LC7573N, 7573NM
Pin Functions
Pin No.
1
2
5
3
4
7
8
9
6
30, 29
28 to 10
Pin
VFL
VDD
VSS
OSC
BLK
CL
DI
CE
DIM
G1, G2
S1 to S19
I/O
Function
— Driver block power supply. A voltage of between 8.0 and 18.0 V must be supplied.
— Logic block power supply. A voltage of between 4.5 and 5.5 V must be supplied.
— Ground. Must be connected to the system ground.
I/O
Oscillator connection. An oscillator circuit is formed by connecting an external resistor and capacitor
to this pin.
Display off control input
I
BLK = low (VSS): Display off (G1 and G2 = low)
BLK = high (VDD): Display on
Note that serial data can be transferred while the display is turned off.
I
Serial data transfer inputs. These pins must be
connected to the system controller.
CL: synchronization clock
DI: transfer data
CE: chip enable
When the analog dimmer is selected, the analog voltage applied to this pin controls the duty of the G1
and G2 digit output pins. Since a 6-bit A/D converter is applied to this analog voltage and that result is
I input to a decoder that provides a built-in dimmer curve, the relationship between the analog voltage
and the duty can be specified as a mask program. Note that 63/96 · VDD is the full-scale level for the
6-bit A/D converter.
O Digit outputs. The frame frequency fO is (fOSC/4096) Hz
O Segment outputs for displaying the display data transferred by serial data input.
Handling
when unused
—
—
—
VDD
GND
GND
GND
Open
Open
Serial Data Transfer Format
1. When CL is stopped at the low level
2. When CL is stopped at the high level
Figure 2
No. 3587-4/10