DocumentationDatasheet
Reliability Data
LT Journal
Press Release
cad_symbol
ltspice
Features
- Dual, 180° Phased Controllers
- 2-Pin VID Output Voltage Programming from 0.6V to 5V
- High Efficiency: Up to 95%
- RSENSE or DCR Current Sensing
- Phase-Lockable Fixed Frequency 250kHz to 770kHz
- Adjustable Current Limit
- Dual N-Channel MOSFET Synchronous Drive
- Wide VIN Range: 4.5V to 38V Operation
- Adjustable Soft-Start Current Ramping or Tracking
- Output OV Protection With Reverse Current Limit
- Power Good Output Voltage Monitor
- 32-Pin 5mm × 5mm QFN and 38-Lead TSSOP Packages
Typical Application
Description
The LTC3865/LTC3865-1 are high performance dual synchronous step-down DC/DC switching regulator controllers that drive all N-channel synchronous power MOSFET stages. A constant frequency current mode architecture allows a phase-lockable frequency of up to 770kHz. Power loss and noise are minimized by operating the two controller output stages out of phase.
OPTI-LOOP® compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. Independent track/soft-start pins for each controller ramp the output voltage during start-up. Current foldback limits MOSFET heat dissipation during short-circuit conditions. The MODE/PLLIN pin selects among Burst Mode® operation, pulse-skipping mode, and continuous inductor current mode. The output voltages can be precisely programmed by pin strapping or external resistors.
The LTC3865/LTC3865-1 are available in low profile (5mm × 5mm) 32-pin QFN and 38-Lead thermally enhanced TSSOP packages.
5x5 QFN-32,TSSOP-38
Package Variations and Pricing
| Part Number | Package | Pins | Temp | Price (1-99) |
Price (1k)* |
|---|---|---|---|---|---|
| LTC3865EFE#PBF | TSSOP | 38 | E | $4.08 | $2.87 |
| LTC3865EFE#TRPBF | TSSOP | 38 | E | $2.93 | |
| LTC3865EUH#PBF | QFN | 32 | E | $3.79 | $2.65 |
| LTC3865EUH#TRPBF | QFN | 32 | E | $2.71 | |
| LTC3865EUH-1#PBF | QFN | 32 | E | $3.79 | $2.65 |
| LTC3865EUH-1#TRPBF | QFN | 32 | E | $2.71 | |
| LTC3865IFE#PBF | TSSOP | 38 | I | $4.47 | $3.14 |
| LTC3865IFE#TRPBF | TSSOP | 38 | I | $3.20 | |
| LTC3865IUH#PBF | QFN | 32 | I | $4.20 | $2.94 |
| LTC3865IUH#TRPBF | QFN | 32 | I | $3.00 | |
| LTC3865IUH-1#PBF | QFN | 32 | I | $4.20 | $2.94 |
| LTC3865IUH-1#TRPBF | QFN | 32 | I | $3.00 |
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 |
|---|---|---|---|
| DC1479A | LTC3865EUH Demo Board | 4.5V ≤ VIN ≤ 14V, VOUT1 = 1.5V @ 15A, VOUT2 =1.2V @ 15A | Contact Factory | |
| DC1480A | LTC3865EUH-1 Demo Board | 4.5V ≤ VIN ≤ 14V, VOUT1 = 3.3V @ 5A, VOUT2 =1.8V @ 5A | Contact Factory |