A

4/99

TOP412/414

11

Conditions

(Unless Otherwise Specified)

Specification

Symbol

See Figure 11

Min

Typ

Max

Units

VS2 = 16 V R1 = 0

Ω

SOURCE = 0 V

T

LOW INPUT VOLTAGE OPERATION (See Note C)

Volts

mA

mA

%

Hz

DRAIN Supply

Voltage

CONTROL Pin

Charging Current

Auto-restart

Duty Cycle

Auto-restart

Frequency

NOTES:

A. For specifications with negative values, a negative temperature coefficient corresponds to an increase in

magnitude with increasing temperature, and a positive temperature coefficient corresponds to a decrease in

magnitude with increasing temperature.

B. It is possible to start up and operate TOPSwitch at DRAIN voltages well below 36 V. Refer to the "Low Input

Voltage" Specification section for details.

C. This section specifies only parameters affected by low input voltage operation (Drain Voltages less than 36 V). All

other parameters remain unchanged.

D. For low input voltage applications, the primary peak current could be set to a lower value than the current limit to

increase efficiency. Refer to the Output Characteristics graph (Drain Current vs. Drain Voltage). The voltage

across the transformer primary during the ON time is the difference between the input voltage and the drain

voltage (V

For example, if the input voltage is 16 VDC and a TOP414 (2.95 A minimum current limit) is used at a primary

peak current of 1A. Then the (V

is 3 V at 100

°C and the energizing voltage across the transformer

primary is 13 V.

S1/Open

S1/Open

See Note D

T

16

-2.30

-1.65

-1.00

-1.20

-0.64

-0.28

48

0.85

V

V