IR2159 International Rectifier, IR2159 Datasheet - Page 18

• Manufacturer Part Number: IR2159
• Description: IC BALLAST CONTROL DIM 16-DIP
• Manufacturer: International Rectifier
• Type: Ballast Controllerr

Specifications of IR2159

• Frequency: 25 ~ 95 kHz
• Current - Supply: 10mA
• Voltage - Supply: 12.5 V ~ 15.6 V
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 16-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Current - Output: -

IR2159/IR21591
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 IR2159 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).
18
V
Figure 8, Peak load current regulation timing diagram.
I
V
CVCO
C V C O
60uA
V
-1uA
H O
L O
VS
R C S
IPH
( S )
t
t
t
t
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).
The frequency continues to decrease until the lamp
ignites or the current limit of the IR2159 is reached.
If the current limit is reached, the IR2159 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 decrease until the voltage on pin VCO reaches
VDIMTH, corresponding to the minimum operating
frequency set by the external resistor on pin FMIN,
Should the lamp ignite, the frequency continues
0.5 to 5V
V
V
BUS
BUS
(+)
(-)
C
C
R
VCO
CPH
DIM
CPH
VCO
DIM
Figure 9, IR2159 ignition circuitry.
4
2
3
1uA
1uA
7.6V
FAULT
LOGIC
CONTROL
LOGIC
PHASE
INTERFACE
VCO
PH
DIM
Half
Bridge
Driver
IR2159
1.6V
16
15
11
10
12
HO
VS
LO
CS
COM
www.irf.com
Q2
Q2
RCS
Load
Return
Half
Bridge
Output
I
LOAD