driver circuit for. Dsdfser df series decoded fast pin diode drivers 27 kb rev 111998. I have read some ap notes of pin diodes, and got to know that switching speed of my antenna switch is not only related to carrier lifetime of pin diodes,but also related to driver. The electric field induces because of the movement of the holes and the electrons.
Secondly, a section focusing on pin diode theory will be presented. The pin diodes in the switch presented either a short circuit or an open circuit, depending on the bias condition. The pin diode driver is based on readily available discrete components and achieves switching times for the reverse and forward bias states transmit on and off of 2. Jul 26, 2008 the carrier lifetime of pin diode i use is 10microsecondstyp. The driver utilizes four 2n6740 high voltage power transistors to turn the pin diode switches off and on. Pin diode driver circuits are a pain to design and build. Based on both the experimental and the data sheet information, a diode selection is made and a switch circuit is realized using two pin diodes chapter 4.
Impellimax pin diode drivers, linearizer hybrids, gaas. References 1,2 provide a fuller treatment of this subject and can be used as a basis for rf switch switch driver interface designs. This application note describes the use of pin diodes in circuit design. This transition is the slower of the two transitions in a switching application since the driver circuit is attempting to remove stored charge from the pin diode. How to build a laser diode circuit hacked by 4lf45t. The hf power coming from the tx will see 50 ohms towards the antenna, and 0r ohms towards the pin diode at both t points r is the resistance of the pin diode. Driver circuits for high power pin diode switches the information in this chapter is presented as a guide for the rf switch switch driver interface. For example, the capacitance of an offstate discrete pin diode might be 1 pf. Transistor driver circuit question no, the pin diode direction is correct. It is a silicon semiconductor diode in which a highresistivity, intrinsic i region is sandwiched between a ptype and ntype region. Part number is um4010,manufactured by microsemi corp. Nov 18, 2016 the driver circuit may further comprise an antenna contact coupled to a node between a receive pin diode and a transmit pin diode of the plural pin diodes, a receive contact coupled to a node between the receive pin diode and a shunt pin diode of the plural pin diodes, and a transmit contact coupled to the transmit pin diode, wherein the bias. Integrated biasing for pin diode drivers macom technology.
A high speed circuit was fabricated and tested to drive each pin diode switch. One of the diodes is connected in series with the sensor while the other is shunt across it and the series diode. The driver circuit of claim 7, wherein one or more of the receive pin diode biasing circuit, the transmit pin diode biasing circuit, and the shunt pin diode biasing circuit comprises. A simple untuned singlepole, single throw spst switch may be designed using either a single series or shunt connected pin diode as shown in figure 5. The goal is to maintain connection of the sensor into the series test circuit except for a short period when a trigger pulse is initiated. In a simple spst pin diode switch figure 1, the diode can be either series or shuntconnected. We have extensive experience in switch design and development for critical space, telemetry, transceiver, radar, and ew applications. How and why to use pin diodes for rf switching digikey. Infineon pin diodes come with low loss and low distortion levels and are suitable for a wide range of mobile communications and rf applications. Reverse voltage protection 30 mhz repetition ttl control protection test port short circuit protection operating characteristics. Pin diode sp4t switches from pasternack are most commonly used in rf, microwave and millimeter wave test systems for routing varying signals between instruments, allowing multiple tests to be performed at the same time using the same setup.
The high resistive layer of the intrinsic region provides the large electric field between the p and nregion. Dsucser ultracompact series ultracompact pin diode drivers 52 kb rev 112098. Series introduction this application note is intended to provide practical guidance in the selection of pin diodes for switch control circuit functions. The symbolic representation of the pin diode is shown in the figure below.
I use 1n4007 piv rectifier diodes as pin diodes in a non critical application. The switch makes use of a novel pin diode driver circuit that achieves high switching speeds while. Nov 08, 20 this is a basic tutorial on pin diodes, with some examples of how they are used in rf switch applications. Driving circuit for pin diode switches north american. Please view our large selection of pin diodes below. Here we will compare driver circuits for pin diodes with those needed for switch fets. Macoms cmos switch drivers are used extensively in wireless infrastructure base stations. At a minimum, an rf switch based on pin diodes needs a dc blocking capacitor to prevent the dc bias current from reaching the rf output, and an rf choke to provide a path for the dc bias current to. Pindiode bias interface connecting the switch driver control circuit to a pin diode such that it can turn diodes on and off by applying a forward or reverse bias is a challenging task.
