Notes :

2. These parameters, although guaranteed, are not 100% tested in production.

4. Gain defined as :

A=

; 0

6. Output frequency equals oscillator frequency for the UC3842 and UC3843.

Output frequency is one half oscillator frequency for the UC3844 and UC3845.

ELECTRICAL CHARACTERISTICS (continued)

Symbo l

Parameter

T est Cond ition s

UC284X

UC384X

Unit

Min. T yp. Max. Min. T yp. Max.

UNDER-VOLTAGE LOCKOUT SECTION

Start Threshold

X842/4

15

16

17

14.5

16

17.5

V

X843/5

7.8

8.4

9.0

7.8

8.4

9

V

Min Operating Voltage

After Turn-on

X842/4

9

10

11

8.5

10

11.5

V

X843/5

7.0

7.6

8.2

7.0

7.6

8.2

V

PWM SECTION

Maximum Duty Cycle

X842/3

93

97

100

93

97

100

%

X844/5

46

48

50

47

48

50

%

Minimum Duty Cycle

0

0

%

TOTAL STANDBY CURRENT

Start-up Current

0.5

1

0.5

1

mA

Operating Supply Current

11

20

11

20

mA

Zener Voltage

34

34

V

UC2842/3/4/5-UC3842/3/4/5

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