| Part Number | LTC3855EFE | LTC3859EFE | 
|---|---|---|
| Manufacturer | Analog Devices Inc. | Analog Devices Inc. | 
| Category | PMIC - Voltage Regulators - DC DC Switching Controllers | PMIC - Voltage Regulators - DC DC Switching Controllers | 
| 
                             | 
                                                        
                             | 
                                                    |
| Product Status | Obsolete | Obsolete | 
| Output Type | Transistor Driver | Transistor Driver | 
| Function | Step-Down | Step-Down, Step-Up/Step-Down | 
| Output Configuration | Positive | Positive | 
| Topology | Buck | Buck, Buck-Boost, SEPIC | 
| Number of Outputs | 2 | 3 | 
| Output Phases | 2 | 2 | 
| Voltage - Supply (Vcc/Vdd) | 4.5V ~ 38V | 4.5V ~ 38V | 
| Frequency - Switching | 250kHz ~ 770kHz | 115kHz ~ 835kHz, 350kHz ~ 535kHz | 
| Duty Cycle (Max) | 95% | 99%, 100% | 
| Synchronous Rectifier | Yes | Yes | 
| Clock Sync | No | No | 
| Serial Interfaces | - | - | 
| Control Features | Current Limit, Enable, Frequency Control, Phase Control, Power Good, Soft Start, Tracking | Enable, Frequency Control, Power Good, Soft Start, Tracking | 
| Operating Temperature | -40°C ~ 85°C (TA) | -40°C ~ 125°C (TJ) | 
| Mounting Type | Surface Mount | Surface Mount | 
| Package / Case | 38-TFSOP (0.173", 4.40mm Width) Exposed Pad | 38-TFSOP (0.173", 4.40mm Width) Exposed Pad | 
| Supplier Device Package | 38-TSSOP-EP | 38-TSSOP-EP |