IR21592S International Rectifier, IR21592S Datasheet - Page 20

• Manufacturer Part Number: IR21592S
• Description: IC CNTRLR BALLAST DIMMING 16SOIC
• Manufacturer: International Rectifier
• Type: Ballast Controllerr

Specifications of IR21592S

• Frequency: 73 ~ 108 kHz
• Current - Supply: 10mA
• Voltage - Supply: 12.5 V ~ 15.6 V
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 16-SOIC (3.9mm Width)
• Package: 16-lead SOIC Narrow
• Circuit: Fluorescent Ballast IC
• Offset Voltage (v): 600
• Output Source Current Min (ma): null
• Output Sink Current Min (ma): null
• Vcc Range (v): 12-25V with UVLO
• Output Voltage Min (v): 10
• Output Voltage Max (v): 20
• Pbf: PbF Option Available
• For Use With: IRPLDIM2U - BALLAST DIM DIG 32W/T8 120VAC
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Current - Output: -
• Other names: *IR21592S

IR21592/IR21593
The charging time of CT from 1V to 5.1V
determines the on-time of output gate drivers HO
and LO and corresponds to -180 degrees of
possible phase shift in load current (minus
deadtime). For the 0 to -90 degree dim range, the
voltage on pin MIN is bounded between 1V and
3V using pins MIN and MAX. An external resistor
on pin MAX programs the minimum phase shift
reference (maximum lamp power) corresponding
to 5V on pin DIM, and an external resistor on pin
MIN sets the maximum phase shift (minimum
lamp power) corresponding to 0.5V on pin DIM.
Current Sensing
During dimming, the current sensing circuitry
(Figure 15) detects over-current which can occur
during hard-switching (see Fault section), and
zero-crossing to measure the phase of the total
load current. To reject any switching noise which
can occur at the turn-on of the low-side MOSFET
or IGBT, a digital current sense blanking circuit
blanks out the signal from the zero-crossing
20
V
5V
3V
1V
MIN
0
0.5V
R
MIN
Figure 14, Dimming interface
V
DIM
R
MAX
SETTING
USER
5V
REF
LO
V
CT
0
( S ) & ( PbF )
-90
DIM
RANGE
-180
detection comparator for 400ns after LO goes 'high'
(Figure 16).
The internal blank time reduces the dimming range
slightly (Figure 16) when operating at minimum
phase shift (maximum lamp power). The external
programming resistor on pin MAX must be
selected such that the minimum phase shift is
set a safe margin away from the blank time. A
series resistor (R1) is required to limit the amount
of current flowing out of pin CS when the voltage
across RCS goes below -0.7V. A filter capacitor
at pin CS may be required due to other possible
asynchronous noise sources present in the ballast
system.
V
V
BUS
BUS
(+)
(-)
Figure 15, Current sensing circuitry.
CONTROL
PHASE
BLANK
400ns
FAULT
LOGIC
Half
Bridge
Driver
IR2159
1.6V
15
11
10
12
16
HO
CS
COM
VS
LO
R1
www.irf.com
Q2
Q2
RCS
Load
Return
Half
Bridge
Output
I
LOAD