Documentation
OverviewFeatures
- LTC3887-1 Phase Extender
- Operates with Power Blocks, DrMOS or External Gate Drivers and MOSFETs
- Cascade with Multiple Chips for Very Large Current Applications
- Accurate PolyPhase Current Sharing
- EXTVCC Capable of 5V to 14V Input
- Wide VIN Range: 4.5V to 60V
- Wide Output Voltage Range : 0.5V to 14V
- Wide SYNC Frequency Range: 100kHz to 1MHz
- Pin Programmable CCM/DCM Operation
- Pin Programmable Phase-Shift Control
- Available in a 24-Pin (4mm × 4mm) QFN Package
Typical Application
Description
The LTC®3870-1 is a PolyPhase® step-down slave controller specially designed for multiphase operation with LTC's digital power system management DC/DC controllers. It provides a small and cost effective solution for supplying very large currents by cascading it with a LTC3887-1 controller. A peak current mode architecture provides the LTC3870-1 with excellent current sharing from phase to phase and from chip to chip.
Coherently working with the LTC3887-1, the LTC3870-1 does not require additional I2C addresses, and it supports all programmable features as well as fault protection. The constant switching frequency can be synchronized to an external clock from the LTC3887-1 over a range of 100kHz to 1MHz.
| Onboard MOSFET Gate Drivers | Package | |
| LTC3870 | Yes | 4x5 QFN-28 |
| LTC3870-1 | No – Works with DrMOS and Power Blocks | 4x4 QFN-24 |
4x4 QFN-24
Package Variations and Pricing
| Part Number | Package | Pins | Temp | Price (1-99) |
Price (1k)* |
|---|---|---|---|---|---|
| LTC3870EUFD#PBF | QFN | 28 | E | $3.36 | $2.35 |
| LTC3870EUFD#TRPBF | QFN | 28 | E | $2.41 | |
| LTC3870IUFD#PBF | QFN | 28 | I | $3.62 | $2.53 |
| LTC3870IUFD#TRPBF | QFN | 28 | I | $2.59 | |
| LTC3870EUF-1#TRPBF | QFN | 24 | E | $2.41 | |
| LTC3870IUF-1#PBF | QFN | 24 | I | $3.62 | $2.53 |
| LTC3870IUF-1#TRPBF | QFN | 24 | I | $2.59 | |
| LTC3870EUF-1#PBF | QFN | 24 | E | $3.36 | $2.35 |
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 |
|---|---|---|---|
| DC2454A | LTC3887EUJ-1/LTC3870EUF-1 Demo Board | Dual Phase PMBus Buck Controller with Slave Controller, 7V ≤ VIN ≤ 14V, 0.8V ≤ VOUT ≤ 1.8V @ 100A | Contact Factory |