Boost converter or voltage doubler?

Hey guys.

I'm using an Arduino Pro Mini 5V with an XBee, LM35, some LEDs and buzzer powered by a combination of the DC-DC boost converter (0.9-5V to regulated 5V) and newer version of TP4056 charger with DW01 and 8205 ic. A 3.7 V li-ion battery will be used to provide power.

So my problem is, I'm adding an ionization smoke sensor (HIS-07) and A5368CA IC for the sensor, and I don't know where to get the 9 V to power up the sensor. However, I have two ways in mind to address this.

The first is to use an adjustable voltage step-up booster instead of the DC-DC boost converter. I'll supply power to the Arduino's RAW pin instead of VCC so it can accept up to 9V.

Second case is, I'll use a voltage doubler circuit, whose input connection is parallel to Arduino's VCC and GND. This way, I can connect the circuit's output connection to the HIS-07 sensor and the IC.

Which method is more efficient, less noisy andpower hungry? I'm sorry I have no computers with me now and my phone's quite outdated.


  1. VOLTAGE DOUBLER Circuit (BTW, is this circuit good enough? I've seen circuits much simpler than this online)
  2. (A5368 Datasheet)
  3. (HIS-07 pic)
    4. (HIS07 datasheet)

Any diode-capacitor voltage doubler will be very poor at anything but small load currents, very soggy under
load. However that chip only takes 10mA so that may be OK. The sensor itself takes infinitessimal current.

The kind of impedances used in that sensor mean you really need something exotic like teflon pcb for the sensor to IC connection
as it requires greater than 10^14 ohms impedance, which is extreme. One fingerprint in the wrong place
will completely stop the sensor working, and guard electrodes around all the signal paths will be essential.

Some sort of high-performance conformal coating will be required I think to allow the thing to work at
normal humidity levels, although teflon may prove good enough at repelling a water monolayer (most
materials can't).

Hey MarkT. That sounds pretty much very difficult for my level. I'm still a beginner in Arduino. Are there any more options for that? :confused: I'm sorry

A beginner shouldn't be playing with an ionization smoke sensor, also because they contain radioactive material.
There are also optical smoke detector sensors.

@Wawa: But I have seen them being used as well in other projects by students. I do appreciate your concern but I'll be using them only for a while.

Are they really that dangerous? I'm also trying to opt for low power and easier to use sensors, hence the sensor aside from photoelectric which drains battery faster due to its LED and the MQ-range of sensors. Actually, I'm pretty much confused about everything. :confused:

No they are not dangerous, they are sealed and in every smoke detector! You wouldn’t give it
to a small child to play with, obviously, but short of cracking it open and eating it these modules
are safe.

The electronics at such low current levels requires attention to detail - use the wrong material and
it won’t work - almost everyone doing electronics for a hobby would be a beginner for circuitry
requiring 10^14 ohms impedance - so go for it, just be scrupulous with the cleanliness, clean
gloves are required, reading up on guard-rings and so forth.

@Mr.MarkT: Can you check my circuit later? I actually don’t know to use the A5368CA IC and the sensor itself. But here’s one I can use/adapt to my circuit with some few modifications.

Link at:

Sorry, I've never worked at these high impedances, I just know how tricky it is to do (checkout
EEVBlog's video on the picoammeter for a feel for this stuff: EEVblog #406 - Keithley 480 Picoammeter Teardown & Calibration - YouTube )