LED Driver. ISL1903 Datasheet


ISL1903 Driver. Datasheet pdf. Equivalent


ISL1903


Dimmable Buck LED Driver - AC Mains or DC Input LED Driver
ISL1903

c1oN-8nO8t8aR-cIEtNCoTOuOEBrRMSTSMOeIcLELhNEonTDricEEwaDPwl RSwRuO.EipnDPptULeoArCrstCTiClE.ceMonEmteN/rtTsact

Dimmable Buck LED Driver - AC Mains or DC Input LED Driver

DATASHEET
FN8285 Rev 1.00 September 20, 2012

The ISL1903 is a high-performance, critical conduction mode (CrCM), single-ended buck LED driver controller. It may be used with DC input converters, but also supports single-stage conversion of the AC mains to a constant current source with power factor correction (PFC). The ISL1903 supports buck converter topologies, such as isolated forward converters or non-isolated source return buck converters. Operation in CrCM allows near zero-voltage switching (ZVS) for improved efficiency while maximizing magnetic core utilization.
The ISL1903 is compatible with both leading and trailing edge modulated AC mains dimmers. It provides all of the features required for high-performance dimmable LED ballast designs.
Applications
• Industrial and commercial LED lighting
• ...



ISL1903
ISL1903
c1oN-8nO8t8aR-cIEtNCoTOuOEBrRMSTSMOeIcLELhNEonTDricEEwaDPwl RSwRuO.EipnDPptULeoArCrstCTiClE.ceMonEmteN/rtTsact
Dimmable Buck LED Driver - AC Mains or DC Input LED Driver
DATASHEET
FN8285
Rev 1.00
September 20, 2012
The ISL1903 is a high-performance, critical conduction mode
(CrCM), single-ended buck LED driver controller. It may be used
with DC input converters, but also supports single-stage
conversion of the AC mains to a constant current source with
power factor correction (PFC). The ISL1903 supports buck
converter topologies, such as isolated forward converters or
non-isolated source return buck converters. Operation in CrCM
allows near zero-voltage switching (ZVS) for improved
efficiency while maximizing magnetic core utilization.
The ISL1903 is compatible with both leading and trailing edge
modulated AC mains dimmers. It provides all of the features
required for high-performance dimmable LED ballast designs.
Applications
• Industrial and commercial LED lighting
• Retrofit LED lamps with triac dimming
• Universal AC mains input LED retrofit lamps
• AC or DC input LED ballasts
Features
• Excellent LED current regulation over line, load, and
temperature
• 0 - 100% dimming with leading-edge (triac) and
trailing-edge dimmers
• Power factor correction for up to 0.995 power factor and
less than 20% harmonic content
• Critical conduction mode (CrCM) operation for
quasi-resonant high efficiency performance
• Supports Universal AC Mains Input
• Configurable for PWM or DC current dimming control of
LEDs
• Monitors FET switching current for load regulation
• Supports isolated and non-isolated buck topologies
• Closed loop soft-start for no overshoot
• OFFREF feature to set dimming off-point to improve fixture
performance matching
• -40°C to +125°C operation
• Pb-free (RoHS compliant)
EMI Filter
AC Mains
1
VDD
14 DHC
5
CS+
AC 12
OUT 16
ISL1903
8 DELADJ
OC 6
13 GND
VERR 9
3 VREF
RAMP
10
FB 7
IOUT
4
100
90
80
70
60
50
40
30
20
10
0
100 90 80 70 60 50 40 30 20 10
CONDUCTION ANGLE (%)
0
FIGURE 1A. BOOST-RETURN (BUCK) TOPOLOGY
FIGURE 1B. CURRENT vs AC CONDUCTION ANGLE
FIGURE 1. ISL1903 APPLICATION PERFORMANCE
FN8285 Rev 1.00
September 20, 2012
Page 1 of 19

ISL1903
Functional Block Diagram - ISL1903
VREF
VDD
GND
UVLO
+
-
BG
OTP
SHUTDOWN
150°C TO 170°C
BIAS AND
REFERENCE
GENERATOR
BIAS/UVLO/OTP
DUTY CYCLE TO
VOLTAGE CONVERTER
LOW PASS FILTER
REFERENCE OUT
MASTER
OSCILLATOR
CLK
TRIANGLE WAVE
GENERATOR
CLK
DIMMING PWM
-
+
AC
OFFREF
IOUT
CS+
DELADJ
OC
RAMP
PEAK
REF
DAECTEDCETTOERCTION
-
+
AC-PRESENT
+
-
ISENSE
PRIMARY CURRENT
SENSE PROCESSOR
IOUT
MINIMUM DIMMING LEVEL
CONTROL
+
-
INHIBIT
REFINBUFF
+
+
_
REFERENCE
SS BUFFER
-
+
CRCM
DETECTOR
QUASI-ZVS
DELAY
FMAX
CLAMP
FMIN
CLAMP
LEADING
EDGE
BLANKING
+
600mV -
PRIMARY OC
200mV
VERR/5
SS/5
+
-- PWM
COMPARATOR
1/5 1/5
EA1
+
-
SQ
RQ
PWM LATCH
PWM
SS
REFINBUFF
VERR
CRCM OSCILLATOR/PWM/ERROR AMPLIFIERS
VERR
FB1
INHIBIT
REFERENCE SS
VERR CLAMP
-
+
SOFT-START/POR/OVP
DHC
PWMOUT
OUT
+
- 1.50V
SS
ENABLE
300ms
SOFT-START
OVP
SS LOW +
-
0.25V
FAULT LATCH
SQ
RQ




@ 2014 :: Datasheetspdf.com :: Semiconductors datasheet search & download site (Privacy Policy & Contact)