Datasheet Linear Technology LTC1703

Manufacturer	Linear Technology
Series	LTC1703

Dual 550kHz Synchronous 2-Phase Switching Regulator Controller with 5-Bit VID

Datasheets

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PDF, 394 Kb, Revision: A, File uploaded: Sep 20, 2017

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Packaging

	LTC1703CG#PBF	LTC1703CG#TRPBF	LTC1703IG#PBF	LTC1703IG#TRPBF
N	1	2	3	4
Package	SSOP-28 Package Outline Drawing	SSOP-28 Package Outline Drawing	SSOP-28 Package Outline Drawing	SSOP-28 Package Outline Drawing
Package Code	G	G	G	G
Package Index	05-08-1640 (G28)	05-08-1640 (G28)	05-08-1640 (G28)	05-08-1640 (G28)
Pin Count	28	28	28	28

Parametrics

Parameters / Models	LTC1703CG#PBF	LTC1703CG#TRPBF	LTC1703IG#PBF	LTC1703IG#TRPBF
Design Tools	LTspice Model	LTspice Model	LTspice Model	LTspice Model
Export Control	no	no	no	no
Features	VID, PolyPhase	VID, PolyPhase	VID, PolyPhase	VID, PolyPhase
Frequency, kHz	550	550	550	550
Integrated Inductor	no	no	no	no
Ishutdown, µA	30	30	30	30
Isupply, mA	2.2	2.2	2.2	2.2
Max Phases	2	2	2	2
Monolithic	no	no	no	no
Number of Outputs	1	1	1	1
Operating Temperature Range, °C	0 to 70	0 to 70	-40 to 85	-40 to 85
Output Current, A	25	25	25	25
Polyphase	yes	yes	yes	yes
Switch Current, A	25	25	25	25
Synchronous	yes	yes	yes	yes
Topology	Buck	Buck	Buck	Buck
Vin Max, V	7	7	7	7
Vin Min, V	3	3	3	3
Vout Max, V	2	2	2	2
Vout Min, V	0.9	0.9	0.9	0.9

Eco Plan

	LTC1703CG#PBF	LTC1703CG#TRPBF	LTC1703IG#PBF	LTC1703IG#TRPBF
RoHS	Compliant	Compliant	Compliant	Compliant

Design Notes

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Active Voltage Positioning Reduces Output Capacitors &mdash Design Solutions 10
PDF, 130 Kb, File published: Nov 1, 1999
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Design Solutions 10
November 1999
Active Voltage Positioning Reduces Output Capacitors
by Robert Sheehan
INTRODUCTION
Power supply performance, especially transient response,
is key to meeting todayвЂ™s demands for low voltage, high
current microprocessor power. In an effort to minimize
the voltage deviation during a load step, a technique that
has recently been coined вЂњactive voltage positioningвЂќ is
generating substantial interest and gaining popularity in
the portable computer market. The benefits include lower
peak-to-peak output voltage deviation for a given load
step, without having to increase the output filter capacitance. Alternatively, the output filter capacitance can be
reduced while maintaining the same peak-to-peak transient response.
BASIC PRINCIPLE
The term вЂњactive voltage positioningвЂќ (AVP) refers to
setting the power supply output voltage at a point that is
dependent on the load current. At minimum load, the
output voltage is set to a slightly higher than nominal level.
At full load, the output voltage is set to a slightly lower than
nominal level. Effectively, the DC load regulation is
degraded, but the load transient voltage deviation will be …
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2-Step Power Conversion: Portable Power for the Future &mdash Design Solutions 8
PDF, 119 Kb, File published: Apr 1, 1999
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Design Solutions 8
April 1999
2-Step Power Conversion:
Portable Power for the Future
As microprocessor operating voltages continue to
decrease, power conversion for CPU core power is
becoming a daunting challenge. A core power supply
must have fast transient response, good efficiency, and
low heat generation in the vicinity of the processor. These
factors will soon force a move away from 1-step power
conversion from battery or wall adapter to processor, to
2-step conversion where the CPU core power is obtained
from the 5V supply. While new to the portable arena,
distributed power systems using 5V as a bus voltage have
been used in large systems for many years. And although
it may not be absolutely necessary to adopt this architecture in portables today, the clock is ticking for the old
brute-force approach.
LetвЂ™s start with the biggest argument against 2-step
conversion: the perceived drop in efficiency and attendant heat generation in the 5V supply. Quick calculations may give a false impression that efficiency significantly
decreases. It does not! Later in this paper we will show
accurate calculations of efficiency for 2-step power conversion based on actual demo board measurements that
show overall efficiency numbers equal to 1-step high
efficiency converters. …
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2-Phase DC/DC Controller Reduces Capacitanceand Increases Battery Life in Portable Applications &mdash Design Solutions 9
PDF, 106 Kb, File published: Jun 1, 1999
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Design Solutions 9
June 1999
2-Phase DC/DC Controller Reduces Capacitance
and Increases Battery Life in Portable Applications
The LTCВ®1628 dual high efficiency DC/DC controller brings
the considerable benefits of 2-phase operation to portable
applications for the first time. Notebook computers, PDAs,
handheld terminals and automotive electronics will all
benefit from the lower input filtering requirement, reduced
electromagnetic interference (EMI) and increased efficiency associated with 2-phase operation. coming from the switches, greatly reducing the overlap
time where they add together (see Figure 1). The result is
a significant reduction in total RMS input current, which,
in turn, allows less expensive input capacitors to be used,
reduces shielding requirements for EMI and improves real
world operating efficiency.
Figure 2 compares the input waveforms for a representative 1-phase dual switching regulator to the new LTC1628
2-phase dual switching regulator. An actual measurement
of the RMS input current under these conditions shows
that 2-phase operation lowers the input current from
2.53ARMS to 1.55ARMS. Why the need for 2-phase operation? Before the LTC1628,
constant-frequency dual switching regulators operated
both channels in phase (i.e., 1-phase operation). This
means that both switches turned on at the same time, …
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LTC1702/LTC1703 Switching Regulator Controllers Set a New Standard for Transient Response &mdash DN206
PDF, 87 Kb, File published: May 2, 1999
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advertisement LTC1702/LTC1703 Switching Regulator Controllers Set a New
Standard for Transient Response вЂ“ Design Note 206
Dave Dwelley
The LTC В®1702 is the п¬Ѓrst in a new family of low voltage, high speed switching regulator controllers. It is
designed to operate from a standard 5V logic supply
and generate two lower voltage, high current regulated
outputs. Running at a п¬Ѓxed 550kHz switching frequency,
each side of the LTC1702 features a voltage feedback
architecture with a 25MHz gain-bandwidth op amp as the
feedback ampliп¬Ѓer, allowing loop crossover frequencies
in excess of 50kHz. Powerful onboard MOSFET drivers
allow the LTC1702 to drive large, high current external
MOSFETs efп¬Ѓciently at 550kHz. The high feedback loop
bandwidth maintains excellent transient response, and
the high switching frequency allows the use of small
external inductors and capacitors even as load currents
rise beyond 10A. The dual output LTC1702 is packaged
in a space-saving 24-pin narrow SSOP. consists of a modiп¬Ѓed LTC1702 with an internal 5-bit DAC
controlling the output voltage on side 1. The DAC conforms to the Intel Mobile VID speciп¬Ѓcations.
The LTC1702/LTC1703 each consist of two independent
switching regulator controllers in one package. Each
controller is designed to be wired as a voltage feedback,
synchronous step-down regulator, using two external …

