High-Efficiency, 26V Step-Up Converters

for Two to Six White LEDs

_______________________________________________________________________________________

3

ELECTRICAL CHARACTERISTICS (continued)

Note 2: Time from CTRL going below the dual-mode threshold to IC shutdown.

Note 3: Specifications to -40°C are guaranteed by design and not production tested.

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

N-CHANNEL SWITCH

LX On-Resistance

1.45

2.25

Ω

°C

0.01

5

LX Leakage Current

°C1

µA

LX Current Limit

Duty cycle = 90%

450

700

950

mA

ELECTRICAL CHARACTERISTICS

wise noted.) (Note 3)

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Supply Voltage

2.6

5.5

V

UVLO Threshold

2.10

2.55

V

Quiescent Current

No switching

0.55

mA

OVLO Threshold

26

29

V

10

30

OUT Input Bias Current

1

µA

Output Voltage Range

(Note 1)

25.5

V

ERROR AMPLIFIER

CTRL to CS Regulation

0.093

0.107

V

CTRL Input Resistance

≤ 1.0V

240

780

k

Ω

CTRL Dual-Mode Threshold

100

240

mV

MAX1561

6

11

CTRL Shutdown Enable Delay

(Note 2)

MAX1599

13

22

ms

CS-to-COMP Transconductance

32

85

µS

OSCILLATOR

MAX1561

0.75

1.25

Operating Frequency

MAX1599

0.37

0.63

MHz

Maximum Duty Cycle

CTRL = IN, CS = GND

91

%

N-CHANNEL SWITCH

LX On-Resistance

2.25

Ω

LX Current Limit

Duty cycle = 90%

450

950

mA