PTB78560A_15 Datasheet, PDF (1/27 Pages) Texas Instruments – 30-W, 24-V/48-V INPUT DC/DC CONVERTERS WITH AUTO-TRACK™ SEQUENCING

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PTB78560A, PTB78560B
PTB78560C
SLTS249 – JUNE 2005
30-W, 24-V/48-V INPUT DC/DC CONVERTERS
WITH AUTO-TRACK™ SEQUENCING
FEATURES
• Input Voltage: 18 V to 60 V
• 30-W Total Output Power
• Output Voltages: 3.3 V, 5 V, and 12 V
• Wide-Output Adjust/Trim
• Up To 88% Efficiency
• Overcurrent Protection
• Overtemperature Shutdown
• Undervoltage Lockout
• Input Overvoltage Protection
• Auto-Track™ Power-Up Sequencing
(Includes Sequenced Output with PTB78560B)
• Smart-Sense Remote Sensing (PTB78560B)
• Dual-Logic Enable Control
• Space-Saving 1×2 Footprint
• Surface Mount Package
• Lead (Pb) - Free Option Available
• 1500-Vdc Isolation
• Agency Approvals (Pending):
UL/cUL 60950, EN 60950
APPLICATIONS
• Intermediate Bus Architectures
• Telecom, High-End Computing Platforms
• Multi-Rail Power Systems with
Power-Up Sequencing
DESCRIPTION
The PTB78560x is a series of 30–W rated isolated dc/dc converters, designed to operate from a standard 24–V
or 48–V telecom central office (CO) supply. Housed in a 1×2 package, each model has a wide-adjust output
voltage that can be set to one of the common intermediate bus voltages of 3.3 V, 5 V, or 12 V.
The PTB78560 series incorporates Auto-Track™, a feature that simplifies the power-up sequencing of multiple
power modules that operate from the same intermediate bus. During a power-up cycle, modules with this feature
have the capability of following a common ramp voltage applied to an input called Track. The PTB78560 series
is specifically designed to control the Track voltage of any number of nonisolated downstream modules powered
from its output. This ensures that the outputs of the downstream modules all rise simultaneously during power
up. The PTB78560B (3.3 V) has an additional sequenced output, V_O Seq, which also rises with the Track
voltage. This allows the V_O Seq output to power up simultaneously with the outputs from other power modules
under the control of Auto-Track.
Whether used to facilitate power-up sequencing, or operated as a stand-alone module, the PTB78560 series
includes many other features expected of high-performance dc/dc converter modules. Precise output voltage
regulation is ensured with a differential remote sense. Operational features include an input undervoltage lockout
(UVLO) and a dual-logic output enable control. Overcurrent and overtemperature protection ensure survival
against load faults.
Typical applications include distributed power architectures in both telecom and computing environments,
particularly complex digital systems requiring power sequencing of multiple power supply rails.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
Auto-Track is a trademark of Texas Instruments.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2005, Texas Instruments Incorporated