MAX660 Monolithic Charge-Pump Voltage Inverter

Overview

The MAX660 is a monolithic, charge-pump voltage inverter designed to provide efficient voltage conversion with minimal external components. It is capable of inverting or doubling an input supply voltage, making it a versatile solution for a wide range of applications. The device operates with input voltages ranging from 1.5V to 5.5V and features low power consumption, high conversion efficiency, and a compact design.

The MAX660 is an upgrade to the ICL7660, offering improved performance and compatibility. Its small footprint and ability to operate with minimal external capacitors make it ideal for space-constrained applications.

Features

• Small capacitors required (1µF to 150µF)
• Low voltage loss: 0.65V typical at 100mA load
• Low operating current: 120µA typical
• Low output impedance: 6.5Ω typical
• Guaranteed output impedance < 15Ω for C1 = C2 = 10µF
• Pin-compatible high-current upgrade for ICL7660
• Inverts or doubles input supply voltage
• Selectable oscillator frequency: 10kHz or 80kHz
• High conversion efficiency: 88% typical at 100mA load

Applications

The MAX660 is suitable for a variety of applications, including:

• Portable and battery-powered devices
• Negative voltage generation for analog circuits
• Voltage doubling for low-voltage systems
• Power supply inversion in mixed-signal designs
• Data acquisition systems
• Industrial and medical instrumentation

Electrical Characteristics

Absolute Maximum Ratings

• Supply Voltage (V+): 6V
• Voltage at CAP-, OUT, CAP+: -0.3V to (V+ + 0.3V)
• Operating Temperature Range:
  • Commercial (C): 0°C to +70°C
  • Extended (E): -40°C to +85°C
• Storage Temperature Range: -65°C to +150°C

Typical Performance Characteristics

• Input Voltage Range: 1.5V to 5.5V
• Output Voltage Range: -VIN to +2VIN
• Output Current: Up to 100mA
• Conversion Efficiency: 88% typical at 100mA load
• Oscillator Frequency: Selectable between 10kHz and 80kHz

Package Information

Pin Configuration

The MAX660 is available in 8-pin DIP and SO packages. The pinout is as follows:

• Pin 1: FC (Frequency Control)
• Pin 2: CAP+ (Positive Capacitor Terminal)
• Pin 3: GND (Ground)
• Pin 4: CAP- (Negative Capacitor Terminal)
• Pin 5: V+ (Supply Voltage)
• Pin 6: OSC (Oscillator Control)
• Pin 7: LV (Low Voltage Indicator)
• Pin 8: OUT (Output Voltage)

Ordering Information

• MAX660CPA: 0°C to +70°C, 8-pin Plastic DIP
• MAX660CSA: 0°C to +70°C, 8-pin SO
• MAX660C/D: 0°C to +70°C, Dice*
• MAX660EPA: -40°C to +85°C, 8-pin Plastic DIP
• MAX660ESA: -40°C to +85°C, 8-pin SO

*Contact factory for dice specifications.

Typical Operating Circuits

Voltage Inverter Configuration

To invert the input voltage, connect the MAX660 as follows:

• Connect V+ to the positive supply voltage (1.5V to 5.5V).
• Connect GND to the system ground.
• Connect CAP+ and CAP- to external capacitors (1µF to 150µF).
• The output at OUT will be -VIN.

Voltage Doubler Configuration

To double the input voltage, connect the MAX660 as follows:

• Connect V+ to the positive supply voltage (2.5V to 5.5V).
• Connect GND to the system ground.
• Connect CAP+ and CAP- to external capacitors (1µF to 150µF).
• The output at OUT will be +2VIN.

Conclusion

The MAX660 is a highly efficient and versatile charge-pump voltage inverter and doubler, offering excellent performance with minimal external components. Its low power consumption, high conversion efficiency, and compact design make it an ideal choice for a wide range of applications, from portable devices to industrial systems. With its pin compatibility with the ICL7660 and improved specifications, the MAX660 provides a reliable upgrade for existing designs.