DC814 LTC1799 LTC6900 LTC6905 LTC6905-XXX LTC6906 LTC6907 LTC6908-X DC814D-J

DEMO CIRCUIT DC814 QUICK START GUIDE SILICON OSCILLATOR DEMONSTRATION CIRCUIT: LTC1799, LTC6900, LTC6905, LTC6905-XXX, LTC6906,

DC814 DC814 QUICK START GUIDE DEMO CIRCUIT DC814 DC814 QUICK START GUIDE SILICON OSCILLATOR DEMONSTRATION CIRCUIT: LTC1799 LTC1799, LTC6900 LTC6900, LTC6905 LTC6905, LTC6905-XXX LTC6905-XXX, LTC6906 LTC6906, LTC6907 LTC6907, LTC6908-X LTC6908-X DESCRIPTION Demonstration circuit DC814 DC814 provides a simple evaluation circuit for Linear Technology's resistor-set and fixed frequency silicon oscillators. For each silicon oscillator, there are two demo boards: Board 1, a DIP-8 Clock Board (a silicon oscillator is mounted on this board). Board 2, a Buffer Board (a board with a high speed driver for the DIP-8 Clock Board). DIP-8 CLOCK BOARDS A DIP-8 Clock Board is a small printed circuit board containing a silicon oscillator that is pin compatible with "half-size" canned crystal oscillators (13mm X 13mm). For the resistorsettable versions, the DIP-8 Clock Boards have surface mount pads for installing 0603 size resistors to program the output frequency (RS1 on clock board). A unique Buffer Board is available for each DIP-8 Board (see Table 2). A high-speed driver with a maximum output current of ±100mA buffers the output of the DIP-8 clock. The output of the buffer is connected through a 50ohm resistor to a BNC connector for driving 50-ohm coaxial cables. NOTE: The DC814D-J DC814D-J and DC814D-K DC814D-K (DIP-8 Clock Boards for the LTC6908-1 LTC6908-1 & LTC6908-2 LTC6908-2) have an additional output (OUT2). The user can install a pin for access to this output. However, the DIP-8 board will not fit into the buffer board with an installed pin for OUT2. The user must bend this pin or install a 90° pin to use the DC814D-x DIP-8 Clock Boards with the buffer boards. Design files for this circuit board are available. Call the LTC factory. , LTC and LT are registered trademarks of Linear Technology Corporation. All of the resistor-settable oscillators, except for the LTC6908x, have a divider input. For these DIP-8 Clock Boards, an optional jumper is provided to set the divider value. The LTC6905-xxx series are fixed frequency oscillators and their DIP-8 Clock Boards do not require a frequency setting resistor. The LTC6908-x boards have a modulation control input (MOD) and the corresponding DIP-8 Clock Boards provide an optional jumper to configure the spread spectrum frequency modulation (SSFM). A jumper can be used to disable the SSFM or set the rate to 1 of 3 rates (see datasheet for details on the SSFM rate selection). A DIP-8 Board is ordered independently (see Table 1). BUFFER BOARDS The Buffer Boards contain a buffering circuit designed specifically for DIP-8 Clock Boards. The DIP-8 Clock Board mounts onto a DIP-8 socket on the Buffer Board. A multi-turn potentiometer on the