Boost Converter Topology

20117310

Magnetic Boost DC/DC Converter Electrical Characteristics

Symbol

Parameter

Conditions

Min

Typ

Max

Units

I

LOAD

Load Current

3.0V

≤ V

IN

≤ 4.5V

V

0

300

mA

V

FB

Voltage Accuracy at FB Pin

(Boost Converter Output

Voltage Accuracy)

1mA

≤ I

SW

≤ 300 mA

3.0V

≤ V

IN

≤ V (FB) – 0.5

V(FB)=5V

−5

+5

%

Voltage at FB Pin

(Boost Converter Output

Voltage)

1mA

≤ I

SW

≤ 300 mA

V

(SCHOTTKY)

5V

1mA

≤ I

SW

≤ 300 mA

V

V

V

RDS

ON

Switch ON Resistance

V

0.5A

0.4

0.7

Ω

f

PWF

PWM Mode Switching

Frequency

RT=82k

Ω

1

MHz

Frequency Accuracy

2.65

≤ V

DD1,2

≤ 2.9

−6

%

RT=82k

Ω

−9

+9

t

STARTUP

Startup Time

From NSTBY and

EN_BOOST

25

ms

I

CL_OUT

SW Pin Current Limit

670

800

915

mA

530

995

Boost Standby Mode

User can set the Boost Converter to STANDBY mode by writing the register bit EN_BOOST low. When EN_BOOST is written

high, the converter waits for 10 ms for the internal voltages and currents to stabilize and then starts for 10 ms in PFM mode and

then goes to PWM mode.

www.national.com

9