Overview
The LTC3226EUD#TRPBF, produced by Analog Devices Inc., is a 2-cell series supercapacitor charger with a backup PowerPath controller. This integrated circuit is designed to manage power efficiently between a supercapacitor stack and a load, ensuring continuous operation even when the primary power source is unavailable. The LTC3226 features a charge pump and an internal Low Dropout (LDO) regulator, enabling it to charge the supercapacitor stack and supply the load from the stored energy when necessary.
Key Specifications
| Parameter | Min | Typ | Max | Units |
|---|---|---|---|---|
| VIN Input Supply Range | 2.5 | 5.5 | V | |
| VIN Quiescent Current in Normal Mode | 10 | μA | ||
| CPO Quiescent Current in Normal Mode | 20 | μA | ||
| Operating Junction Temperature Range | –40 | 125 | °C | |
| Storage Temperature Range | –65 | 150 | °C | |
| Input High Voltage (EN_CHG, PFI) | 1.3 | V | ||
| Input Low Voltage (EN_CHG, PFI) | 0.4 | V |
Key Features
- Dual Mode Operation: The LTC3226 operates in normal and backup modes. In normal mode, power flows from VIN to VOUT through an external FET, and the internal charge pump tops off the supercapacitor stack. In backup mode, the charge pump is turned off, the external FET is turned off, and the LDO supplies the load current from the stored charge.
- Charge Pump: A dual-mode, low-noise, constant frequency (0.9MHz) charge pump is integrated to charge the supercapacitor stack efficiently.
- Internal LDO Regulator: An internal LDO regulator ensures a stable output voltage during backup mode, regulated by an external resistor divider.
- PowerPath Controller: The device includes a PowerPath controller that manages the transition between the primary power source and the backup power from the supercapacitor stack.
- External FET Gate Pin: The GATE pin is driven by an internal ideal diode controller to regulate VOUT to 15mV below VIN.
- Reset Comparator Input: The RST_FB pin controls the state of the RST output pin with a 0.74V falling threshold and 20mV hysteresis.
Applications
- Backup Power Systems: Ideal for systems requiring backup power during primary power source failures, such as in industrial control systems, medical devices, and communication equipment.
- Energy Harvesting: Suitable for energy harvesting applications where supercapacitors are used to store energy from intermittent sources.
- Power Management in IoT Devices: Useful in IoT devices that require efficient power management and backup power capabilities.
- Automotive Systems: Can be used in automotive systems for backup power and voltage regulation.
Q & A
- What is the primary function of the LTC3226?
The primary function of the LTC3226 is to charge a 2-cell supercapacitor stack and provide backup power to the load when the primary power source is unavailable.
- What are the operating modes of the LTC3226?
The LTC3226 operates in two modes: normal mode and backup mode. In normal mode, power flows from VIN to VOUT, and the charge pump tops off the supercapacitor stack. In backup mode, the charge pump is off, and the LDO supplies the load from the stored charge.
- What is the input voltage range for the LTC3226?
The input voltage range for the LTC3226 is from 2.5V to 5.5V.
- What is the purpose of the internal LDO regulator?
The internal LDO regulator ensures a stable output voltage during backup mode, regulated by an external resistor divider.
- How does the PowerPath controller work?
The PowerPath controller manages the transition between the primary power source and the backup power from the supercapacitor stack, ensuring continuous operation of the load.
- What is the role of the GATE pin in the LTC3226?
The GATE pin is driven by an internal ideal diode controller to regulate VOUT to 15mV below VIN.
- What is the significance of the RST_FB pin?
The RST_FB pin controls the state of the RST output pin with a 0.74V falling threshold and 20mV hysteresis.
- What are some typical applications of the LTC3226?
The LTC3226 is typically used in backup power systems, energy harvesting applications, power management in IoT devices, and automotive systems.
- What is the operating junction temperature range of the LTC3226?
The operating junction temperature range of the LTC3226 is from –40°C to 125°C.
- How should the exposed pad of the LTC3226 package be handled?
The exposed pad of the LTC3226 package must be soldered to the PCB ground plane to ensure proper thermal performance.
