TL1451A
DUAL PULSE WIDTH MODULATION CONTROL CIRCUITS
SLVS024E – FEBRUARY 1983 – REVISED NOVEMBER 1999
TYPICAL CHARACTERISTICS
TRIANGLE OSCILLATOR FREQUENCY
vs
TIMING RESISTANCE
1M
fosc
f osc – Triangle Oscillator Frequency – Hz
afosc
∆
f osc – Oscillator Frequency Variation – %
VCC = 5 V
TA = 25°C
CT = 150 pF
100 k
3
VCC = 3.6 V
RT = 10 kΩ
CT = 330 pF
fosc = 200 kHz
OSCILLATOR FREQUENCY VARIATION
vs
FREE-AIR TEMPERATURE
2
0
CT = 1500 pF
10 k
–1
CT = 15000 pF
1k
1k
–2
4k
10 k
40 k
100 k
400 k
1M
–3
–25
RT – Timing Resistance –
Ω
Figure 3
TRIANGLE WAVEFORM SWING VOLTAGE
vs
TIMING CAPACITANCE
2.6
Triangle Waveform Swing Voltage – V
2.4
2.2
2
1.8
1.6
1.4
1.2
1
0.8
101
10–1
101
VCC = 5 V
RT = 5.1 kΩ
TA = 25°C
Triangle Waveform Period –
µ
s
uS
102
VCC = 5 V
RT = 5.1 kΩ
TA = 25°C
101
100
102
103
104
CT – Timing Capacitance – pF
105
Figure 5
10
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ÎÎÎÎÎ
ÎÎÎÎÎÎÎ Î Î Î Î
Î
ÎÎÎÎÎÎÎ Î Î Î Î
Î
ÎÎÎÎÎÎÎ Î Î Î Î
Î
ÎÎÎÎÎÎÎ Î Î Î Î
Î
ÎÎÎÎÎÎÎ Î Î Î Î
Î
75
0
25
50
TA – Free-Air Temperature –
°C
100
1
Figure 4
TRIANGLE WAVEFORM PERIOD
vs
TIMING CAPACITANCE
102
103
104
CT – Timing Capacitance – pF
105
Figure 6
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