IRPLLNR2U International Rectifier, IRPLLNR2U Datasheet - Page 6

• Manufacturer Part Number: IRPLLNR2U
• Description: BALLAST 32W/T8 120V AC IR21571
• Manufacturer: International Rectifier

Specifications of IRPLLNR2U

• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: *IRPLLNR2U

Power Factor Correction
The power factor correction section consists of the Motorola Semiconductor MC34262 Power Factor
Controller IC (IC1), MOSFET M1, inductor L2, diode D2, capacitor C8 and additional biasing, sens-
ing and compensation components (see schematic diagram). The IC was chosen for its minimal
component count, low start-up supply current and robust error amplifier. This is a boost topology
designed to step-up and regulate the output DC bus voltage while drawing sinusoidal current from
the line (low THD) which is “in phase” with the AC input line voltage (HPF). The design of the power
factor correction section was taken from the Motorola Semiconductor MC34262 data sheet and
information on the operation and design considerations for the MC34262 are contained therein.
Ballast Control
The ballast control section is built around the IR21571 Ballast Control IC, IC2 of the Demo board.
The IR21571 contains an oscillator, a high voltage half-bridge gate driver and lamp fault protection
circuitry. A block diagram of the IR21571 IC is shown in figure 1 and a state diagram of the IR21571
is shown in figure 2. Following is a breakdown of the operation of the ballast in all of the different
modes of operation.
6
RUN
CPH
RPH
VDC
OC
RT
CT
DT
1
2
7.6V
3
4
5
6
7
8
7.6V
I
CT
50uA
I
= I
RT
3.0V
5.1V
5.1V
4.0V
RT
1.0uA
2.0V
VOLTAGE
UNDER-
DETECT
4.0V
2.0V
R
S
Q
Q
Figure 1: IR21571 Block Diagram
R1
R2 Q
S
Q
Q
Q
S
R
R
T
DETECT
OVER-
TEMP
Q
Q
Q
Q
LEVEL
SHIFT
CLK
R
D
FILTER &
PULSE
LATCH
2.0V
15.6V
7.6V
0.2V
www.irf.com
7.6V
14
16
15
13
11
12
10
9
COM
VCC
HO
VB
VS
LO
CS
SD