HA16114P 参数 Datasheet PDF下载

HA16114P/PJ/FP/FPJ, HA16120FP/FPJ

The oscillator frequency f

OSC

can be calculated as follows.

f

OSC

=

Here, t

1

=

t2 =

1

t

1

+ t

2

+ t

3

C

T

×

(V

H

−

V

L

)

1.1 V/R

T

C

T

×

(V

H

−

V

L

)

3

×

1.1 V/R

T

t3

≈

0.8

µs

(comparator delay time)

Since V

H

−

V

L

= 0.6 V

f

OSC

≈

1

(Hz)

0.73

×

C

T

×

R

T

+ 0.8 (µs)

At high frequencies the comparator delay causes the sawtooth wave to overshoot the 1.6 V threshold and

undershoot the 1.0 V threshold, and changes the dead-band thresholds accordingly. Select constants by

testing under implementation conditions.

3.2 V

(Internal voltage)

Current

mirror

C

T

charging

I

O

Oscillator

comparator

1.1 V

1:4

Discharg

-ing 3I

O

R

C

R

B

Sync

circuit

R

T

C

T

I

O

External circuit

V

H

= 1.6 V typ

Vref

2.5 V

R

A

SYNC

t

2

t

1

V

L

= 1.0 V typ

t

1

: t

2

= 3 : 1

Figure 1.1 Equivalent Circuit of Oscillator

Rev.2.0, Sep.18.2003, page 7 of 37