IR21593SPBF International Rectifier, IR21593SPBF Datasheet - Page 17

• Manufacturer Part Number: IR21593SPBF
• Description: IC BALLAST CONTROL DIM 16-SOIC
• Manufacturer: International Rectifier
• Type: Ballast Controllerr

Specifications of IR21593SPBF

• Frequency: 30 ~ 230 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)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Output: -
• Lead Free Status / Rohs Status: RoHS Compliant part

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This feedback keeps the peak preheat current
regulated to the user-programmable setting on pin
IPH for the duration of the preheat time. An
internal current source connected to an external
resistor on pin IPH sets a voltage reference for
the peak pre-heat current. The pre-heat time
continues until the voltage on pin CPH exceeds
5V.
Ignition (IGN)
The IR21592/IR21593 enters ignition mode when
the voltage on pin CPH exceeds 5V. The peak
current regulation reference voltage is
disconnected from the user-programmable
setting on pin IPH and is connected to a higher
internal threshold of 1.6V (Figure 9).
V
Figure 8, Peak load current regulation timing diagram.
I
V
CVCO
CVCO
V
60uA
-1uA
HO
LO
VS
RCS
IPH
t
t
t
t
IR21592/IR21593
The ignition ramp is then initiated as the
capacitor on pin VCO discharges linearly
through an internal 1uA current source. The
frequency decreases linearly towards the
resonance frequency of the high-Q ballast output
stage, causing the lamp voltage and load current
to increase (Figure 10).
continues to decrease until the lamp ignites or
the current limit of the IR21592/IR21593 is
reached. If the current limit is reached, the
IR21592/IR21593 enters FAULT mode. The 1.6V
threshold together with the external current
sensing resistor on pin CS determine the
maximum allowable peak ignition current (and
therefore peak ignition voltage) of the ballast
output stage. The peak ignition current must not
exceed the maximum allowable current ratings
of the output stage MOSFETs or IGBTs, and,
the resonant inductor must not saturate at
any time.
To prevent a "flash" across the lamp during
ignition at low dim settings, an ignition detection
0.5 to 5V
V
V
BUS
BUS
(+)
(-)
C
C
R
Figure 9, IR21592/IR21593 ignition circuitry.
VCO
CPH
DIM
CPH
VCO
DIM
2
3
4
1uA
1uA
7.6V
FAULT
LOGIC
CONTROL
LOGIC
PHASE
INTERFACE
VCO
PH
DIM
IR21592/IR21593
Half
Bridge
Driver
1.6V
The frequency
( S ) & ( PbF )
16
15
11
10
12
HO
VS
LO
CS
COM
Q2
Q2
RCS
Load
Return
Half
Bridge
Output
I
LOAD
17