LTC3829IFE#TRPBF Linear Technology, LTC3829IFE#TRPBF Datasheet

IC REG CTLR 3CHAN SYNC 38TSSOP

LTC3829IFE#TRPBF

Manufacturer Part Number
LTC3829IFE#TRPBF
Description
IC REG CTLR 3CHAN SYNC 38TSSOP
Manufacturer
Linear Technology
Type
Step-Down (Buck)r
Datasheet

Specifications of LTC3829IFE#TRPBF

Internal Switch(s)
No
Synchronous Rectifier
Yes
Number Of Outputs
1
Voltage - Output
0.6 ~ 5 V
Frequency - Switching
250kHz ~ 770kHz
Voltage - Input
4.5 ~ 38 V
Operating Temperature
-40°C ~ 125°C
Mounting Type
Surface Mount
Package / Case
38-TSSOP Exposed Pad, 38-eTSSOP, 38-HTSSOP
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Current - Output
-
Power - Output
-

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
LTC3829IFE#TRPBFLTC3829IFE#PBF
Manufacturer:
LT
Quantity:
2 383
Company:
Part Number:
LTC3829IFE#TRPBF
Manufacturer:
LINEAR/凌特
Quantity:
20 000
applicaTions
Typical applicaTion
FeaTures
n
n
n
n
n
n
n
n
n
n
n
n
n
n
n
n
n
n
n
n
Optional Nonlinear Control for Fast Response
±0.75%, 0.6V Reference Accuracy
PWM, Stage Shedding™ or Burst Mode
High Efficiency: Up to 95%
R
Programmable DCR Temperature Compensation
Phase-Lockable Fixed Frequency: 250kHz to 770kHz
True Remote Sense Differential Amplifier
Programmable Active Voltage Positioning (AVP)
Triple N-Channel MOSFET Synchronous Drive
Wide V
V
V
Clock Input and Output for 6-Phase Operation
Adjustable Soft-Start or V
38-Pin (5mm × 7mm) QFN and FE Packages
Notebook and Palmtop Computers
Telecom Systems
Portable Instruments
DC Power Distribution Systems
OUT
OUT
SENSE
SW3 SW2 SW1
Range: 0.6V to 5V without Diffamp
Range: 0.6V to 3.3V with Diffamp
IN
or DCR Current Sensing
Range: 4.5V to 38V Operation
5k
680pF
4.7µF
0.1µF
20k
20k
100k
INTV
BOOST1
BOOST2
BOOST3
FREQ
I
TK/SS
SGND
DIFFOUT
V
DIFFN
DIFFP
TH
FB
OUT
CC
LTC3829
V
IN
Tracking
SENSE1
SENSE1
SENSE2
SENSE2
SENSE3
SENSE3
PGND
SW1
SW2
SW3
BG1
BG2
BG3
TG1
TG2
TG3
+
+
+
®
Operation
V
V
IN
IN
0.6µH
0.6µH
0.6µH
DC/DC Controller with Diffamp
0.002
0.002
0.002
+
DescripTion
The LTC
synchronous step-down DC/DC switching controller that
drives all N-channel synchronous power MOSFET stages.
A constant frequency current mode architecture allows a
phase-lockable frequency of up to 770kHz. Power loss and
noise due to ESR of the input capacitors are minimized by
operating the three controller output stages out of phase.
The LTC3829 can be configured for 6-phase operation,
has DCR temperature compensation, and output foldback
current limiting. This device features a precision 0.6V
reference and a power good indicator.
Light load efficiency is optimized by using a choice of
output Stage Shedding or Burst Mode operation. A dif-
ferential amplifier provides true remote sensing of the
output voltage at the point of load.
The LTC3829 is available in both low profile 38-pin 5mm
× 7mm QFN and Exposed Pad FE packages.
L, LT, LTC, LTM, Burst Mode, OPTI-LOOP , PolyPhase, Linear Technology, the Linear logo are
registered trademarks and Stage Shedding, No R
Corporation. All other trademarks are the property of their respective owners. Protected by
U.S. Patents, including 5481178, 5705919, 5929620, 6144194, 6177787, 6580258, 6498466,
6674274, 6611136.
+
3829 TA01
C
470µF
4V
V
1.2V
50A
OUT
4
OUT
22µF
35V
3
Synchronous Step-Down
V
6V TO 28V
®
IN
3-Phase, Single Output
3829 is a high performance 3-phase single output
100
95
90
85
80
75
70
65
60
55
50
0.1
V
V
IN
OUT
EFFICIENCY
= 12V
= 1.5V
LOAD CURRENT (A)
1
Efficiency
SENSE
POWER LOSS
are trademarks of Linear Technology
10
LTC3829
3829 TA01b
100
16
14
12
10
8
6
4
2
0

3829f

Related parts for LTC3829IFE#TRPBF

LTC3829IFE#TRPBF Summary of contents

Page 1

... The LTC3829 is available in both low profile 38-pin 5mm × 7mm QFN and Exposed Pad FE packages. L, LT, LTC, LTM, Burst Mode, OPTI-LOOP , PolyPhase, Linear Technology, the Linear logo are registered trademarks and Stage Shedding Corporation. All other trademarks are the property of their respective owners. Protected by U ...

