1 2 3 4 5 6 7 5V ECO __ V+OA J3 MUTE 8 VCO- 3.3V L2 68nH 0402HPH-68NXJL 35V 0805 18 17 16 ASSY * U3 -A CVCO55CC-2328-2536 R30 0 1uF 10 9 C28 OPT L1_F3 OPT 0805 U3 R2_F2 0 0603 * GND GND GND VTUNE RFOUT GND GND GND C35 0.1uF R2_F3 OPT 0603 U4 2 3 OPT VTUNE EN NC GND C33 E15 47uF 35V 7361 E16 35V 0805 6 R23 VCC OPT 5 RFOUT 1 4 V+VCO GND B V+VCXO GND 4 R24 OPT 2 C3_F2 OPT 0603 CPGAIN OPT V+VCXO 1 3 CPGAIN C3_F3 OPT 0603 E17 E18 GND C EN C25 OPT J5 EXT VCO IN L1 OPT RF+ J7 J6 CUSTOMER NOTICE VCO NOTE: UNLESS OTHERWISE SPECIFIED 1. ALL RESISTORS ARE IN OHMS, 0402 2. ALL CAPACITORS ARE IN MICROFARADS, 0402. THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 3 4 5 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only APPROVALS LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES. VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APP ENG. APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. 2328 - 2536 MHz 2 11 E13 C34 0.01uF C45 0.01uF C38 100pF RF- 1 C26 100pF 15 12 C19 47uF 35V 7361 + 19 L3 3.3V 68nH 0402HPH-68NXJL C37 100pF D C21 0.1uF 20 0603 JP1 L1_F2 OPT 0805 V+VCO 21 C29 100pF 3.3V C31 CI2_P OPT 1206 J4 E14 16 V+D 0603 RZ_P 21 0603 CI1_P 1uF 0603 0 + A GND R13 OPT GND VCO+ 3.3V GND CP_P 47nF 0603 C23 0.01uF 23 GNDH 25 24 V+CP 27 26 CP V+REF LDO C30 0.1uF 3.3V REF- GNDB MUTE 3.3V R29 0 SDO 9 C C11 0.1uF GNDC 5V J11 GND 7 SDI C16 330uF 10V 7343 V+VCO CI2_A OPT 1206 R14 BB 6 GNDD V+RF 5 GNDE SCLK + 0603 22 GNDF CS RF+ 4 13 CS SCLK SDI SDO C13 1uF 0603 E12 3.3V U1 LTC6947IUFD GNDG QFN28UFD-4X5 STAT 12 3 RF- 2 REF+ GNDA 1 11 RED C14 OPT 0603 28 29 2 10 1 C18 1uF 0603 R27 0 GND E6 STATUS D1 LN1251CTR R4 330 E11 5 C15 1uF C8 1uF B C17 0.01uF 01-28-14 V+OA 5V 5 +INB DATE MICHEL A. CI1_A OPT 0603 RZ_A OPT 0603 R28 0 V+VCO C4 0.1uF R5 51.1 14 J2 C1 47uF 35V 7361 APPROVED CP_A OPT 0603 5V R25 0 REF+ PRODUCTION J12 0603 3.3V DESCRIPTION 2 0603 R16 0 14 0603 V- + REV 35V 0805 6 -INB B 15 0805 0603 J10 20V 7343 A +INA 4 VCC R1_F1 21 3 GND L1_F1 0 47uF 7 OUTB GND C5 1uF 0603 C7 R15 OPT C2 0.1uF 8 V+ GND GND C2_F1 33nF -INA 13 + C3 330uF 10V 7343 OUTA 2 GND J9 1 0.1uF + 3.3V C6 R31 OPT 0603 6 3.3V U2 LT1678IS8 GND CP OPT R2 4.99K 7 A E3 C12 1uF 0603 R1 4.99K 8 CP 8 REVISION HISTORY TECHNOLOGY KIM T. TITLE: SCHEMATIC MICHEL A. ULTRALOW NOISE AND SPURIOUS FRACTIONAL-N SYNTHESIZER SIZE N/A SCALE = NONE 6 DATE: LTC6947IUFD IC NO. REV. 2 DEMO CIRCUIT 1846A 01/28/2014, 12:25 PM 7 SHEET 1 8 OF 2 D A B C D E DC590B SPI INTERFACE 3.3V 4 J13 HD2X7-079-MOLEX 1 6 3 4 2 2 WP R8 200K 5 3.3V 6 C41 4 SCLK 0.1uF 3 4 VCC 3.3V 5 SDI C44 0.1uF 3 8 GND R12 100 U11 74LVC1T45GW C36 0.1uF 1 VCC(A) 2 GND 3 R9 0 0603 EEGND 1 2 VCC SCL SDA WP A2 A1 A0 C43 0.1uF 4 13 8 3 6 5 7 3 2 1 U8 24LC025-I /ST R7 200K GND R26 4.99K ARRAY R20 4.99K GND GND GND R11 4.99K EEPROM 10 9 11 12 14 EEVCC EESDA EESCL EEGND AUX VCC CS R22 100 U10 NC7WZ17P6X 6 4 7 5 CS SCK/SCL MOSI/SDA MISO GND R21 100 V+DIG CS SCLK SDI SDO 1 2 V+ 5V 3 U5 NC7WZ17P6X R19 200K 3.3V VCC(B) 6 DIR 5 C39 0.1uF 4 SDO 2 R18 200K NOTE: EEPROM FOR BOARD IDENTIFICATION CUSTOMER NOTICE APPROVALS LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES. KIM T. VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APP ENG. MICHEL A. APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. 1 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. A B C TECHNOLOGY TITLE: SCHEMATIC 1 ULTRALOW NOISE AND SPURIOUS FRACTIONAL-N SYNTHESIZER SIZE LTC6947IUFD IC NO. N/A SCALE = NONE 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only DATE: REV. DEMO CIRCUIT 1846A 01/28/2014, 12:25 PM D SHEET 2 E 2 OF 2