Buzzer Output Circuit; Configuration Of Buzzer Output Circuit; Mask Option - Epson S1C63358 Technical Manual

4.13 Buzzer Output Circuit

4.13.1 Configuration of buzzer output circuit

The S1C63358 is capable of generating buzzer signal to drive a piezo-electric buzzer. The buzzer signal is
output from the BZ terminal by software control. Furthermore, the buzzer signal frequency can be set to 2
kHz or 4 kHz with 2 Hz interval by software.
Figure 4.13.1.1 shows the configuration of the buzzer output circuit.

4.13.2 Mask option

Polarity of the buzzer signal output from the BZ terminal can be selected as either positive polarity or
negative polarity. Figure 4.13.2.1 shows each output circuit configuration and the output waveform.
When positive polarity is selected, the BZ terminal goes to a low (V
output. Select positive polarity when driving a piezo buzzer by externally connecting an NPN transistor.
When negative polarity is selected, the BZ terminal goes to a high (V
output. Select negative polarity when driving a piezo buzzer by externally connecting a PNP transistor.
Buzzer signal
S1C63358 TECHNICAL MANUAL
CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (Buzzer Output Circuit)
2 kHz
f
Divider
OSC1
4 kHz
Fig. 4.13.1.1 Configuration of buzzer output circuit
Buzzer signal
(a) When positive polarity is selected
(b) When negative polarity is selected
Fig. 4.13.2.1 Configuration of output circuit
ENON
Buzzer output
Selector
control circuit
BZFQ BZON
) level when the buzzer signal is not
SS
) level when the buzzer signal is not
DD
Piezo
V
DD
BZ
V
SS
V
DD
BZ
V
SS
Piezo
EPSON
BZ
V
DD
V
SS
V
DD
V
SS
101