MC3405

6

MOTOROLA ANALOG IC DEVICE DATA

Slope Can Be Either Polarity.

VCC = +15 V

VEE = Gnd

COMPARATOR SECTION

Figure 7. Normalized Input Offset Voltage

Figure 8. Input Bias Current

Figure 9. Normalized Input Offset Current

Figure 10. Output Sink Current versus

Output Voltage

Figure 11. Pulse Width Modulator Schematic and Waveforms

TA, AMBIENT TEMPERATURE (°C)

1.40

1.20

1.00

0.80

0.60

0.40

–60

–40

–20

0

20

40

60

80

100

120

140

Slope Can Be Either Polarity.

VCC = +15 V

VEE = Gnd

VCC, POSITIVE SUPPLY VOLTAGE (V)

200

160

120

80

40

2.0

6.0

10

14

18

22

26

30

VEE = Gnd

TA = +125°C

TA = –55°C

TA = +25°C

TA, AMBIENT TEMPERATURE (°C)

2.20

1.80

1.40

1.00

0.60

0.20

–60

–40

–20

0

20

40

60

80

100

120

140

VOL, OUTPUT VOLTAGE (mV)

7.0

6.0

5.0

4.0

3.0

2.0

1.0

0

0

200

400

600

800

1000

TA = +125°C

TA = +25°C

TA = –55°C

VCC = +15 V

VEE = Gnd

(a) Oscillator Square Wave Output

VSW

VCC

VEE

Time

(b) Triangle Wave and Control Voltage

(c) Output Pulses

vt

VTH

VTL

Vout

VCC

VEE

Time

Time

Pulse Width =

when: VTL < VC < VTH

Duty Cycle in % =

(100)

Vc – VTL

Vc – VTL

1

f

–

Rf

1

5.0 k

6

5

11

Comp 2

VEE

VCC

4

7

Vout

10

9

C

8

vt

300 k

150 k

R2

R1

12

13

14

VCC

10 k

1.0 M

2

3

VC

+

+

+

+

–

–

–

5.0 k

5.0 k

VEE

R1

4RfCR2

VTH =

VS(1 + R2/R1) + VEE

Oscillator Frequency

f =

VS = VCC – VEE

1

2

VTL =

VS(1 – R2/R1) + VEE

1

2

5.0 k

VSW

VC

Comp 1

Amp 2

Amp 1

VTH –VTL

VTH –VTL