High Voltage, 1.5A, 500kHz Step-Down Switching Regulators
The LT1956/LT1956-5 is a 500 kHz monolithic buck switching regulator capable of handling input voltages from 5.5 V to 60 V and delivering up to 1.5 A of output current. It features a constant‑frequency current‑mode architecture, low shutdown current (25 pA), and an easily synchronizable external SYNC pin.
The document includes detailed electrical characteristics, pin descriptions, typical performance graphs, recommended layout guidelines, and package dimensions for both the FE (TSSOP) and GN (SSOP) versions. Application notes cover feedback pin functions, foldback current limiting, and design recommendations for setting output voltage.
| Input Voltage Range | 5.5 V to 60 V |
|---|---|
| Peak Switch Current | 1.5 A |
| Switching Frequency | 500 kHz |
| Shutdown Current | 25 pA |
| Fixed Output Voltage (LT1956‑5) | 5 V |
| Effective Supply Current | 2.5 mA |
| SYNC Frequency Range | 580 kHz to 700 kHz |
| Package (FE) | 16‑Lead Plastic TSSOP (4.4 mm) |
| Package (GN) | 16‑Lead Plastic SSOP (narrow 0.150 in) |
The LT1956 operates from 5.5 V up to 60 V.
The LT1956‑5 provides a fixed 5 V output.
Apply a logic‑level signal to the SYNC pin within the 580 kHz to 700 kHz range.
The shutdown current is 25 pA.