HA16163T

Rev.5.0, Mar.15.2004, page 13 of 29

Oscillator

The oscillation frequency of the oscillator is set by means of a resistance connected between the RT pin and GND. The

following graph shows the relationship between the external resistance and the oscillation frequency. The typical value

of the oscillation frequency is given by the following equation.

fosc =

[Hz]

1

30p[F]

× RT[Ω] + 50[ns]

10000

10

10

1000

100

RT (k

Ω)

fosc vs. RT

100

1000

RT

SYNC

RT

(2.7V)

GND

HA16163

SYNC pin: open

Figure 6

Place the resistor for connection to the RT pin as close to the pin as is possible. Please design the pattern so that the

level of cross-talk from other signals is minimized.

Synchronized Operation

Parallel synchronized operation is possible by connecting the SYNC pins of HA16163s. In this case, up to four slave

ICs can be connected to one master IC. A value of at least twice the master RT value should be set for the slave IC RT

values.

RT

RT

SYNC

SYNC

RT

2*RT

(2.7V)

(2.7V)

GND

GND

HA16163

HA16163

RT

SYNC

2*RT

Max. 4 slaves

(2.7V)

GND

MASTER

SLAVE

SLAVE

HA16163

Figure 7 Parallel Synchronized Operation