Datasheet Linear Technology LT3504

Manufacturer	Linear Technology
Series	LT3504

Quad 40V/1A Step-Down Switching Regulator with 100% Duty Cycle Operation

Datasheets

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PDF, 498 Kb, Language: en, File uploaded: Sep 18, 2017, Pages: 24
Quad 40V/1A Step-Down Switching Regulator with 100% Duty Cycle Operation

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Packaging

	LT3504EUFD#PBF	LT3504EUFD#TRPBF	LT3504IUFD#PBF	LT3504IUFD#TRPBF
N	1	2	3	4
Package	4x5 QFN-28 Package Outline Drawing	4x5 QFN-28 Package Outline Drawing	4x5 QFN-28 Package Outline Drawing	4x5 QFN-28 Package Outline Drawing
Package Code	UFD	UFD	UFD	UFD
Package Index	05-08-1712	05-08-1712	05-08-1712	05-08-1712
Pin Count	28	28	28	28

Parametrics

Parameters / Models	LT3504EUFD#PBF	LT3504EUFD#TRPBF	LT3504IUFD#PBF	LT3504IUFD#TRPBF
Architecture	Constant Frequency Current Mode	Constant Frequency Current Mode	Constant Frequency Current Mode	Constant Frequency Current Mode
Demo Boards	DC1207A	DC1207A	DC1207A	DC1207A
Design Tools	LTspice File	LTspice File	LTspice File	LTspice File
Export Control	no	no	no	no
Features	100% Duty Cycle, Resistor Set Frequency, External Synchronization, Anti-Phase Switching, Tracking	100% Duty Cycle, Resistor Set Frequency, External Synchronization, Anti-Phase Switching, Tracking	100% Duty Cycle, Resistor Set Frequency, External Synchronization, Anti-Phase Switching, Tracking	100% Duty Cycle, Resistor Set Frequency, External Synchronization, Anti-Phase Switching, Tracking
Frequency, kHz	2200	2200	2200	2200
Frequency Adjust Range	250kHz - 2.2MHz	250kHz - 2.2MHz	250kHz - 2.2MHz	250kHz - 2.2MHz
Frequency Sync Range	350kHz - 2.2MHz	350kHz - 2.2MHz	350kHz - 2.2MHz	350kHz - 2.2MHz
Integrated Inductor	no	no	no	no
Ishutdown, µA	0.01	0.01	0.01	0.01
Isupply, mA	2.7	2.7	2.7	2.7
Monolithic	yes	yes	yes	yes
Number of Outputs	4	4	4	4
Operating Temperature Range, °C	0 to 85	0 to 85	-40 to 85	-40 to 85
Output Current, A	1	1	1	1
Output Current 2, A	1	1	1	1
Output Current 3, A	1	1	1	1
Polyphase	no	no	no	no
Switch Current, A	1.75	1.75	1.75	1.75
Switch Current 2, A	1.75	1.75	1.75	1.75
Switch Current 3, A	1.75	1.75	1.75	1.75
Synchronous	no	no	no	no
Topology	Buck	Buck	Buck	Buck
Topology 1	Buck	Buck	Buck	Buck
Topology 2	Buck	Buck	Buck	Buck
Topology 3	Buck	Buck	Buck	Buck
Vin Max, V	40	40	40	40
Vin Min, V	3.2	3.2	3.2	3.2
Vout Max, V	40	40	40	40
Vout Max 2, V	40	40	40	40
Vout Max 3, V	40	40	40	40
Vout Maximum	Vin	Vin	Vin	Vin
Vout Min, V	0.8	0.8	0.8	0.8
Vout Min 2, V	0.8	0.8	0.8	0.8
Vout Min 3, V	0.8	0.8	0.8	0.8
Vref Accuracy Over Temp, %	2	2	2	2

Eco Plan

	LT3504EUFD#PBF	LT3504EUFD#TRPBF	LT3504IUFD#PBF	LT3504IUFD#TRPBF
RoHS	Compliant	Compliant	Compliant	Compliant

Articles

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Compact Quad Step-Down Regulator with 100% Duty Cycle Operation Withstands 180V Surges &mdash LT Journal
PDF, 2.9 Mb, File published: Apr 10, 2013
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Compact Quad Step-Down Regulator with 100% Duty Cycle
Operation Withstands 180V Surges
Jonathan Paolucci Automotive, industrial and distributed applications routinely subject step-down
DC/DC converters to a vast assortment of supply voltage transients. High voltage
power spikes and input voltage dips can destroy sensitive circuits and jeopardize
system reliability. To avoid damage, most applications rely on Tranzorbs or protection
circuits that use MOSFETs as pass elements to suppress input voltage transients.
If an N-channel MOSFET is used for this purpose, some means of providing gate
drive above the input rail is necessary to bias the MOSFET on. Generating this bias
is an undesirable complication that most engineers would prefer to avoid.
The LT3504 is a 4-channel monolithic
step-down regulator designed for 100%
duty cycle operation. Its unique architecture makes available a bias voltage,
which is easily adapted to an N-channel
protection scheme, allowing the LT3504
to operate continuously through overvoltage transients and dropouts down
to 3.2V. Among its many features, the
LT3504 includes output voltage tracking and sequencing, programmable frequency, programmable undervoltage
lockout, and a power good pin to indicate when all outputs are in regulation.
QUAD 1A STEP-DOWN REGULATOR Figure 1 shows the complete application
circuit for a 4-output, 1A step-down regulator operating over a 3.2V to 30V range.
Q1 provides surge protection to 180V.
An on-chip boost regulator generates VSUPPLY …

Model Line

Series: LT3504 (4)

LT3504EUFD#PBF LT3504EUFD#TRPBF LT3504IUFD#PBF LT3504IUFD#TRPBF

Manufacturer's Classification

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