 |
Os motores de busca de Datasheet de Componentes eletrônicos |
|
|
Os motores de busca de Datasheet de Componentes eletrônicos |
|
AD8319ACPZ-WP Folha de dados(PDF) 11 Page - Analog Devices |
|
||||||||||||||||||||||||||||||
AD8319ACPZ-WP Folha de dados(HTML) 11 Page - Analog Devices |
|
|
11 / 20 page  AD8319 Rev. A | Page 11 of 20 USING THE AD8319 BASIC CONNECTIONS The AD8319 is specified for operation up to 10 GHz, as a result, low impedance supply pins with adequate isolation between functions are essential. A power supply voltage of between 3.0 V and 5.5 V should be applied to VPOS. Power supply decoupling capacitors of 100 pF and 0.1 μF should be connected close to this power supply pin. AD8319 1 2 3 4 8 7 6 5 SIGNAL INPUT R1 52.3Ω R2 0Ω R4 0Ω C2 C1 C5 C4 47nF 47nF 0.1µF 100pF VS(3.0V TO 5.5V) INHI INLO VPOS TADJ VOUT COMM CLPF VSET * * VOUT *SEE THE TEMPERATURE COMPENSATION OF OUTPUT VOLTAGE SECTION. Figure 22. Basic Connections The paddle of the LFCSP is internally connected to COMM. For optimum thermal and electrical performance, the paddle should be soldered to a low impedance ground plane. INPUT SIGNAL COUPLING The RF input (INHI) is single-ended and must be ac-coupled. INLO (input common) should be ac-coupled to ground. Suggested coupling capacitors are 47 nF ceramic 0402-style capacitors for input frequencies of 1 MHz to 10 GHz. The coupling capacitors should be mounted close to Pin INHI and Pin INLO. The coupling capacitor values can be increased to lower the input stage’s high-pass cutoff frequency. The high- pass corner is set by the input coupling capacitors and the internal 10 pF high-pass capacitor. The dc voltage on INHI and INLO is about one diode voltage drop below VPOS. VPOS 2kΩ A = 9dB 18.7kΩ 18.7kΩ CURRENT Gm STAGE INLO INHI OFFSET COMP 5pF 5pF FIRST GAIN STAGE Figure 23. Input Interface While the input can be reactively matched, in general this is not necessary. An external 52.3 Ω shunt resistor (connected on the signal side of the input coupling capacitors, as shown in Figure 22) combines with the relatively high input impedance to give an adequate broadband 50 Ω match. The coupling time constant, 50 × CC/2, forms a high-pass corner with a 3 dB attenuation at fHP = 1/(2π × 50 × CC ), where C1 = C2 = CC. Using the typical value of 47 nF, this high-pass corner is ~68 kHz. In high frequency applications, fHP should be as large as possible to minimize the coupling of unwanted low frequency signals. In low frequency applications, a simple RC network forming a low-pass filter should be added at the input for similar reasons. This should generally be placed at the generator side of the coupling capacitors, thereby lowering the required capacitance value for a given high-pass corner frequency. OUTPUT INTERFACE The VOUT pin is driven by a PNP output stage. An internal 10 Ω resistor is placed in series with the output and the VOUT pin. The rise time of the output is limited mainly by the slew on CLPF. The fall time is an RC-limited slew given by the load capacitance and the pull-down resistance at VOUT. There is an internal pull-down resistor of 1.6 kΩ. A resistive load at VOUT is placed in parallel with the internal pull-down resistor to provide additional discharge current. + 0.8V 1200Ω 400Ω – 10Ω VOUT VPOS CLPF COMM Figure 24. Output Interface To reduce the fall time, VOUT should be loaded with a resistive load of <1.6 kΩ. For example, with an external load of 150 Ω, the AD8319 fall time is <7 ns. SETPOINT INTERFACE The VSET input drives the high impedance input (20 kΩ) of an internal op amp. The VSET voltage appears across the internal 1.5 kΩ resistor to generate ISET. When a portion of VOUT is applied to VSET, the feedback loop forces −ID × log10(VIN/VINTERCEPT) = ISET (2) If VSET = VOUT/2x, ISET = VOUT/(2x × 1.5 kΩ). The result is VOUT = (−ID × 1.5 kΩ × 2x) × log10(VIN/VINTERCEPT) 1.5kΩ ISET COMM VSET VSET COMM 20kΩ 20kΩ Figure 25. VSET Interface |
Nº de peça semelhante - AD8319ACPZ-WP |
|
Descrição semelhante - AD8319ACPZ-WP |
|
|
|
Ligação URL |
| Privacy Policy |
| ALLDATASHEETPT.COM |
| ALLDATASHEET é útil para você? [ DONATE ] |
Sobre Alldatasheet | Publicidade | Contato conosco | Privacy Policy | roca de Link | Lista de Fabricantes All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
|
Family Site : ic2ic.com |
icmetro.com |
Portuguese ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
