Cem 3340

A) Check for about 40mv of signal on U22 pins 2 t 3. Go to STEP 12 if signals are not present.

B) Short 013 collector to ground (BASE) and check for signal on U22 Pin 6. Replace U22 if no signal is present.

C) Replace 013 if signal is present.

A) Verify VCF is working,. STEP 9 and 12.

B) Short 012 collector to ground and check VCF at 020 Pins 1 and 7 for sine wave oscillation.

C) If no oscillation is present replace U20 and go to STEP 15B.

D) Replace C28 through 31 and go to STEP 15B.

E) Replace 012.

Voltage Controlled Oscillator

Absolute Maximum Ratings

The CEM 3340 and CEM 3345

are completely «»M contained, preciiior voltagf controlled otcillato's, featuring both exponential and lir>e»t control aeales and uc to fou' buffered output waveformi triangle, »wtooth, souare. and pulse with volta^ controllable pulse width. Full temperature compensation makes these VCOs extremely «table, and eliminates the need fc a temperature compensation resisto- Tne hign-'y accurate exponent.a' and lines- control inputs 3'f virtus' g'ojnd summing nodes, allowing mul tiple control voltages to be mixed within the device iaelf.

Also included is provision for hard and toft synchronization of the frequency, and an output for easy adiustment of high frequency tracking Special care in the design ensures oscillation tun-up under any power-on aequence and supply conditions.

Although a low voltage process has been used to reduce die site, cost, and leakage currents, an on-chip 6.5 volt liner diode allows the device to pperate off ±15 volt supplies, as well as *15,-5 volt supplies.

Volttge Between Vcc »r>d VEE Pirn


Voltage Between Vcq and Ground Pins


Voltage Between Vj£ and Ground Pins


Voltage Between frequency Control Pin pr Reference Current Pin and Ground Pin


Voltage Between Multiplier Output Pin and Ground Pin


Currant through Any Pin


Storage Temperature Range


Operating Temperature Range


CEM 3340 Circuit Block and Connection Diagram

Philips Pm3234 Circuit

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