Datasheet Linear Technology LTC3838-2

Manufacturer	Linear Technology
Series	LTC3838-2

Dual, Fast, Accurate Step-Down DC/DC Controller with External Reference Voltage and Dual Differential Output Sensing

Datasheets

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PDF, 968 Kb, Language: en, File uploaded: Sep 23, 2017, Pages: 56
Dual, Fast, Accurate Step-Down DC/DC Controller with External Reference Voltage and Dual Differential Output Sensing

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Packaging

	LTC3838EUHF-2#PBF	LTC3838EUHF-2#TRPBF	LTC3838IUHF-2#PBF	LTC3838IUHF-2#TRPBF
N	1	2	3	4
Package	5x7 QFN-38 Package Outline Drawing	5x7 QFN-38 Package Outline Drawing	5x7 QFN-38 Package Outline Drawing	5x7 QFN-38 Package Outline Drawing
Package Code	UHF	UHF	UHF	UHF
Package Index	05-08-1701	05-08-1701	05-08-1701	05-08-1701
Pin Count	38	38	38	38

Parametrics

Parameters / Models	LTC3838EUHF-2#PBF	LTC3838EUHF-2#TRPBF	LTC3838IUHF-2#PBF	LTC3838IUHF-2#TRPBF
Architecture	Controlled On-Time Valley Current Mode	Controlled On-Time Valley Current Mode	Controlled On-Time Valley Current Mode	Controlled On-Time Valley Current Mode
Demo Boards	DC1997A-B	DC1997A-B	DC1997A-B	DC1997A-B
Design Tools	LTspice File,LTpowerCAD Model	LTspice File,LTpowerCAD Model	LTspice File,LTpowerCAD Model	LTspice File,LTpowerCAD Model
Export Control	no	no	no	no
Features	Differential Remote Sense, External Synchronization, Resistor Set Frequency, DCR Current Sense, Power Good, Tracking	Differential Remote Sense, External Synchronization, Resistor Set Frequency, DCR Current Sense, Power Good, Tracking	Differential Remote Sense, External Synchronization, Resistor Set Frequency, DCR Current Sense, Power Good, Tracking	Differential Remote Sense, External Synchronization, Resistor Set Frequency, DCR Current Sense, Power Good, Tracking
Frequency, kHz	2000	2000	2000	2000
Frequency Adjust Range	200kHz to 2MHz	200kHz to 2MHz	200kHz to 2MHz	200kHz to 2MHz
Frequency Sync Range	200kHz to 2MHz	200kHz to 2MHz	200kHz to 2MHz	200kHz to 2MHz
Integrated Inductor	no	no	no	no
Ishutdown, µA	15	15	15	15
Isupply, mA	3	3	3	3
Max Phases	2	2	2	2
Monolithic	no	no	no	no
Number of Outputs	2	2	2	2
Operating Temperature Range, °C	0 to 85	0 to 85	-40 to 85	-40 to 85
Output Current, A	30	30	30	30
Output Current 2, A	30	30	30	30
Polyphase	yes	yes	yes	yes
Sense Resistor	Rsense, DCR	Rsense, DCR	Rsense, DCR	Rsense, DCR
Switch Current, A	30	30	30	30
Switch Current 2, A	30	30	30	30
Synchronous	yes	yes	yes	yes
Topology	Buck	Buck	Buck	Buck
Topology 1	Buck	Buck	Buck	Buck
Topology 2	Buck	Buck	Buck	Buck
Vin Max, V	38	38	38	38
Vin Min, V	4.5	4.5	4.5	4.5
Vout Max, V	5.5	5.5	5.5	5.5
Vout Maximum	5.5V	5.5V	5.5V	5.5V
Vout Min, V	0.6	0.6	0.6	0.6
Vout Min 2, V	0.6	0.6	0.6	0.6
Vref Accuracy Over Temp, %	0.67	0.67	0.67	0.67

Eco Plan

	LTC3838EUHF-2#PBF	LTC3838EUHF-2#TRPBF	LTC3838IUHF-2#PBF	LTC3838IUHF-2#TRPBF
RoHS	Compliant	Compliant	Compliant	Compliant

Application Notes

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Modeling and Loop Compensation Design of Switching Mode Power Supplies &mdash AN149
PDF, 1.4 Mb, File published: Mar 23, 2015
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Application Note 149
January 2015
Modeling and Loop Compensation Design of
Switching Mode Power Supplies
Henry J. Zhang
Introduction Identifying The Problem TodayвЂ™s electronic systems are becoming more and more
complex, with an increasing number of power rails and
supplies. To achieve optimum power solution density,
reliability and cost, often system designers need to design
their own power solutions, instead of just using commercial power supply bricks. Designing and optimizing high
performance switching mode power supplies is becoming
a more frequent and challenging task. A well-designed switching mode power supply (SMPS)
must be quiet, both electrically and acoustically. An undercompensated system may result in unstable operations.
Typical symptoms of an unstable power supply include:
audible noise from the magnetic components or ceramic
capacitors, jittering in the switching waveforms, oscillation
of output voltage, overheating of power FETs and so on. Power supply loop compensation design is usually
viewed as a difficult task, especially for inexperienced
supply designers. Practical compensation design typically
involves numerous iterations on the value adjustment
of the compensation components. This is not only time
consuming, but is also inaccurate in a complicated
system whose supply bandwidth and stability margin …

Articles

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Dual, Fast, Step-Down Controller's External Reference Input Enables Dynamic Voltage Scaling from 0.4V to 5.5V and 0.3% Total Combined Regulation Accuracy &mdash LT Journal
PDF, 2.8 Mb, File published: Apr 10, 2013
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design features Dual, Fast, Step-Down ControllerвЂ™s External Reference Input
Enables Dynamic Voltage Scaling from 0.4V to 5.5V and
0.3% Total Combined Regulation Accuracy
Shuo Chen and Terry Groom Low voltage, high current
systems require accurate
differential regulation. It is
not uncommon for power
supply rails at or below
0.9V to demand 25A or
more, with fast transients
that look like intermittent
electrical shorts to the
power supply rail. Such
systems typically require
power supply regulation
accuracy of less than 1%
regulated DC and 3% in the
face of input transients.
Increasingly, core processors and other
large scale digital ICs (such as ASICs and
FPGAs) require dynamic voltage scalingвЂ”either multiple fixed levels, or a
continuously adjusted reference voltage
using a servo loopвЂ”to deliver power …

Model Line

Series: LTC3838-2 (4)

LTC3838EUHF-2#PBF LTC3838EUHF-2#TRPBF LTC3838IUHF-2#PBF LTC3838IUHF-2#TRPBF

Manufacturer's Classification

Power Management > Switching Regulator > Step-Down (Buck) Regulators > Multiple Output Buck | External Power Switch Buck Controllers