The ADP1612 is a step-up DC-to-DC switching regulator (also called a boost converter) manufactured by Analog Devices. It is designed to convert a lower input voltage to a higher output voltage efficiently.
A typical step-up (boost) regulator configuration using the ADP1612 or ADP1613 is shown in figure below.
Both ICs are nearly identical, with the primary difference being their switching frequency, which affects their pulse-width modulation (PWM) performance.
These regulators use PWM control and can achieve efficiencies of up to 94%, depending on the output voltage and load current, as illustrated in the figure below.
Generally, as the load current increases, the efficiency improves, while changes in output voltage have a smaller effect.
The operating frequency is selectable via pin 7 (FREQ):
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650 kHz: For better efficiency and when larger external components are acceptable. Achieved by grounding pin 7 or leaving it floating.
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1.3 MHz: For smaller external components, at the cost of slightly lower efficiency. Set by connecting pin 7 to VIN (pin 6).
The regulator accepts an input voltage range of 1.8 V to 5.5 V and can boost the output voltage up to 20 V.
To ensure reliable operation, the device includes:
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Thermal shutdown (TSD) protection, which disables the regulator above 150°C and re-enables it at 130°C.
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Under-voltage lockout (UVLO), which disables the output when the input voltage falls below the safe operating threshold.
Additional pins and components:
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Pin 8 (SS – Soft Start): Connect a capacitor to limit inrush current during power-up.
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Pin 3 (EN – Enable): Used to turn the regulator on or off.
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Pin 1 (COMP): Requires a series RC network for loop compensation.
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Pin 2 (FB – Feedback): Connects to a resistor voltage divider to regulate the output voltage.
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Pin 5 (SW – Switch Output): Connect an inductor between VIN and SW, and a Schottky diode from SW to VOUT for fast switching performance.
This design makes the ADP1612/1613 an efficient and flexible solution for applications that require converting a low supply voltage to a higher one.
Here's a detailed overview of its features and applications:
🔧 Key Features:
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Type: Step-Up (Boost) Switching Regulator
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Input Voltage Range: 1.8 V to 5.5 V
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Output Voltage Range: Up to 20 V
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Switching Frequency: 650 kHz (fixed)
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Maximum Output Current: Typically up to 1.3 A (depends on Vin, Vout)
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Internal Power Switch: Integrated 1.6 A, 0.13 Ω N-channel MOSFET
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Soft-Start Function: Limits inrush current at power-up
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Enable Pin: Allows on/off control
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Current-Mode PWM Control: For fast transient response and good stability
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Compact Package: Available in 8-lead MSOP and 3 mm × 3 mm LFCSP
⚙️ Typical Applications:
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TFT LCD Bias Supplies
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OLED Displays
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Industrial and Medical Instruments
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Portable and Battery-Powered Devices
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Low-Voltage Microcontroller or Sensor Systems needing a higher voltage
🧰 Basic Application Circuit:
In a basic configuration, you connect:
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Input: 1.8V to 5.5V (from batteries or low-voltage rails)
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Inductor: Between the input and switch pin
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Diode: Schottky diode for fast switching
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Output Capacitor: To filter output
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Feedback Divider: To set the output voltage using a resistor divider to the FB pin
🧮 Output Voltage Equation:
To set the output voltage, use:
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Where ≈ 1.23 V
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and are the resistors in the feedback voltage divider
🔋 Example Use Case:
If you have a 3.3 V supply (like from a Li-ion battery) and you need 12 V for an op-amp or LCD backlight, the ADP1612 can step up that voltage with good efficiency.
An alternative to this is the MT3608 boost converter or you could build your own with 555 Timer, see boost converter with 555 timer.
