STFPC311 datasheet(31/39 Pages) STMICROELECTRONICS

Part #	STFPC311

Description	Front panel controller/driver with standby power management

PDF	39 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

Logo

31 / 39 page

STFPC311

12 Timing characteristics

31/39

Timing characteristics

Table 10.

Timing characteristics ( VDD= 3.3V, TA= -20 to 70°C, unless otherwise noted.

Typical values are at TA= 25°C )

The pulse width of the segment signal is derived from the oscillator frequency. The value can be

modified by trimming ROSC. One cycle of key scanning consists of one frame and data of 12 x

2 matrices are stored in RAM.

Note:

The key scan is only at the end of the frame when the display is ON. When the display is OFF,

the key scan takes place continuously. The grid is turned off during the key scan.

Symbol

Parameter

Test conditions

Values

Unit

Min.

Typ.

Max.

PWCLK

Clock Pulse Width

400

PWSTB

Strobe Pulse Width

tSETUP

Data Setup Time

100

tHOLD

Data Hold Time

100

tCLK-STB Clock-Strobe Time

CLK

STB

tWAIT

Wait Time (1)

Refer to page on Serial Communication Format.

CLK

Figure 27. Key scanning and display timing

STFPC311 Datasheet(PDF) 31 Page - STMicroelectronics