3

TC2575

TC2575-1 3/13/00

1.0A Step-Down Switching Regulator

ing junction temperature range that applies (Note 2), unless otherwise noted.

Symbol

Parameter

Test Conditions

Min

Typ

Max

Units

TC2575-ALL OUTPUT VOLTAGE VERSIONS

Feedback Bias Current

nA

—

25

100

—

—

200

Oscillator Frequency (Note 3)

—

52

—

kHz

—

58

—

63

Saturation Voltage

V

—

1.0

1.2

—

—

1.3

DC

Max Duty Cycle (“on”) [Note 5]

94

98

—

%

Current Limit Peak Current

A

(Notes 3 and 4)

1.7

2.3

3.0

1.4

—

3.2

Output Leakage Current

mA

Output = 0 V

—

0.8

2.0

Output = – 1.0 V

—

6.0

20

Quiescent Current (Note 6)

mA

—

5.0

9.0

—

11

Standby Quiescent Current,

µA

ON/OFF Pin = 5.0 V (“off”)

—

80

200

—

—

400

ON/OFF Pin Logic Input Level

V

(Test Figure 2)

2.2

1.4

—

2.4

—

—

Nominal Output Voltage

V

—

1.2

1.0

—

—

0.8

ON/OFF Pin Input Current

µA

(Test Figure 2)

ON/OFF Pin = 5.0V (“off”),

—

15

30

ON/OFF Pin Input Current

ON/OFF Pin = 0V (“on”),

—

0

5.0

µA

NOTES: 3. The oscillator frequency reduces to approximately 18kHz in the event of an output short or an overload which causes the regulated

output voltage to drop approximately 40% from the nominal output voltage. This self protection feature lowers the average power

dissipation of the IC by lowering the minimum duty cycle from 5% down to approximately 2%.

4. Output (Pin 2) sourcing current. No diode, inductor or capacitor connected to the output pin.

5. Feedback (Pin 4) removed from output and connected to 0V.

6. Feedback (Pin 4) removed from output and connected to +12V for the Adjustable, 3.3V, and 5.0V versions, and 25V for the 12V,

to force the output transistor "OFF".