DocumentationDatasheet
Design Note
Reliability Data
LT Journal
Press Release
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Features
- High Efficiency Step-Up/Step-Down Charging of Two Series Supercapacitors
- Automatic Cell Balancing Prevents Capacitor Overvoltage During Charging
- Programmable Charging Current Up to 500mA (Single Inductor), 1A (Dual Inductor)
- VIN = 2.7V to 5.5V
- Selectable 2.4V/2.65V Regulation per Cell (LTC3625)
- Selectable 2V/2.25V Regulation per Cell (LTC3625-1)
- Low No-Load Quiescent Current: 23μA
- IVOUT, IVIN < 1μA in Shutdown
- Low Profile 12-lead 3mm × 4mm DFN Package
Typical Application
Description
The LTC3625/LTC3625-1 are programmable supercapacitor chargers designed to charge two supercapacitors in series to a fixed output voltage (4.8V/5.3V or 4V/4.5V selectable) from a 2.7V to 5.5V input supply. Automatic cell balancing prevents overvoltage damage to either supercapacitor while maximizing charge rate. No balancing resistors are required.
High efficiency, high charging current, low quiescent current and low minimum external parts count (one inductor, one bypass capacitor at VIN and one programming resistor) make the LTC3625/LTC3625-1 ideally suited for small form factor backup or high peak power systems.
Charging current/maximum input current level is programmed with an external resistor. When the input supply is removed and/or the EN pin is low, the LTC3625/LTC3625-1 automatically enter a low current state, drawing less than 1μA from the supercapacitors.
The LTC3625/LTC3625-1 are available in a compact 12‑lead 3mm × 4mm × 0.75mm DFN package.
4x3 DFN-12
Package Variations and Pricing
| Part Number | Package | Pins | Temp | Price (1-99) |
Price (1k)* |
|---|---|---|---|---|---|
| LTC3625EDE#PBF | DFN | 12 | E | $4.29 | $3.00 |
| LTC3625EDE#TRPBF | DFN | 12 | E | $3.06 | |
| LTC3625EDE-1#PBF | DFN | 12 | E | $4.29 | $3.00 |
| LTC3625EDE-1#TRPBF | DFN | 12 | E | $3.06 | |
| LTC3625IDE#PBF | DFN | 12 | I | $4.93 | $3.45 |
| LTC3625IDE#TRPBF | DFN | 12 | I | $3.51 | |
| LTC3625IDE-1#PBF | DFN | 12 | I | $4.93 | $3.45 |
| LTC3625IDE-1#TRPBF | DFN | 12 | I | $3.51 |
Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.
| Part Number | Description | Price | Documentation |
|---|---|---|---|
| DC1583A-A | LTC3625EDE Demo Board | VIN = 2.7V to 5.5V, VOUT= 5.3V / 4.8V @IOUT up to 1A | $125.00 | |
| DC1583A-B | LTC3625-1EDE Demo Board | VIN = 2.7V to 5.5V, VOUT= 4.5V or 4.0V @ IOUT up to 1A | $125.00 |