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LCX009AK

Level Conversion Circuit

The LCX009AK has a built-in level conversion circuit in the clock input unit located inside the panel. The circuit

voltage is stepped up to 13.5V. This level conversion circuit meets the specifications of a 3.0V to 5.0V power

supply of the externally-driven IC mainly. However, this circuit can operate even with a 12V power supply of

the IC.

1. I/O characteristics of level conversion circuit

(For a single-phase input unit)

An example of the I/O voltage characteristics of a

level conversion circuit is shown in the figure to the

right. The input voltage value that becomes half the

output voltage (after voltage conversion) is defined

as Vth.

The Vth values under standard conditions are

indicated in the table below. (HST, VST, EN, CLR, and RGT in the case of a single-phase input)

2

Vth

Input voltage [V]

Example of single-phase

I/O characteristics

Item

Vth voltage of circuit

Vth

0.35

1.50

2.70

V

Symbol

Min.

Typ.

Max.

Unit

(For a differential input unit)

An example of I/O voltage characteristics of a

level conversion circuit for a differential input is

shown in the figure to the right. Although the

characteristics, including those of the Vth voltage,

are basically the same as those for a single-

phased input, the two-phased input phase is

defined. (Refer to clock timing conditions.)

2

Vth

Input voltage [V]

Example of differential

I/O characteristics

2. Current characteristics at the input pin of level

conversion circuit

A slight pull-in current is generated at the input

pin of the level conversion circuit. (The equivalent

circuit diagram is shown to the right.) The current

volume increases as the voltage at the input pin

decreases, and is maximized when the pin is

grounded.) (Electrical characteristics are defined

by the grounded input.)

Output

HCK1

input

HCK2

input

Level conversion equivalent circuit

0

0

Max. value

Input pin voltage [V]

10

Pull-in current

characteristics at the

input pin