DocumentationDatasheet
Reliability Data
cad_symbol
Features
- High Efficiency: Up to 95%
- 1.8V/800mA Fixed Output and 400mA Adjustable Output Voltage
- Only 40μA Quiescent Current (Both Channels)
- 2.25MHz Constant Frequency Operation
- High Switch Current Limits: 1.2A and 0.7A
- No Schottky Diodes Required
- Low RDS(ON) Internal Switches: 0.35Ω
- Current Mode Operation for Excellent Line and Load Transient Response
- Short-Circuit Protected
- Low Dropout Operation: 100% Duty Cycle
- Ultralow Shutdown Current: IQ < 1μA
- Power-On Reset Output
- Externally Synchronizable Oscillator
- Small Thermally Enhanced 3mm × 3mm DFN Package
Typical Application
Description
The LTC®3548-2 is a dual, 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 ≤1.2mm. For channel 1, the output voltage is fixed at 1.8V/800mA; for channel 2, the output voltage is adjustable from 0.6V to VIN. Internal synchronous 0.35Ω, 1.2A/0.7A power switches provide high efficiency without the need for external Schottky diodes.
A user selectable mode input is provided to allow the user to trade-off noise ripple for low power efficiency. Burst Mode® operation provides high efficiency at light loads, while Pulse Skip Mode provides low noise ripple at light loads.
To further maximize battery run time, 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.
| 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
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.