Datasheet

TPS2458

SLUS916B –FEBRUARY 2009–REVISED MAY 2010

www.ti.com

APPLICATION INFORMATION

The TPS2458 has been designed to simplify compliance with the PICMG-AMC.R2.0 and PICMG-MTCA.0

specifications. These specifications were developed by the PCI Industrial Computer Manufacturers Group

(PICMG). These two specifications are derivations of the PICMG-ATCA (Advanced Telecommunication

Computing Architecture) specification originally released in December, 2002.

PICMG-AMC Highlights

• AMC – Advanced Mezzanine Cards

• Designed to Plug into ATCA Carrier Boards

• AdvancedMC™ Focuses on Low Cost

• 1 to 8 AdvancedMC™ per ATCA Carrier Board

• 3.3-V Management Power – Maximum Current Draw of 150 mA

• 12-V Payload Power – Converted to Required Voltages on AMC

• Maximum 80 W Dissipation per AdvancedMC™

• Hotswap and Current Limiting and must be Present on Carrier Board

• For details, see www.picmg.org/

PICMG-MTCA Highlights

• MTCA – MicroTelecommunications Computing Architecture

• Architecture for Using AMCs without an ATCA Carrier Board

• Up to 12 AMCs per System, plus Two MicroTCA Carrier Hub (MCH)s, plus Two Cooling Units (CU)s

• Focuses on Low Cost – Commoditizes the Hardware

• All Functions of ATCA Carrier Board must be Provided

• MicroTCA is also known as MTCA, mTCA, mTCA or uTCA

• For details, see www.picmg.org/

Introduction

The TPS2458 has a 12-V power path and a 3.3-V power path. The TPS2458 is in a 32-pin QFN package. The

following sections describe the main functions of the TPS2458 and provide guidance for designing systems using

this device.

Control Logic and Power-On Reset

The TPS2458 circuitry draws power from an internal bus fed by a preregulator. A capacitor attached to the VINT

pin provides decoupling and output filtering for this preregulator. It can draw power from either of two inputs

(IN12 or IN3) or from either of the two outputs (OUT12 or OUT3). This feature allows the internal circuitry to

function regardless of which channels receive power, or from what source. The two external FET drive pins

(PASS, and BLK) are held low during startup to ensure that the 12-V channel remains off. The internal 3.3-V

channel is also held off. When the voltage on the internal VINT rail exceeds approximately 1 V, the power-on

reset circuit initializes the TPS2458.

Product Folder Link(s): TPS2458