AS

“АLFA RPAR”

Joint Stock Company ALFA

Riga, Latvia www.alfarzpp.lv; alfa@alfarzpp.lv

2018 v.5

1

AS3340

AS3345

AS3340 / AS3345 - Voltage Controlled Oscillator (VCO)

FEATURES

AS3340

AS3340D



Large Sweep Range: 500,000:1



Fully Temperature Compensated



Four Output Waveforms Available; No waveform

trimming required



Summing Node Inputs for Frequency Control



High Exponential Scale Accuracy



Low Temperature Drift



Voltage Controlled Pulse Width



Hard and Soft Sync Inputs



Linear FM



Buffered, Short Circuit Protected Outputs



±15 Volt Supplies

РDIP-16 (300 mil)

SOIC-16 (150 mil)

AS3345

AS3345F

РDIP-18 (300 mil)

QFN-24 4x4 mm 0,5 mm

APPLICATIONS

for electronic music

General Description

The AS 3340 and AS 3345 are completely self contained, precision voltage controlled oscillators, featuring both exponential

and linear control scales and up to four buffered output waveforms: triangle, sawtooth, square, and pulse with voltage

controllable pulse width. Full temperature compensation makes these VCOs extremely stable, and eliminates the need for a

temperature compensation resistor. The highly accurate exponential and linear control inputs are virtual ground summing nodes,

allowing multiple control voltages to be mixed within the device itself.

Also included is provision for hard and soft synchronization of the frequency, and an output for easy adjustment of high

frequency tracking. Special care in the design ensures oscillation start-up under any power-on sequence and supply conditions.

An on-chip 7.4

volt Zener diode allows the device to operate off ±15 volt supplies, as well as +15,-5 volt supplies. For voltages

greater than -7.5 volts, a series current limiting resistor must be added between pin 3 and the negative supply. Its value is

calculated as follows:

Power pad in QFN package highly improves thermal stability of parameters of AS3345F.

AS3340 Pin Information

AS3340 Circuit Block and Connection Diagram

РDIP-16,

SOIC-16

Pin No

Pin

Name

Description

1

Scale 1 Scale Adjust 1

2

Scale 2 Scale Adjust 2

3

Negative supply

4

Pulse Output

5

PWM Control Input

6

Hard Synchronization

Input

7

High Frequency

Track

8

Sawtooth Output

9

Input

10

Triangle Output

11

Cap

Capacitor

12

GND

Ground

13

Linear FM Input

14

Scale

15

Frequency Control

Input

16

Positive supply

470



10nF

1M

TOP

VIEW

4

5

6

7

8

9

10

11

12

13

14

15

16

1

+15V

2

3

FREQ. CNTL.

INPUTS

LINEAR FM

INPUT

SOFT

SYNC.

INPUT

0V

+5V

+15V

+15V

1.5M

1M

10nF

100nF

1.8K

470



PRECISION

MULTIPLIER

1nF

Q1

A2

- +

V+

CM

CM

+ -

V+

A1

4X

4X

1X

Q3

Q2

1nF

-1.3V

BUF

- +

+ -

14.4K

V+

TRI.

TO

SAW

CONV.

HIGH

FREQ.

TRACK

1nF

20K

HARD

SYNC.

INPUT

P.W.M.

CNTL.

INPUT

0V

+12V

+10V

-15V

820



51K

10K

24K

5.6K

7.4V

V-

V+

-

+

TEMPCO

GEN

0V