Buffer Board is provided to adjust oscillator frequency of a DIP-8 Clock Board (a potentiometer is not required for the LTC6905-X LTC6905-X series). Table 1. DIP-8 Clock Board Part Numbers DIP-8 Clock Board DC814B-A DC814B-A Clock IC LTC6905 LTC6905 DC814B-B DC814B-B LTC1799 LTC1799 DC814B-C DC814B-C DC814B-D DC814B-D DC814B-E DC814B-E DC814B-F DC814B-F LTC6900 LTC6900 LTC6905-133 LTC6905-133 LTC6905-100 LTC6905-100 LTC6905-96 LTC6905-96 DC814B-G DC814B-G DC814C-H DC814C-H DC814C-I DC814C-I DC814D-J DC814D-J LTC6905-80 LTC6905-80 LTC6906 LTC6906 LTC6907 LTC6907 LTC6908-1 LTC6908-1 DC814D-K DC814D-K LTC6908-2 LTC6908-2 1 DC814 DC814 QUICK START GUIDE Table 2. Buffer Board Part Numbers Buffer Board* DC814A2-A DC814A2-A Clock IC LTC6905 LTC6905 DC814A2-B DC814A2-B DC814A2C DC814A2C DC814A2-D DC814A2-D DC814A2-E DC814A2-E LTC1799 LTC1799 LTC6900 LTC6900 LTC6905-133 LTC6905-133 LTC6905-100 LTC6905-100 DC814A2-F DC814A2-F DC814A2-G DC814A2-G DC814A2-H DC814A2-H LTC6905-96 LTC6905-96 LTC6905-80 LTC6905-80 LTC6906 LTC6906 DC814A2-I DC814A2-I DC814A2-J DC814A2-J DC814A2-K DC814A2-K LTC6907 LTC6907 LTC6908-1 LTC6908-1 LTC6908-2 LTC6908-2 * A DC814A2-X DC814A2-X is version two of the Buffer Board. The first release of the Buffer Board is DC814A-X DC814A-X and is compatible with a DIP-8 Clock Board. Figure 1. DC814B-X DC814B-X DIP-8 Clock Board (Top side view) 2 Figure 2. DC814C-X DC814C-X DIP-8 Clock Board (Top side view) Figure 3. DC814D-X DC814D-X DIP-8 Clock Board (Top side view) DC814 DC814 QUICK START GUIDE 1. Remove DIP-8 clock board from buffer board 2. Set the jumper shunt on the DIP-8 clock board to the divider value, N, for the frequency range of interest (refer to Table 5). NOTE: On DC814D-J DC814D-J or K DIP-* board only N=1 is available in the JP1 1-2 position with spread spectrum modulation disabled. JP1 positions 3-4, 5-6 and 7-8 set the spread spectrum modulation rate to fout/16, fout/32 and fout/64 respectively. Figure 4. The DC814A2-X DC814A2-X Buffer Board QUICK START PROCEDURE TEST PROCEDURE: BUFFER BOARD WITH DIP-8 CLOCK Test Equipment: 1. A single power supply, 3V to 5V. 2. An oscilloscope with a bandwidth of at least 10x the highest clock IC frequency (for example, the highest frequency of the LTC6905 LTC6905 is 170MHz and the oscilloscope bandwidth should be at least 1.7GHz). 3. A frequency counter 4. A potentiometer screwdriver 5. A resistance meter 1. Test Procedure for the Resistor SET ICs: IC LTC6905 LTC6905 LTC1799 LTC1799 LTC6900 LTC6900 LTC6906 LTC6906 LTC6907 LTC6907 LTC6908-1 LTC6908-1 LTC6908-2 LTC6908-2 Buffer Board DC814A-A DC814A-A DC814A-B DC814A-B DC814A-C DC814A-C DC814A-H DC814A-H DC814A-I DC814A-I DC814A-J DC814A-J DC814A-K DC814A-K 3. Connect a resistance meter from the V+ turret to pin 1 of the buffer board socket (see figure 4). Adjust the buffer board potentiometer (RSET1) to set the total resistance (RSET1 plus RSET2) for the desired frequency. Table 5 shows the equation for RSET (RSET1 plus RSET2). The resistor designator for the RSET resistor on the DIP-8 clock board is RS1. NOTE: The frequency adjustment is very coarse when the potentiometer is turned near the fully clockwise position. 