DocumentationDatasheet
Reliability Data
cad_symbol
Features
- High Efficiency: Up to 95%
- 1.8V at 800mA/1.575V at 400mA
- Very Low Quiescent Current: Only 40µA
- 2.25MHz Constant Frequency Operation
- High Switch Current: 1.2A and 0.7A
- No Schottky Diodes Required
- VIN: 2.5V to 5.5V
- Current Mode Operation for Excellent Line and Load Transient Response
- Short-Circuit Protected
- Low Dropout Operation: 100% Duty Cycle
- Ultralow Shutdown Current: IQ < 1µA
- Small Thermally Enhanced 3mm × 3mm DFN Packages
Typical Application
Description
The LTC®3548-1 is a dual, fixed output, constant frequency, synchronous step-down DC/DC converter. Intended for low power applications, it operates from 2.5V to 5.5V input voltage range and has a constant 2.25MHz switching frequency, allowing the use of tiny, low cost capacitors and inductors with a profile ≤1mm. The output voltage for channel 1 is fixed at 1.8V and for channel 2 is fixed at 1.575V. Internal synchronous 0.35Ω, 1.2A/0.7A power switches provide high efficiency without the need for external Schottky diodes. Burst Mode® operation provides high efficiency at light loads.
To further maximize battery runtime, the P-channel MOSFETs are turned on continuously in dropout (100% duty cycle), and both channels draw a total quiescent current of only 40µA. In shutdown, the device draws <1µA.
The LTC3548-1 is available in both thin (0.75mm) and ultra-thin (0.55mm) 3mm x 3mm DFN packages.
| Features | |
| LTC3548A | Improved Burst Mode, Improved ESD, 2 Adjustable Outputs |
| LTC3548-2 | One Fixed 1.8V Output, 1 Adjustable |
| LTC3548-1 | Fixed 1.8V and 1.575V Outputs |
| LTC3548 | 2 Adjustable Outputs |
3x3 DFN-10,3x3 UTDFN-10
Package Variations and Pricing
| Part Number | Package | Pins | Temp | Price (1-99) |
Price (1k)* |
|---|---|---|---|---|---|
| LTC3548AEDD#PBF | DFN | 10 | E | $3.71 | $2.60 |
| LTC3548AEDD#TRPBF | DFN | 10 | E | $2.66 | |
| LTC3548AEMSE#PBF | MSOP | 10 | E | $3.71 | $2.60 |
| LTC3548AEMSE#TRPBF | MSOP | 10 | E | $2.66 | |
| LTC3548AIDD#PBF | DFN | 10 | I | $4.27 | $2.99 |
| LTC3548AIDD#TRPBF | DFN | 10 | I | $3.05 | |
| LTC3548AIMSE#PBF | MSOP | 10 | I | $4.27 | $2.99 |
| LTC3548AIMSE#TRPBF | MSOP | 10 | I | $3.05 | |
| LTC3548EDD#PBF | DFN | 10 | E | $3.71 | $2.60 |
| LTC3548EDD#TRPBF | DFN | 10 | E | $2.66 | |
| LTC3548EDD-1#PBF | DFN | 10 | E | $3.71 | $2.60 |
| LTC3548EDD-1#TRPBF | DFN | 10 | E | $2.66 | |
| LTC3548EDD-2#PBF | DFN | 10 | E | $3.71 | $2.60 |
| LTC3548EDD-2#TRPBF | DFN | 10 | E | $2.66 | |
| LTC3548EKD-1#PBF | UTDFN | 10 | E | $4.18 | $2.71 |
| LTC3548EKD-1#TRPBF | UTDFN | 10 | E | $2.66 | |
| LTC3548EMSE#PBF | MSOP | 10 | E | $3.71 | $2.60 |
| LTC3548EMSE#TRPBF | MSOP | 10 | E | $2.66 | |
| LTC3548IDD#PBF | DFN | 10 | I | $4.27 | $2.99 |
| LTC3548IDD#TRPBF | DFN | 10 | I | $3.05 | |
| LTC3548IMSE#PBF | MSOP | 10 | I | $4.27 | $2.99 |
| LTC3548IMSE#TRPBF | MSOP | 10 | I | $3.05 | |
| LTC3548EMSE | MSOP | 10 | E | $7.42 | $5.20 |
| LTC3548EMSE#TR | MSOP | 10 | E | $5.32 | |
| LTC3548EDD | DFN | 10 | E | $7.42 | $5.20 |
| LTC3548EDD#TR | DFN | 10 | E | $5.32 | |
| LTC3548EDD-1 | DFN | 10 | E | $7.42 | $5.20 |
| LTC3548EDD-1#TR | DFN | 10 | E | $5.32 | |
| LTC3548EDD-2 | DFN | 10 | E | $7.42 | $5.20 |
| LTC3548EDD-2#TR | DFN | 10 | E | $5.32 | |
| LTC3548IDD | DFN | 10 | I | $8.54 | $5.98 |
| LTC3548IDD#TR | DFN | 10 | I | $6.10 | |
| LTC3548IMSE | MSOP | 10 | I | $8.54 | $5.98 |
| LTC3548IMSE#TR | MSOP | 10 | I | $6.10 |
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.