Overview
The LM2662MX from Texas Instruments is a switched capacitor voltage converter designed to invert or double input supply voltages. This CMOS charge-pump converter is ideal for battery-powered systems due to its low operating current and high efficiency. It can convert a positive input voltage in the range of 1.5 V to 5.5 V to the corresponding negative voltage or double the input voltage. The device uses two external capacitors to achieve this conversion, eliminating the need for inductors and thus reducing cost, size, and electromagnetic interference (EMI).
Key Specifications
| Parameter | Minimum | Typical | Maximum | Unit |
|---|---|---|---|---|
| Supply Voltage (V+ to GND) | 1.5 | - | 5.5 | V |
| Output Current | - | - | 200 | mA |
| Output Resistance | - | 3.5 | 7 | Ω |
| Oscillator Frequency (LM2662) | 20 | - | 150 | kHz |
| Oscillator Frequency (LM2663) | - | 150 | - | kHz |
| Supply Current (No Load, LM2662) | 0.3 | 1.3 | 4 | mA |
| Shutdown Supply Current (LM2663) | - | 10 | - | μA |
| Operating Ambient Temperature | -40 | - | 85 | °C |
| Operating Junction Temperature | -40 | - | 105 | °C |
Key Features
- Inverts or doubles input supply voltage in the range of 1.5 V to 5.5 V.
- Uses two low-cost external capacitors for energy transfer and storage, eliminating the need for inductors.
- High efficiency with typical conversion efficiency of 86% at 200 mA load.
- Low operating current of 300 μA and shutdown current of 10 μA for LM2663.
- Selectable oscillator frequency for LM2662: 20 kHz or 150 kHz, and fixed 150 kHz for LM2663.
- External clock capability for driving the oscillator in inverter mode.
- Low-voltage operation input (LV) to optimize performance for input voltages less than 3.5 V.
Applications
- Battery-powered systems such as laptop computers, cellular phones, and handheld instruments.
- Medical instruments and operational amplifier power supplies.
- Interface power supplies and other applications requiring negative or doubled voltage.
- Precision voltage dividers and splitting input voltage in half.
Q & A
- What is the primary function of the LM2662MX?
The LM2662MX is a switched capacitor voltage converter that can invert or double the input supply voltage.
- What is the input voltage range for the LM2662MX?
The input voltage range is from 1.5 V to 5.5 V.
- How much output current can the LM2662MX provide?
The device can provide up to 200 mA of output current.
- What are the typical oscillator frequencies for the LM2662 and LM2663?
The LM2662 has selectable oscillator frequencies of 20 kHz or 150 kHz, while the LM2663 operates at a fixed frequency of 150 kHz.
- Can the LM2662MX be driven by an external clock?
Yes, the LM2662 can be driven by an external clock in inverter mode, but not in voltage-doubling mode.
- What is the shutdown current for the LM2663?
The shutdown current for the LM2663 is 10 μA.
- What are some typical applications for the LM2662MX?
Typical applications include battery-powered systems, medical instruments, operational amplifier power supplies, and interface power supplies.
- How does the LM2662MX handle low-voltage input?
For input voltages less than 3.5 V, the LV pin must be connected to ground to optimize performance.
- What is the operating ambient temperature range for the LM2662MX?
The operating ambient temperature range is from -40°C to 85°C.
- What is the typical conversion efficiency of the LM2662MX at 200 mA load?
The typical conversion efficiency is 86% at a 200 mA load.
