inductor DC resistance too low for el driver IC: can I still make this circuit work?

Question

I bought an EL lamp driver IC from Microchip, the HV830, but I was not able to find the exact inductor indicated in the test circuit shown below, the Murata LQH4N221K04. I found another 220uH inductor from the same manufacturer, the Murata 11R224C, but it has a lower DC resistance, 2.4 ohms, vs. the recommended 5.4 ohm value. I tried following the values for the test circuit with my replacement inductor, but it is drawing too much current, about 395mA or so. The spec sheet for the inductor says the inductor saturates at 240mA. My output voltage is -6V->2V, a far cry from the -100V->100V typical of this circuit.

I also have a few other minor differences in the circuit: I'm using a short piece of EL wire (1 foot or so) for the load instead of a 3 square inch EL lamp, and a larger bypass capacitor (1 uF instead of .1 uF) since I'm not sure what my power supply impedance is.

First, I tried increasing the switching frequency of the mosfet, from 55 KHz up to 885 KHz, but this did not reduce the current enough to fix the issue.

Then I tried putting a 5 ohm power resistor before the inductor, but I believe this causes 2 issues:

1) the voltage drop across the power resistor is too large, so now the inductor does not get enough voltage to charge the capacitor with inductive flyback. If I step up the voltage enough to compensate for the voltage drop, the inductor saturates due to the higher current (not to mention the other components aren't rated for that much current).

2) I think the inductor will charge at a different rate with the power resistor thrown in the mix. I believe I might be able to compensate for this, as this IC allows me to change the switching frequency of the internal MOSFET with a different Rsw-osc value. Unfortunately, I cannot adjust the duty cycle which I believe is set at 88% on.

So, my question is: is it possible to make this circuit work with my current inductor? I was also able to find a 220uH inductor online with a 7.1 ohm DC resistance, but I haven't tried it yet. Thanks in advance.

EDIT: Here is a technical note for a similar EL driver IC from the same manufacturer:

Answer 1

This is from page 3 of your guide.HV830 UG

Supertex drivers allow adjustable conversion frequency (via RSW-osc), while duty cycle is fixed at a nominal 88% ON time. When designing a driver circuit, it is important to select the inductor and conversion frequency to provide the required output voltage while assuring that inductor current does not approach saturation levels.

If the inductor saturates, excessive current will flow, potentially leading > to device failure.

Ideally, inductor current should be allowed to return to zero between cycles. If inductor current is not allowed to return to zero, a higher average current will be needed to meet output power requirements, increasing I2R losses, and decreasing conversion efficiency.

On the other hand, if too much time is allowed between zero inductor current and the start of the next cycle, more energy will need to be transferred each cycle to maintain output power, thus risking inductor saturation and increasing I2R and core losses.

For most applications, inductors in the range of 100µH to 1mH are appropriate. As a general rule, larger inductor values and lower converter frequencies should be used for lower power applications.

These notes imply that inductor value and Q may be more important than its DC resistance, which has a negative impact on Q, or inductor efficiency.

All things considered equal and no other issues, I would use inductors rated 500 mA or so and 100 uH to 1 mH, per the guidelines. If 220 uH saturated, try 330 uH, etc.