 |
Os motores de busca de Datasheet de Componentes eletrônicos |
|
|
Os motores de busca de Datasheet de Componentes eletrônicos |
|
AD831AP Folha de dados(PDF) 7 Page - Analog Devices |
|
||||||||||||||||||||||||||||||
AD831AP Folha de dados(HTML) 7 Page - Analog Devices |
|
|
7 / 16 page  AD831 REV. B –7– THEORY OF OPERATION The AD831 consists of a mixer core, a limiting amplifier, a low noise output amplifier, and a bias circuit (Figure 17). The mixer’s RF input is converted into differential currents by a highly linear, Class A voltage-to-current converter, formed by transistors Q1, Q2 and resistors R1, R2. The resulting currents drive the differential pairs Q3, Q4 and Q5, Q6. The LO input is through a high gain, low noise limiting amplifier that converts the –10 dBm LO input into a square wave. This square wave drives the differential pairs Q3, Q4 and Q5, Q6 and produces a high level output at IFP and IFN—consisting of the sum and difference frequencies of the RF and LO inputs—and a series of lower level outputs caused by odd harmonics of the LO fre- quency mixing with the RF input. An on-chip network supplies the bias current to the RF and LO inputs when these are ac coupled; this network is disabled when the AD831 is dc coupled. When the integral output amplifier is used, pins IFN and IFP are connected directly to pins AFN and AFP; the on-chip load resistors convert the output current into a voltage that drives the output amplifier. The ratio of these load resistors to resistors R1, R2 provides nominal unity gain (0 dB) from RF to IF. The expression for the gain, in decibels, is GdB = 20 log10 4 π 1 2 π 2 Equation 1 where 4 π is the amplitude of the fundamental component of a square wave 1 2 is the conversion loss π 2 is the small signal dc gain of the AD831 when the LO input is driven fully positive or negative. 20 2 Q3 R5 1k Ω LIMITING AMPLIFIER 16 AO 17 CURRENT MIRROR VP 50 Ω 50 Ω 20 Ω 20 Ω BIAS 18mA TYP IFN AN AP IFP 19 3 18mA TYP 5k Ω 5k Ω Q1 Q2 Q5 Q6 Q4 R4 1k Ω R1 20 Ω R2 20 Ω R3 26 Ω Q7 BIAS 36 Ω 50 Ω 50 Ω 18 OUT VFB COM 12mA TYP 36mA TYP 27mA TYP LOP LON RFP RFN VP BIAS VN LOCAL OSCILLATOR INPUT RF INPUT 1 10 11 6 7 BIAS CURRENT Figure 17. Simplified Schematic Diagram |
Nº de peça semelhante - AD831AP |
|
Descrição semelhante - AD831AP |
|
|
|
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
