Description The MAX038 is a high-frequency, precision function generator producing accurate, high-frequency triangle, sawtooth, sine, square, and pulse waveforms with a minimum of external components. The output frequency can be controlled over a frequency range of 0.1Hz to 20MHz by an internal 2.5V bandgap voltage reference and an external resistor and capacitor. The duty cycle can be varied over a wide range by applying a ±2.3V control signal, facilitating pulse-width modulation and the generation of sawtooth waveforms. Frequency modulation and frequency sweeping are achieved in the same way. The duty cycle and frequency controls are independent.

Sine, square, or triangle waveforms can be selected at the output by setting the appropriate code at two TTL-compatible select pins. The output signal for all waveforms is a 2VP-P signal that is symmetrical around ground. The low-impedance output can drive up to ±20mA.

The TTL-compatible SYNC output from the internal oscillator maintains a 50% duty cycle—regardless of the duty cycle of the other waveforms—to synchronize other devices in the system. The internal oscillator can be synchronized to an external TTL clock connected to PDI.

Key Features

• 0.1Hz to 20MHz Operating Frequency Range
• Triangle, Sawtooth, Sine, Square, and Pulse Waveforms
• Independent Frequency and Duty-Cycle Adjustments
• 350 to 1 Frequency Sweep Range
• 15% to 85% Variable Duty Cycle
• Low-Impedance Output Buffer: 0.1Ω
• Low 200ppm/°C Temperature Drift

Applications/Uses

• Frequency Modulators
• Frequency Synthesizer
• FSK Generator—Sine and Square Waves
• Phase-Locked Loops (PLLs)
• Precision Function Generators
• Pulse-Width Modulators
• Voltage-Controlled Oscillators