CURRENT MODE PWM CONTROLLER

AZ3842/3/4/5

Advanced Analog Circuits

Data Sheet

7

March 2003

Rev: 1.0

Electrical Characteristics (Continued)

Figure 4 is the basic test circuit for AZ384x. In testing, the high peak currents associated with capacitive loads necessitate

careful grounding techniques. Timing and bypass capacitors should be connected close to pin 5 in a single point ground. The

transistor and 5k potentiometer are used to sample the oscillator waveform and apply an adjustable ramp to pin 3.

Figure 7. Reference Voltage vs. Ambient Temperature

Figure 8. Start-up Current vs. Ambient Temperature

Typical Performance Characteristics

Figure 5. Oscillator Dead Time vs. Timing Capacitor

Figure 6. Timing Resistor vs. Frequency

-40

-20

0

20406080

100

120

0.4

0.5

0.6

0.7

0.8

0.9

1.0

AZ3842

Ambient Temperature (

110

100

1

10

0.3

30

3

47

22

4.7

2.2

Timing Capacitor (nF)

100

1k

10k

100k

1M

10k

100k

5K

50K

Frequency (Hz)

-40

-20

0

20

40

60

80

100

120

4.980

4.985

4.990

4.995

5.000

5.005

5.010

5.015

V

Ambient Temperature (