The anode and cathode are the two terminal of the pin diode. The driver circuit may further comprise an antenna contact coupled to a node between a receive pin diode and a transmit pin diode of the plural pin diodes, a receive contact coupled to a node between the receive pin diode and a shunt pin diode of the plural pin diodes, and a transmit contact coupled to the transmit pin diode, wherein the bias. Too little current and the laser diode will not have sufficient power to turn on and operate. The driver utilizes fast switching npn transistors and skyworks discrete pin diodes. It is capable of delivering peak currents in excess of one ampere at speeds up to 10 mhz. Figure 5 shows a singlepole doublethrow spdt rf switch and its bias circuit. The pin diode switch driver is located on the circuit board where the high voltage lead connects to the circuit board at point e. The increase in speed over the former driver system is a factor of 5. Dsdsser ds series decoded slow 50 nsec pin diode drivers 27 kb rev 111998. Microsemis pin diode mmsm rf switches are completely compatible with pick and place and solder reflow manufacturing techniques.
Pin diode drivers introduction the dh0035dh0035c is a ttldtl compatible, dc coupled, high speed pin diode driver. The steady state current, idc, is set by rp and is given by. The current therefore flows through the base of the high voltage switch, turning it on. Application notes how to specify pin diode switches. This is a basic tutorial on pin diodes, with some examples of how they are used in rf switch applications. There are some great vendors out there that can supply you with many types of pin switch drivers commercial, military, but they will remain nameless until they pay for an ad on this page. The diode in which the intrinsic layer of high resistivity is sandwiched between the p and nregion of semiconductor material such type of diode is known as the pin diode. This page is designed to help a systems designer specify realizable pin diode switches. Because of the complexity of designing a highspeed current driver circuit, the fet switch typically has an advantage in switching speed as well. There are many unique market applications, such as the wireless communications market, where new. En33x273 this driver reference design is designed to operate with the skyworks series of highpower spdt pin diode switches. A diode alone is not a complete and useful switch as it is only the core switching element. This series of diodes can operate up to 6ghz with highvoltage handling capabilities and together with outstanding rf performance, they simplify designin because of their extreme low forward. Microsemis pin diode rf switches are optimized for uhf high power and tr switching applications in which an sp2t switch is necessary.
Thin film metalization on ceramic substrates ensures low parasitic capacitance for. This driver has complementary outputs which can provide up to 200 ma bias current to a spdt pin diode switch. A driver circuit is a circuit which can limit appropriately the amount of current being fed into the laser diode, so that it can function correctly. Pin diodes are available at mouser electronics from industry leading manufacturers. Pin diode switch circuit for short time high current pulse. Thus a pin diode is a dccontrolled highfrequency resistor, and if no dc current is present, the diode is just like an open circuit.
In this chapter theory surrounding pin diode switches and their use in rf and microwave applications will be presented. We utilize low parasitic capacitance for fast switching, small size, and excellent reliability. Figure 7shows the dh0035 driving a cathode grounded pin diode switch. Macoms cmos switch drivers are used extensively in wireless infrastructure base stations as well as aerospace and defense applications. Design and performance of a high speed driver circuit for pin. This will be followed by a section concerning the pin diode driver. The two quarter wave sections operate in identical fashion in tx mode. These spikes inject or remove carriers from the pindiode junctions. Cmos switch drivers macoms cmos switch drivers are used extensively in wireless infrastructure base stations as well as aerospace and defense applications. Figure 5 shows a singlepole doublethrow spdt rf switch. This driver is designed to provide forward currents up to 100 ma for each diode, and 28 v reverse bias. Chapter 2, the common pin diode switch configurations are presented, followed by sections comparing those features of pin diode switch designs for unique to high power microwave switches and high power lower frequency rfband switches.
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