Page 2

LTC3829 absoluTe MaxiMuM raTings Input Supply Voltage (V ) ......................... 40V to –0.3V IN Topside Driver Voltages (BOOSTn) ............ 46V to –0.3V Switch Voltage (SWn) ................................... 40V to –5V Boosted Driver Voltage (BOOSTn – SWn) .... 6V to –0.3V INTV ...

Page 3

... LTC3829EFE#PBF LTC3829EFE#TRPBF LTC3829IFE#PBF LTC3829IFE#TRPBF Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: ...

Page 4

LTC3829 elecTrical characTerisTics junction temperature range, otherwise specifications are at T SYMBOL PARAMETER TG Transition Time TG1,2,3 t Rise Time r TG1,2,3 t Fall Time f BG Transition Time BG1,2,3 t Rise Time r BG1,2,3 t Fall Time f TG/BG ...

Page 5

T SYMBOL PARAMETER Nonlinear Fast Transit Mode I Fast Transient Programmable Current V FAST AVP (Active Voltage Positioning) I Sink Current of AVP Pin SINK I Source Current of AVP Pin ...

Page 6

LTC3829 Typical perForMance characTerisTics Load Step-Up (0A to 75A, 75A/µs) (Nonlinear Operation) V OUT 100mV/DIV AC-COUPLED 75mV V SW1 10V/DIV V SW2 10V/DIV V SW3 10V/DIV 2µs/DIV Phase Shedding Transition V SW1 10V/DIV V SW2 10V/DIV V SW3 10V/DIV V ...

Page 7

Typical perForMance characTerisTics Quiescent Current vs Input Voltage without EXTV CC 5.5 5.3 5.1 4.9 4.7 4.5 4.3 4.1 3.9 3.7 3 INPUT VOLTAGE (V) 3829 G08 Maximum Current Sense Threshold vs Common Mode Voltage 90 ...

Page 8

LTC3829 Typical perForMance characTerisTics Regulated Feedback Voltage vs Temperature 0.604 0.602 0.600 0.598 0.596 0.594 0.592 –50 – 100 TEMPERATAURE (°C) 3829 G16 Oscillator Frequency vs Input Voltage 800 V FREQ 600 V FREQ 400 V ...

Page 9

FuncTions (UHF/FE) DIFFN (Pin 1/Pin 3): Negative Input of Remote Sensing Differential Amplifier. Connect this to the remote load ground pin. DIFFP (Pin 2/Pin 4): Positive Input of Remote Sensing Differential Amplifier. Connect this to the remote load positive ...

Page 10

LTC3829 pin FuncTions (UHF/FE) BOOST1, BOOST2, BOOST3 (Pins 33, 26, 19/Pins 35, 28, 21): Boosted Floating Driver Supplies. The (+) terminal of the bootstrap capacitors connect to these pins. These pins swing from a diode voltage drop below INTV to ...

Page 11

FuncTional DiagraM MODE PLLIN FREQ MODE/SYNC DETECT PLL-SYNC CLKOUT OSC – REV COMP – + IFAST IFAST I LIM SLOPE COMPENSATION INTV UVLO CC 1 51k SLOPE RECOVERY I THB ACTIVE CLAMP SLEEP ...

Page 12

LTC3829 operaTion (Refer to Functional Diagram) Main Control Loop The LTC3829 uses a constant frequency, current mode step-down architecture. During normal operation, each top MOSFET is turned on each cycle when the oscillator sets the RS latch, and turned off ...

Page 13

Functional Diagram) Light Load Current Operation (Burst Mode Operation, Stage Shedding or Continuous Conduction) The LTC3829 can be enabled to enter high efficiency Burst Mode operation, Stage Shedding mode or forced continuous conduction mode. To select forced ...

Page 14

LTC3829 operaTion (Refer to Functional Diagram) A phase-locked loop (PLL) is available on the LTC3829 to synchronize the internal oscillator to an external clock source that is connected to the PLLIN pin. The PLL loop filter network is integrated inside ...

Page 15

The Typical Application on the first page of this data sheet is a basic LTC3829 application circuit. The LTC3829 can be configured to use either DCR (inductor resistance) sens- ing or low value resistor sensing. The choice between ...

Page 16

LTC3829 applicaTions inForMaTion LTC3829 SGND OPTIONAL TEMP COMP NETWORK NTC peak sense voltage can be as low as 20mV. In addition, inductor ripple currents greater than 50% with operation up to 1MHz are becoming more ...

Page 17

V t • t ESL STEP ( ) ON OFF ESL = ∆ ...

Page 18

LTC3829 applicaTions inForMaTion A conservative value for T is 100°C. To scale the L(MAX) maximum inductor DCR to the desired sense resistor value, use the divider ratio: R SENSE EQUIV ( ) DCR MAX ...

Page 19

The NTC resistor has a negative temperature coefficient, meaning its value decreases as temperature rises. The V voltage, therefore, decreases as temperature in- ITEMP creases and in turn, the V SENSEMAX(ADJ) compensate the DCR temperature coefficient. The NTC ...

