LM2662, LM2663

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SNVS002D – JANUARY 1999 – REVISED MAY 2013

Pin Descriptions

Pin

Name

Function

Voltage Inverter

Voltage Doubler

1

FC

Frequency control for internal oscillator:

Same as inverter.

(LM2662)

FC has no effect when OSC pin is driven externally.

1

SD

Shutdown control pin, tie this pin to the ground in normal

Same as inverter.

(LM2663)

operation.

2

CAP+

Connect this pin to the positive terminal of charge-pump

Same as inverter.

capacitor.

3

GND

Power supply ground input.

Power supply positive voltage input.

4

CAP

−

Connect this pin to the negative terminal of charge-pump

Same as inverter.

capacitor.

5

OUT

Negative voltage output.

Power supply ground input.

6

LV

Low-voltage operation input. Tie LV to GND when input

LV must be tied to OUT.

voltage is less than 3.5V. Above 3.5V, LV can be

connected to GND or left open. When driving OSC with

an external clock, LV must be connected to GND.

7

OSC

Oscillator control input. OSC is connected to an internal

Same as inverter except that OSC cannot be driven by

15 pF capacitor. An external capacitor can be connected

an external clock.

to slow the oscillator. Also, an external clock can be used

to drive OSC.

8

V+

Power supply positive voltage input.

Positive voltage output.

Circuit Description

The LM2662/LM2663 contains four large CMOS switches which are switched in a sequence to invert the input

supply voltage. Energy transfer and storage are provided by external capacitors. Figure 18 illustrates the voltage

switches, and no ESR in the capacitors. In reality, the charge transfer efficiency depends on the switching

frequency, the on-resistance of the switches, and the ESR of the capacitors.

Figure 18. Voltage Inverting Principle

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