TPS54873

SLVS444 – OCTOBER 2002

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3

ELECTRICAL CHARACTERISTICS

TJ = –40

°C to 125°C, VI = 3 V to 6 V (unless otherwise noted)

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNIT

SUPPLY VOLTAGE, VIN

Input voltage range, VIN

4.0

6.0

V

fs = 350 kHz, SYNC ≤ 0.8 V, RT open,

PH pin open

11

15.8

I(Q)

Quiescent current

fs = 550 kHz, SYNC ≥ 2.5 V, RT open,

PH pin open

16

23.5

mA

Shutdown, SS/ENA = 0 V

1

1.4

UNDER VOLTAGE LOCK OUT

Start threshold voltage, UVLO

3.8

3.85

V

Stop threshold voltage, UVLO

3.40

3.50

V

Hysteresis voltage, UVLO

0.14

0.16

V

Rising and falling edge deglitch, UVLO(1)

2.5

µs

BIAS VOLTAGE

Output voltage, VBIAS

I(VBIAS) = 0

2.70

2.80

2.90

V

Output current, VBIAS (2)

100

µA

CUMULATIVE REFERENCE

Vref

Accuracy

0.882

0.891

0.900

V

REGULATION

Lineregulation(1)(3)

IL = 3 A, fs = 350 kHz, TJ = 85°C

0.04

%/V

Lineregulation(1)(3)

IL = 3 A, fs = 550 kHz, TJ = 85°C

0.04

%/V

Loadregulation(1)(3)

IL = 0 A to 6 A, fs = 350 kHz, TJ = 85°C

0.03

%/A

Loadregulation(1)(3)

IL = 0 A to 6 A, fs = 550 kHz, TJ = 85°C

0.03

%/A

OSCILLATOR

Internally set

free running frequency

SYNC

≤ 0.8 V,

RT open

280

350

420

kHz

Internally set—free running frequency

SYNC

≥ 2.5 V,

RT open

440

550

660

kHz

RT = 180 k

Ω (1% resistor to AGND)

252

280

308

Externally set—free running frequency range

RT = 100 k

Ω (1% resistor to AGND)

460

500

540

kHz

Externally set

free running frequency range

RT = 68 k

Ω (1% resistor to AGND)

663

700

762

kHz

High level threshold, SYNC

2.5

V

Low level threshold, SYNC

0.8

V

Pulse duration, external synchronization, SYNC(1)

50

ns

Frequency range, SYNC(1)

330

700

kHz

Ramp valley(1)

0.75

V

Ramp amplitude (peak-to-peak)(1)

1

V

Minimum controllable on time(1)

200

ns

Maximum duty cycle

90%

(1) Specified by design

(2) Static resistive loads only

(3) Specified by the circuit used in Figure 9