ISL1902

3

FN7981.2

March 20, 2013

17

LREF

The non-inverting input to the uncommitted linear amplifier.

18

LOUT

Output of the uncommitted linear amplifier.

19

OVP

Input to detect an overvoltage (OV) condition on the output with a nominal threshold of 1.5V. Since the control variable is output

current, a fault that results in an open circuit will cause excessive output voltage. The circuit hysteresis is a switched current source

that is active when the OV threshold is exceeded.

20

AC

Input to sense AC voltage presence and amplitude. A resistor divider from line and neutral/line and circuit ground is used to detect

the AC voltage.

21

GND

Signal and power ground connections for this device. Due to high peak currents and high frequency operation, a low impedance

layout is necessary. Ground planes and short traces are highly recommended.

22

INRUSH Output to drive an isolation transformer to control an inrush current limiting device. Typically this would be a triac, back-to-back FETs,

or anti-parallel SCRs, etc. The output is a 50% duty cycle ~80kHz square-wave capable of sourcing 10mA. The output is enabled in

conjunction with an AC outage (such as from a wall dimmer). Operation is delayed for ~150µs after AC returns and is enabled until

AC is interrupted again. The INRUSH output is also inhibited during normal AC zero-crossing even at full conduction angle.

23

capability when UVLO is active or when the IC is not biased. This output is used to drive the dimming FET in series with the LED string.

The PWM operates at ~310Hz.

24

OUT

PIN # SYMBOL

DESCRIPTION

Ordering Information

PART NUMBER

(Notes 1, 2, 3)

PART

MARKING

TEMP. RANGE

(°C)

PACKAGE

(Pb-free)

PKG. DWG.

#

ISL1902FAZ

ISL 1902FAZ

-40 to +125

24 Ld QSOP

M24.15

NOTES:

1. Add “-T*” suffix for tape and reel. Please refer to TB347 for details on reel specifications.

2. These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and 100% matte

tin plate plus anneal (e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Intersil

Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.

3. For Moisture Sensitivity Level (MSL), please see device information page for ISL1902. For more information on MSL please see tech brief TB363.