4. Connect buffer board to a single power supply and an oscilloscope as shown in Figure 6 (the oscilloscope input should be set to 50 ohms impedance internally or terminated externally with a 50 ohm BNC thru terminator). 5. Insert the DIP-8 clock board on the buffer board and turn on the power supply. 6. The oscilloscope waveform should be a 0V to V+/2 squarewave (the output of the clock is divided by two by 50 ohms in series with the buffer output and the 50 ohm oscilloscope input). 7. Connect the buffer board CLKOUT to a frequency counter to measure the frequency precisely (the maximum frequency error at 25 °C is listed in Table 5). 3 DC814 DC814 QUICK START GUIDE 2. Test Procedure for the Fixed Frequency ICs. IC LTC6905-133 LTC6905-133 LTC6905-100 LTC6905-100 LTC6905-96 LTC6905-96 LTC6905-80 LTC6905-80 Buffer Board DC814A-D DC814A-D DC814A-E DC814A-E DC814A-F DC814A-F DC814A-G DC814A-G Figure 5. Buffer Board VCO circuit LTC6905 LTC6905 V+=3V, VCNTR: 0V-2V Frequency Range: 102.5MHz 186.1MHz RSET = 9.09k and RIN = 40.2k, N=1 1. Connect buffer board with the DIP-8 clock to a single power supply and an oscilloscope as shown in Figure 6 (the oscilloscope input should be set to 50 ohms impedance internally or terminated externally with a 50 ohm BNC thru terminator). Turn on the power supply. V+=3V, VCNTR: 0V-2V V+=5V, VCNTR: 0V-4V Frequency Range: Frequency Range: 18.1MHz 31.5MHz LTC1799 LTC1799 8.5MHz 31.5MHz RSET = 3.01k and RIN = 14.7k, N=1 V+=3V, VCNTR: 0V-2V V+=5V, VCNTR: 0V-4V Frequency Range: Frequency Range: 12.1MHz 21.5MHz LTC6900 LTC6900 4.8MHz 21.5MHz RSET = 9.09k and RIN = 40.2k, N=1 2. The oscilloscope waveform should be a 0V to V+/2 squarewave (the output amplitude of the clock is divided by two by 50 ohms in series with the buffer output and the 50 ohm oscilloscope input). 3. Connect the buffer board CLKOUT to a frequency counter to measure the frequency precisely (the maximum frequency error at 25 °C is listed in Table 4). 3. Test Procedure for a VCO circuit. LTC6905 LTC6905 (DC814A-A DC814A-A), LTC1799 LTC1799 (DC814A-B DC814A-B) and LTC6900 LTC6900 (DC814A-C DC814A-C). 1. Turn potentiometer RSET1 fully clockwise. 2. Connect a voltage source to the buffer board's VIN (VCNTRL) input (refer to Figure 5) 3. Set the V+ voltage to the buffer board to 3V or 5V and the JP2 jumber on the DIP-8 board in the divide by 1 position (JP2 1-2 for LTC6905 LTC6905 and JP2 5-6 for LTC1799 LTC1799 and LTC6900 LTC6900). NOTE: The typical VCO control voltage range depends on the clock IC, the ratio of the RSET and RIN resistors and the V+ voltage. VCO operation is not guaranteed if the VCO voltage forces the clock's frequency