MAX038 chip waveform Generator

China Product


0 Introduction


Waveform generator with wide applications. In the analysis testing equipment, ultrasonic equipment, medical equipment and communications equipment widely used.


Function generator as the excitation source signal, the parameter accuracy is an important factor to be considered in the design. Common waveform generation circuit RC oscillator circuit, LC oscillator circuit, oscillation circuit and the venturi formed by the 555-chip oscillation circuit, but the oscillator circuit chip as the core, frequency selection and restrictions limiting device characteristics, the amplitude and frequency accuracy There is more or less respect or realization of the circuit unstable and complex situations. If you need to achieve wave transformation, the size of amplitude and frequency adjustment and improve the stability of amplitude and frequency, the design of peripheral circuits will become more complex. Formed by the MAX038 waveform generator circuit designed to output a high amplitude-frequency accuracy and easy adjustment of the waveform signal, the circuit parameters demanding workplace can be a good application.
solenoid actuator


1 Chip Features
led scrolling message


1.1 MAX038 chip performance characteristics


20-pin DIP chip MAX038CPP package, pin diagram shown in Figure 1. The pin functions are summarized below:


REF: chip 2.5 V reference voltage output;


GND: Analog ground;


A1, A0: output waveform selected, TTL / CMOS compatible;


COSC: internal oscillator, external capacitors;


FADJ, DADJ: output frequency, duty cycle adjustment;


IIN: oscillation frequency control current input;


PDI, PDO: internal phase detector input and output;


SYNC: synchronization signal output, allowing simultaneous internal oscillator and the external circuit;


DGND, DV +: internal digital circuit power;


V +, V-: MAX038 Power Supply (+5 V, -5 V);


OUT: output waveform.


Add a little MAX038 chip peripheral circuits can generate triangle wave, sawtooth, sine, square, rectangular pulse shape. The chip has the following features:


(1) Output frequency range: 0.1 ~ 20 MHz, up to 40 MHz:


(2) Output waveform duty cycle (15% ~ 85%) independent variable, the duty cycle can be DADJ end adjustments, if DADJ grounded, the output duty cycle is 50%;


(3) with low output impedance of the output buffer, the output impedance of the typical value of 0.1 ;


(4) with TTL separate sync signal compatible SYNC (square-wave output, 50% fixed duty cycle) to facilitate the formation of the frequency synthesizer system;


(5) low temperature drift.


For all the output waveform, the output waveform is symmetrical for the reference waveform, in the case of low output impedance, output current up to ± 20 mA current.


In the two and TTL / CMOS signal input match the address pins A1, A0, enter the appropriate code signal, to achieve control of the output waveform transformation, the specific input codes and output waveforms of the corresponding relationship shown in Table 1.


When V + = 5 V, V-=- 5 V, VDADJ = VFADJ = VPDI = VPDO = 0 V, RL = 1 k , CL = 20 pF, the output waveform, frequency adjustment, the output voltage can reach Vp-stable p = 2 V.


1.2 PGA202/203 chip features


PGA 202/203 for the program-controlled voltage amplifier. PGA202 decimal zoom mode, amplification factor for the 1,10,100,1 000. PGA203 binary zoom mode, amplification factor for the 1,2,4,8, the two chips are all TTL / CMOS compatible. PGA202 chip pin diagram shown in Figure 2.