NCP1444 Ver la hoja de datos (PDF) - ON Semiconductor

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componentes Descripción

Fabricante

NCP1444

4.0 A 280 kHz/560 kHz Boost Regulators

ON Semiconductor 

NCP1442, NCP1443, NCP1444, NCP1445

ELECTRICAL CHARACTERISTICS (continued) (2.7 V < VCC < 30 V; 0°C < TA < 85°C; 0°C < TJ < 125°C; For all

NCP1442/3/4/5 specifications unless otherwise stated.) (See Note 2)

Characteristic

Test Conditions

Min

Typ

Max

Power Switch

Switch Saturation Voltage

ISWITCH = 4.0 A

ISWITCH = 10 mA, 2.7 V < VCC < 12 V

ISWITCH = 10 mA, 12 V < VCC < 30 V

−

0.6

1.0

−

0.14

0.5

−

0.9

0.4

Switch Current Limit

50% duty cycle (Note 4)

80% duty cycle (Note 4)

5.0

6.0

8.0

4.0

−

−

Minimum Pulse Width

Switch Transconductance, DICC/ DIVSW

FB = 0 V or NFB = 0 V, ISW = 4.0 A (Note 4)

2.7 V ≤ VCC ≤ 12 V, 10 mA ≤ ISW ≤ 4.0 A

12 V < VCC ≤ 30 V, 10 mA ≤ ISW ≤ 4.0 A

200

250

300

−

8.0

30

−

10

50

Switch Leakage

General

VSW = 40 V, VCC = 0V

−

2.0

20

Operating Current

Shutdown Mode Current

ISW = 0

VC < 0.8 V, SS = 0 V, 2.7 V ≤ VCC ≤ 12 V

VC < 0.8 V, SS = 0 V, 12 V ≤ VCC ≤ 30 V

−

15

27

−

16

60

−

25

60

Minimum Operation Input Voltage

Thermal Shutdown

VSW switching, maximum ISW = 10 mA

(Note 4)

−

2.2

2.6

150

180

210

Thermal Hysteresis

(Note 4)

4. Guaranteed by design, not 100% tested in production.

−

25

−

Unit

V

V

V

A

A

ns

mA/A

mA

mA

mA

V

°C

°C

PACKAGE PIN DESCRIPTION

Package Pin Number Pin Symbol

1

VC

2 (NCP1442/4 only)

FB

2 (NCP1443/5 only)

3 (NCP1442/4 only)

3 (NCP1443/5 only)

Test

NFB

4

GND

5

VSW

6

SS

7

VCC

Function

Loop compensation pin. The VC pin is the output of the error amplifier and is used for loop

compensation, current limit and soft start. Loop compensation can be implemented by a sim-

ple RC network as shown in the application diagram on page 2.

Positive regulator feedback pin. This pin senses a positive output voltage and is referenced to

1.276 V. When the voltage at this pin falls below 0.4 V, chip switching frequency reduces to

20% of the nominal frequency.

These pins are connected to internal test logic and should either be left floating or tied to

ground. Connection to a voltage between 2.0 V and 6.0 V shuts down the internal oscillator

and leaves the power switch running.

Negative feedback pin. This pin senses a negative output voltage and is referenced to −2.475

V. When the voltage at this pin goes above −0.65 V, chip switching frequency reduces to 20%

of the nominal frequency.

Ground pin. This pin provides a ground for the controller circuitry and the internal power

switch. This pin is internally connected to the metal pad of the package to provide an addition-

al ground connection as well as an effective means of dissipating heat.

High current switch pin. This pin connects internally to the collector of the power switch. The

open voltage across the power switch can be as high as 40 V. To minimize radiation, use a

trace as short as practical.

Synchronization and shutdown pin. This pin may be used to synchronize the part to nearly

twice the base frequency. A TTL low will shut the part down and put it into low current mode.

If synchronization is not used, this pin should be either tied high or left floating for normal

operation.

Input power supply pin. This pin supplies power to the part and should have a bypass capaci-

tor connected to GND.

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