Articles

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Active Voltage Positioning Saves Output Capacitors in Portable Computer Applications &mdash LT Journal
PDF, 169 Kb, File published: Feb 1, 2000
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DESIGN IDEAS Active Voltage Positioning Saves
Output Capacitors in Portable by John Seago
and Ajmal Godil
Computer Applications
Introduction
pp. 16вЂ“20) can take advantage of
active voltage positioning. Active voltage positioning is a technique that can be used to save cost
and space by reducing the number of
output capacitors required to meet a
microprocessorвЂ™s power supply
requirements. Total system cost and
required PCB space are important
aspects of todayвЂ™s portable equipment
designs, so decreasing the number of
large, expensive output capacitors is
worth some effort. Both the LTC1735/
LTC1736 current mode switching
regulator controllers (Linear Technology IX:1, February 1999, pp. 1, 3вЂ“5,
35) and the LTC1702/LTC1703
voltage mode controllers (Linear Technology IX:3, September 1999, Microprocessor Load Steps
Microprocessors frequently change
their load current requirement from
almost no load to maximum load current and back again very quickly. The …
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LTC1702/LTC1703 Switching Regulator Controllers Set a New Standard for Transient Response &mdash LT Journal
PDF, 192 Kb, File published: Sep 1, 1999
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DESIGN FEATURES LTC1702/LTC1703 Switching Regulator
Controllers Set a New Standard for
Transient Response
by Dave Dwelley
Introduction
The LTC1702 dual switching regulator controller uses a high switching
frequency and precision feedback circuitry to provide exceptional output
regulation and transient response
performance. Running at a fixed
550kHz switching frequency, each
side of the LTC1702 features a voltage feedback architecture using a
25MHz gain-bandwidth op amp as
the feedback amplifier, allowing loopcrossover frequencies in excess of
50kHz. Large onboard MOSFET drivers allow the LTC1702 to drive high
current external MOSFETs efficiently
at 550kHz and beyond. The high
switching frequency allows the use of
small external inductors and capacitors while maintaining excellent
output ripple and transient response,
even as load currents exceed the 10A
level. The dual-output LTC1702 is
packaged in a space-saving 24-pin
narrow SSOP, minimizing board space …

Model Line

Series: LTC1703 (4)

LTC1703CG#PBF LTC1703CG#TRPBF LTC1703IG#PBF LTC1703IG#TRPBF

Manufacturer's Classification

Power Management > Switching Regulator > Digitally Programmable Regulators