outside the frequency range shown on Table 3. Refer to the LTC6905 LTC6905 data sheet for a VCO design guide or to a May 2002 Linear Technology Magazine article: How to use the LTC6900 LTC6900 as a VCO. 4 Figure 5. Buffer Board VCO circuit DC814 DC814 QUICK START GUIDE Table 4. Frequency Accuracy for Fixed Frequency Oscillators LTC6905-133 LTC6905-133 (Board Version D) LTC6905-96 LTC6905-96 (Board Version F) N = 1, 133MHz; N = 2, 66.7MHz; N = 4, 33.5MHz N = 1, 96MHz; N = 2, 48MHz; N = 4, 24MHz Maximum Frequency Error at 25 °C: ±1.0% at V+=2.7V to 3.6V and ±1.5% Maximum Frequency Error at 25 °C: ±1.0% at V+=2.7V to 3.6V and ±1.5% typical at V+=5 typical at V+=5V LTC6905-100 LTC6905-100 (Board Version E) LTC6905-80 LTC6905-80 (Board Version G) N = 1, 133MHz; N = 2, 66.7MHz; N = 4, 33.5MHz N = 1, 80MHz, N = 2, 40MHz; N = 4, 20MHz Maximum Frequency Error at 25 °C: ±1.0% at V+=2.7V to 3.6V and ±1.5% Maximum Frequency Error at 25 °C: ±1.0% at V+=2.7V to 3.6V and ±1.5% typical at V+=5V typical at V+=5V 5 DC814 DC814 QUICK START GUIDE Table 5. Frequency Range and Accuracy of Resistor SET Oscillators. LTC6905 LTC6905 (Board Version A) RSET = 3370/(2·Fosc·N-3), LTC6906 LTC6906 (Board Version H) RSET = 100/(Fosc·N), (Fosc is in MHz and RSET in k) (Fosc in MHz and RSET in k) N = 1, 69MHz fosc170MHz (JP2 1-2) N = 1, 0.1MHz fosc 1MHz (JP2 5-6) N = 2, 34MHzfosc85MHz (JP2 3-4) N = 3, 33kHzfosc333kHz (JP2 3-4) N = 4, 17MHzfosc42MHz (JP2 5-6) N = 10, 10kHzfosc 100kHz (JP2 1-2) Max Frequency Error at 25 °C: Max Frequency Error at 25 °C: ±1.4% at V+=2.7V to 3.6V and ±2.2% at V+=5V ±0.5% at V+=2.7V to 3.6V LTC1799 LTC1799 (Board Version B) LTC6907 LTC6907 (Board Version I) RSET = 100/(Fosc·N), RSET = 200/(Fosc·N), (Fosc in MHz and RSET in k) (Fosc in MHz and RSET in k) N = 1, 0.1MHzfosc33MHz (JP2 5-6) N = 1, 0.4MHzfosc4MHz N=10, 10kH fos3.3MHz (JP2 3-4) N = 3, 133MHzfosc1.33MHz (JP2 3-4) N = 100, 1kHz fosc330kHz (JP2 1-2) N = 10, 40 kHzfosc400kHz Max Frequency Error at 25 °C: (JP2 1-2) Max Frequency Error at 25 °C: ±1.5% at V+=3V and ±1.5% at V+=5V (JP2 5-6) ±0.5% at V+=2.7V to 3.6V LTC6900 LTC6900 (Board Version C) RSET = 200/(Fosc·N) LTC6908-1 LTC6908-1 (Board Version J) RSET = 100/(Fosc) (Fosc in MHz and RSET in k) (Fosc in MHz and RSET in k) N=1 (JP1 1-2 or STOP position with spread spectrum modulation disabled) N = 1, 0.1MHzfosc20MHz (JP2 5-6) Max Frequency Error at 25 °C: N = 10, 10kHzfosc2MHz (JP2 3-4) ±2% at V+=2.7V to 5V (50kHz to 10MHz) N = 100, 1kHzfosc200kHz (JP2 1-2) Max Frequency Error at 25 °C: ±1.5% at V+=3V and ±1.5% at V+=5V LTC6908-2 LTC6908-2 (Board Version K) RSET = 100/(Fosc) (Fosc in MHz and RSET in k) N=1 (JP1 1-2 or STOP position with spread spectrum modulation disabled) Max Frequency Error at 25 °C: ±2% at V+=2.7V to 5V (50kHz to 10MHz) 6 DC814 DC814 QUICK START GUIDE 7 DC814 DC814 QUICK START GUIDE 8 DC814 DC814 QUICK START GUIDE 9 DC814 DC814 QUICK START GUIDE 10