Page 20

LTC3829 applicaTions inForMaTion 10000 THERMISTOR RESISTANCE R = 100k O 1000 T = 25° 4334 FOR 25°C/100°C 100 R ITMP R = 20k 43. 100k NTC 1 –40 – ...

Page 21

Slope Compensation and Inductor Peak Current Slope compensation provides stability in constant frequen- cy current mode architectures by preventing sub-harmonic oscillation at high duty cycles accomplished internally by adding a compensating ramp to the inductor current ...

Page 22

LTC3829 applicaTions inForMaTion Power MOSFET and Schottky Diode (Optional) Selection At least two external power MOSFETs must be selected for each of the three output sections: One N-channel MOSFET for the top (main) switch and one or more N-channel MOSFET(s) ...

Page 23

N is the number of output stages, δ is the tem- perature dependency DS(ON) driver resistance (approximately 2Ω the drain potential and the change in drain potential in the particular ...

Page 24

LTC3829 applicaTions inForMaTion The Figure 10 graph shows that the peak RMS input current is reduced linearly, inversely proportional to the number N of stages used important to note that the efficiency loss is proportional to the input ...

Page 25

The emergence of very low ESR capacitors in small, surface mount packages makes very small physical implementa- tions possible. The ability to externally compensate the switching regulator loop using the I wider selection of output capacitor types. The ...

Page 26

LTC3829 applicaTions inForMaTion The final load slope is defined by the inductor current sense resistors and the two external resistors mentioned above. In summary, the load slope is:   R AVP R •    ...

Page 27

Nonlinear control is only enabled when V UV and OV window. It should be enabled only for forced continuous mode of operation. Once nonlinear control is enabled, the top gate of all chan- nels will turn on if: ...

Page 28

LTC3829 applicaTions inForMaTion The LTC3829 allows the user to program how its output ramps up and down by means of the TK/SS pins. Through these pins, the output can be set up to either coincidentally or ratiometrically track another supply’s ...

Page 29

INTV (LDO) and EXTV CC CC The LTC3829 features a true PMOS LDO that supplies power to INTV from the V supply. INTV CC IN drivers and much of the LTC3829’s internal circuitry. The LDO regulates the voltage ...

Page 30

LTC3829 applicaTions inForMaTion 4. EXTV connected to an output-derived boost network. CC For 3.3V and other low voltage regulators, efficiency gains can still be realized by connecting EXTV output-derived voltage that has been boosted to greater than 4.7V. For applications ...

Page 31

Fault Conditions: Current Limit and Current Foldback The LTC3829 includes current foldback to help limit load current when the output is shorted to ground. If the out- put falls below 50% of its nominal output level, then the ...

Page 32

LTC3829 applicaTions inForMaTion EXTERNAL OSCILLATOR Minimum On-Time Considerations Minimum on-time the smallest time duration ON(MIN) that the LTC3829 is capable of turning on the top MOSFET determined by internal timing delays and the gate charge ...

Page 33

Efficiency Considerations The percent efficiency of a switching regulator is equal to the output power divided by the input power times 100 often useful to analyze individual losses to determine what is limiting the efficiency and ...

Page 34

LTC3829 applicaTions inForMaTion Checking Transient Response The regulator loop response can be checked by looking at the load current transient response. Switching regulators take several cycles to respond to a step in DC (resistive) load current. When a load step ...

Page 35

Keep the SGND at one end of a printed circuit path thus preventing MOSFET currents from traveling under the IC. The INTV decoupling capacitor should be placed CC immediately adjacent to the IC between the INTV and ...

Page 36

LTC3829 applicaTions inForMaTion BOLD LINES INDICATE HIGH, SWITCHING CURRENTS. KEEP LINES TO A MINIMUM LENGTH SW1 R SENSE1 D1 L2 SW2 R SENSE2 D2 L3 SW3 R SENSE3 D3 Figure 17. ...

Page 37

Typical applicaTion IFAST RUN MODE FREQ ILIM PLLIN LTC3829 SENSE3 – SENSE3 + SENSE2 – SENSE2 + SENSE1 – SENSE1 +  3829f ...

Page 38

LTC3829 package DescripTion 5.50 0.05 4.10 0.05 3.00 REF APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED 5.00 0.10 PIN 1 TOP MARK (SEE NOTE 6) 7.00 0.10 NOTE: 1. DRAWING CONFORMS TO JEDEC PACKAGE OUTLINE M0-220 VARIATION WHKD ...

Page 39

... DRAWING NOT TO SCALE Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. FE Package 38-Lead Plastic TSSOP (4.4mm) ...

Page 40

... MSOP-16E, 3mm × 3mm QFN-16 OUT IN = 43ns, 4V ≤ V ON(MIN) ≤ 0.9V , SSOP-16 OUT IN = 43ns, 4V ≤ V ON(MIN) , MSOP-16E, 3mm × 3mm QFN-16 ≤ 0.9V OUT IN LT 0410 • PRINTED IN USA  LINEAR TECHNOLOGY CORPORATION 2010 ≤ 38V, IN ≤ 38V, IN 3829f ...

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