Off-Line and DC-DC PWM Controllers for

High-Brightness LED Drivers

_______________________________________________________________________________________

3

Note 3: The MAX16801 is intended for use in universal input off-line drivers. The internal clamp circuit is used to prevent the boot-

strap capacitor (C1 in Figure 5) from charging to a voltage beyond the absolute maximum rating of the device when

EN/UVLO is low. The maximum current to IN (hence to clamp) when UVLO is low (device in shutdown), must be externally

limited to 2mA (max). Clamp currents higher than 2mA may result in clamp voltage higher than +30V, thus exceeding the

absolute maximum rating for IN. For the MAX16802, do not exceed the +24V maximum operating voltage of the device.

ELECTRICAL CHARACTERISTICS (continued)

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

CURRENT-SENSE COMPARATOR

Current-Sense Trip Threshold

262

291

320

mV

CS Input Bias Current

-2

+2

µA

Propagation Delay From

Comparator Input to NDRV

50mV overdrive

60

ns

Switching Frequency

230

262

290

kHz

MAX1680_A

50

50.5

Maximum Duty Cycle

MAX1680_B

75

76

%

IN CLAMP VOLTAGE

IN Clamp Voltage

2mA sink current, MAX16801 only (Note 3)

24.1

26.1

29.0

V

ERROR AMPLIFIER

Voltage Gain

Ω

80

dB

Unity Gain Bandwidth

2

MHz

Phase Margin

65

degrees

DIM/FB Input Offset Voltage

3mV

High

2.2

3.5

COMP Pin Clamp Voltage

Low

0.4

1.1

V

Source Current

0.5

mA

Sink Current

0.5

mA

Reference Voltage

(Note 2)

1.218

1.230

1.242

V

Input Bias Current

50

nA

COMP Short-Circuit Current

8mA

THERMAL SHUTDOWN

Thermal-Shutdown Temperature

130

°C

Thermal Hysteresis

25

°C

DIGITAL SOFT-START

Soft-Start Duration

15,872

clock

cycles

Reference Voltage Steps During

Soft-Start

31

steps

Reference Voltage Step

40

mV