Linear Technology DC814, Quick Start Manual

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DC814 QUICK START QUIDE
4
QUICK START PROCEDURE
Test Procedure: Buffer Board w ith DIP-8 Clock
Test Equipm ent:
A. a single pow er supply, 3V to 5V.
B. an oscilloscope w ith a bandw idth of at least
10x the highest clock IC frequency (for example, the highest fre-
quency of the LTC6905 is 170M Hz and the oscilloscope bandw idth
should be at least 1.7GHz).
C. a frequency counter
D. a potentiometer screw driver
E. a resistance meter
A. Test Procedure for the R esistor SET ICs:
IC Buffer Board
LTC6905 DC814A-A
LTC1799 DC814A-B
LTC6900 DC814A-C
LTC6906 DC814A-H
LTC6907 DC814A-I
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 3).
3. Connect a resistance meter from the V+ turret to pin 1 of the
buffer board socket (see figure 4). Adjust the buffer board potenti-
ometer (R SET1) to set the total resistance (R SET1 plus R SET2) for
the desired frequency. Table 3 show s the equation for R SET
(R SET1 plus R SET2). The resistor designator for the R SET resistor
on the DIP-8 clock board is R S1.
Note: The frequency adjustment is very coarse w hen the potenti-
ometer is turned near the fully clockw ise position.
4. Connect buffer board to a single pow er supply and an oscillo-
scope as show n in Figure 4 (the oscilloscope input should be set
to 50 ohms impedance internally or terminated externally w ith a
50 ohm BN C thru terminator).
5. Insert the DIP-8 clock board on the buffer board and turn on the
pow er supply.
6. The oscilloscope w aveform should be a 0V to V+/2 squarew ave
(the output of the clock is divided by tw o by 50 ohms in series
w ith the buffer output and the 50 ohm oscilloscope input).
7. Connect the buffer board CLKOU T to a frequency counter to
measure the frequency precisely (the maximum frequency error at
25
°
C is listed in Table 3).
B. Test Procedure for the Fixed Frequency ICs:
IC Buffer Board
LTC6905-133 DC814A-D
LTC6905-100 DC814A-E
LTC6905-96 DC814A-F
LTC6905-80 DC814A-G
1. Connect buffer board w ith the DIP-8 clock to a single pow er
supply and an oscilloscope as show n in Figure 4 (the oscilloscope
input should be set to 50 ohms impedance internally or terminated
externally w ith a 50 ohm BN C thru terminator).
2. Turn on the pow er supply.
3. The oscilloscope w aveform should be a 0V to V+/2 squarew ave
(the output amplitude of the clock is divided by tw o by 50 ohms in
series w ith the buffer output and the 50 ohm oscilloscope input).
4. Connect the buffer board CLKOU T to a frequency counter to
measure the frequency precisely (the maximum frequency error at
25
°
C is listed in Table 3).
C. Test Procedure for the VCO function of LTC6905 (D C814A-A),
LTC1799 (D C814A-B) and LTC16900 (D C814A-C).
1. Turn potentiometer R SET1 fully clockw ise and set the JP2
shunt on the DIP-8 clock board to 1-2.
2. Connect a voltage source to the buffer board’s VIN input
(refer to Figure 5) and turn on pow er.
3. Typical VCO voltage (VCTR L) and Frequency range: