Overview
The Analog Devices ADP3610 is a voltage doubler utilizing a switched-capacitor converter based on the push-pull principle. The output switching frequency is approximately 550 kHz. The push-pull concept involves two charge pumps operating in parallel but in opposite phases to generate the output voltage and current. While one capacitor supplies current to the output, the other is being charged, reducing voltage losses and output ripple. The converter operates with input voltages ranging from 3 to 3.6 V, delivering an output of approximately 6 V at a maximum current of 320 mA when using 2.2 µF switched capacitors with low ESR (equivalent series resistance).
Hardware Components
To make switching voltage regulator, you’ll need the following components to get started:
| S.no | Components | Value | Qty |
|---|---|---|---|
| 1 | Integrated Circuit IC | IC1=ADP3610 | 1 |
| 2 | Capacitors | CIN1,CIN2=1uF CP1,CP2=2u2 CO=1uF | 2 2 1 |
Schematic
A shut-down input is available, allowing the voltage doubler to be controlled by a logic-level signal for enabling or disabling the device. The IC is housed in a specialized package capable of dissipating up to 980 mW at room temperature. The schematic illustrates a typical application of the ADP3610 functioning as a non-regulated voltage doubler. In theory, a voltage doubler can provide exactly twice the input voltage at its output. However, in practice, internal losses in the electronic switches and the resistances of the capacitors cause the output voltage to be slightly lower. The output voltage decreases from a no-load value of 6 V to 5.4 V under a 320 mA load, following an almost linear characteristic.
A small capacitor is placed across the two supply pins at the input of the IC to suppress noise, brief voltage fluctuations, and current spikes during the switching operations of the ADP3610. This input capacitor (CIN) should have a low equivalent series resistance (ESR). A larger capacitance is required if the supply leads to the ADP3610 are long. The 1 µF output capacitor (CO) is alternately charged by the charge pump capacitors, CP1 and CP2. The internal resistance plays a key role here, as it largely determines the voltage drop under load and the output voltage ripple. Ceramic or tantalum capacitors are recommended for this purpose. ESR can also be minimized by connecting multiple smaller-value capacitors in parallel. For lighter loads, the value of CO can be reduced.
Conclusion
In summary, the ADP3610 IC is a compact and efficient solution for switching voltage regulation with a voltage doubling feature. It offers stable performance, minimizes voltage losses and ripple, and supports up to 6V at 320mA. Key to its performance is the use of low ESR capacitors, making it suitable for applications that require reliable, low-noise voltage regulation.
