LC7573N データシートの表示（PDF） - SANYO -> Panasonic

部品番号

コンポーネント説明

メーカー

LC7573N

1/2 Duty VFD Driver for Frequency Display

SANYO -> Panasonic 

LC7573N, 7573NM

Relation between Segment and Digit Outputs

Figure 4

Descriptions

1. Consider the examples shown in Figure 4, where data is set up so that the segment outputs S1 to S19 output a low

level on the G1 digit output timing and a high level on the G2 digit output timing. (Here, the G2 side being lighted)

2. The digit output G1 and G2 waveforms in Example 1 are output when the 10 bits of dimmer data (DM0 to DM9) are

set to 3FEH. The relation between t1 and the oscillator frequency fOSC is:

t1 = 2/fOSC.

For example, if fOSC = 1.6 [MHz], then

t1 = 2/1.6 [MHz] = 1.25 [µs].

Note that t1 and t2 are the same period in Example 1.

3. The digit output G1 and G2 waveforms in Example 2 are those when the dimmer data (DM0 to DM9) are set to a

smaller value. Although the time t1, which is from the point where digit output falls to segment output changes, does

not change, the time t2, which is from the point where segment output changes to the time the digit output rises,

becomes longer. When the dimmer data (DM0 to DM9) are set to 0FFH and fOSC is 1.6 [MHz], then the frame

frequency fO is:

fO = 1/(t3 × 2)

= fOSC/4096

= 391 [Hz],

and,

t3 = 1.28 [ms].

Therefore,

t2 =

(1.28 [ms] – 1.25 [µs] × 2) × (3FFH – 0FFH)

1023

= 0.96 [ms].

4. When the dimmer data (DM0 to DM9) are set to an even smaller value, the time t2, which is from the point where

segment output changes to the time the digit output rises, becomes even longer, as in Example 3. Note that t1 does

not change here, either.

No. 3587-8/10

Share Link: