LM1770 #7: 0.9V @ 3A, 3.3V in, (Page 13)

Summary

The controller utilizes a constant on-time control scheme which eliminates the need for external compensation components, allowing the power supply designer to minimize necessary board space and reduce costs.

This design operates at a higher frequency as compared to the 0.8V design above. This facilitates the use of a smaller 3.3 µH inductor which allows the complete power supply to fit on the LM1770 evaluation board PCB. The output is set at 0.9V to provide a VTT voltage for use in DDR2 applications. The design is capable of both sinking and sourcing current.

Specifications

Manufacturer	Texas Instruments
Category	AC/DC and DC/DC Conversion
Sub-Category	DC/DC SMPS - Single Output
Eval Board	Board not Stocked
Topology	Step Down
Outputs and Type	1 Non-Isolated
Voltage Out: Factory Set	0.9 V
Current Out	3 A
Voltage In	3.3 V
Efficiency @ Conditions	>82%, 3.3V in, 0.9V @ 800 mA ~ 1.2 A >76%, 3.3V in, 0.9V @ 300 mA ~ 3 A
Voltage Out Range
Features	Short Circuit Protection Soft Start
Switching Frequency	545 kHz
Standby Current [Typical]
Quiescent Current [Typical]	400 µA
Component Count + Extras	9 + 0
Internal Switch	No
Design Author	Texas Instruments
Application / Target Market	Computers DVD/Blu-ray Players Point of Load (PoL) Portable Devices Set-Top Boxes Telecom USB Powered Devices White Goods
Standby Current [Maximum]
Quiescent Current [Maximum]	600 µA
Main I.C. Base Part	LM1770S
Date Created By Author
Date Added To Library	2015-04