TPS65251

SLVSAA4B – JUNE 2010 – REVISED JANUARY 2011

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PACKAGE DISSIPATION RATINGS

(1)

PACKAGE

POWER RATING (W)

POWER RATING (W)

POWER RATING (W)

RHA

30

3.33

2.3

1.3

(1)

Based on JEDEC 51.5 HIGH K environment measured on a 76.2 x 114 x .6-mm board with the following layer arrangement:

(a) Top layer: 2 Oz Cu, 6.7% coverage

(b) Layer 2: 1 Oz Cu, 90% coverage

(c) Layer 3: 1 Oz Cu, 90% coverage

(d) Bottom layer: 2 Oz Cu, 20% coverage

ELECTRICAL CHARACTERISTICS

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNIT

INPUT SUPPLY UVLO AND INTERNAL SUPPLY VOLTAGE

Input Voltage range

4.5

18

V

Shutdown

EN pin = low for all converters

1.3

mA

Converters enabled, no load

Quiescent, low power disabled (Lo)

Buck 1 = 3.3 V, Buck 2 = 2.5 V,

20

mA

Buck 3 = 7.5 V

Converters enabled, no load

Quiescent, low power enabled (Hi)

Buck 1 = 3.3 V, Buck 2 = 2.5 V,

1.5

mA

Buck 3 = 7.5 V

4.22

V

4.1

Both edges

110

µs

V3V

Internal biasing supply

3.3

V

V7V

Internal biasing supply

6.25

V

Rising V7V

3.8

UVLO for internal V7V rail

V

Falling V7V

3.6

Falling edge

110

µs

BUCK CONVERTERS (ENABLE CIRCUIT, CURRENT LIMIT, SOFT START, SWITCHING FREQUENCY AND SYNC CIRCUIT, LOW

POWER MODE)

VIH

Enable threshold high

V3p3 = 3.2 V - 3.4 V

1.55

V

VIL

Enable treshold Low

V3p3 = 3.2 V - 3.4 V

1.24

V

Pull up current enable pin

1.1

µA

Discharge time enable pins

Power-up

10

ms

Soft start pin current source

5

µA

Converter switching frequency range

Set externally with resistor

0.3

2.2

MHz

Frequency setting resistor

Depending on set frequency

50

600

k

Ω

Internal oscillator accuracy

-10

10

%

External clock threshold high

V3p3 = 3.3 V

1.55

V

External clock treshold Low

V3p3 = 3.3 V

1.24

V

Synchronization range

0.2

2.2

MHz

Sync signal minimum duty cycle

40

%

Sync signal maximum duty cycle

60

%

Low power mode threshold high

V3p3 = 3.3 V

1.55

V

Low power mode treshold Low

V3p3 = 3.3 V

1.24

V

FEEDBACK, REGULATION, OUTPUT STAGE

-1%

0.8

1%

Feedback voltage

V

-2%

0.8

2%

Minimum on time

80

120

ns

(current sense blanking)

6

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