LTC3729EG

Buck: Yes
Inverting: No
Doubler: No
Divider: No
Cuk: No
Isolated: No
PWM Type: Current Mode
Number of Outputs: 1
Operating Temperature: -40°C ~ 85°C
Packaging: Tube
Boost: No
Flyback: No
Duty Cycle: 99.5%
Manufacturer: Linear Technology
Series: PolyPhase®
Voltage - Supply: 4 V ~ 36 V
Package / Case: 28-SSOP (0.209", 5.30mm Width)
Frequency - Max: 590kHz


Features:

 Wide VIN Range: 4V to 36V Operation
Reduces Required Input Capacitance and Power Supply Induced Noise
±1% Output Voltage Accuracy
Phase-Lockable Fixed Frequency: 250kHz to 550kHz
True Remote Sensing Differential Amplifier
 PolyPhaseTM Extends from Two to Twelve Phases
 Reduces the Size and Value of Inductors
Current Mode Control Ensures Current Sharing
1.1MHz Effective Switching Frequency (2-Phase)
OPTI-LOOP® Compensation Reduces COUT
Power Good Output Voltage Indicator
Very Low Dropout Operation: 99% Duty Cycle
Adjustable Soft-Start Current Ramping
Internal Current Foldback Plus Shutdown Timer
Overvoltage Soft-Latch Eliminates Nuisance Trips
Available in 5mm ´ 5mm QFN and 28-Lead SSOP Packages

Application

 Desktop Computers/Servers
 Large Memory Arrays
DC Power Distribution Systems


Pinout




Specifications

Input Supply Voltage (V_IN).........................36V to 0.3V
Topside Driver Voltages (BOOST1,2) .........42V to 0.3V
Switch Voltage (SW1, 2) .............................36V to 5 V
SENSE1^+, SENSE2 ⁺, SENSE1,
SENSE2 Voltages ........................ (1.1)INTV^_CC to 0.3V
EAIN, V_OS+, V_OS , EXTV_CC, INTV_CC,
RUN/SS, PGOOD Voltages ...........................7V to 0.3V
Boosted Driver Voltage (BOOST-SW) ..........7V to 0.3V
PLLFLTR, PLLIN, CLKOUT, PHASMD,
V_DIFFOUT V_oltages ................................ INTVCC to 0.3V
I_TH Voltage ................................................2.7V to 0.3V
Peak Output Current <1ms(TGL1,2, BG1,2) ................ 5A
INTVCC RMS Output Current ................................ 50mA
Operating Ambient Temperature
Range (Note 6) ................................... 40°C to 85°C
Junction Temperature (Note 2) ............................. 125°C
Storage Temperature Range ................. 65°C to 150°C
Lead Temperature (Soldering, 10 sec)
(G Package Only) .................................................. 300°C


Description

   The LTC®3729 is a multiple phase, synchronous stepdown current mode switching regulator controller that drives N-channel external power MOSFET stages in a phase-lockable fixed frequency architecture. The PolyPhase controller drives its two output stages out of phase at frequencies up to 550kHz to minimize the RMS ripple currents in both input and output capacitors. The output clock signal allows expansion for up to 12 evenly phased controllers for systems requiring 15A to 200A of output current.  

  The multiple phase LTC3729 technique effectively multiplies the fundamental frequency by the number of channels used, improving transient response while operating each channel at an optimum frequency for efficiency.

   Thermal design of LTC3729 is also simplified. An internal differential amplifier provides true remote sensing of the regulated supply's positive and negative output terminals as required for high current applications. A RUN/SS pin provides both soft-start and optional timed, short-circuit shutdown. Current foldback limits MOSFET dissipation during short-circuit conditions when the overcurrent latchoff is disabled. OPTI-LOOP compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The LTC3729 includes a power good output pin that indicates when the output is within ±7.5% of the designed set point.
 

Parameters:

Technical/Catalog Information	LTC3729EG
Vendor	Linear Technology
Category	Integrated Circuits (ICs)
Type	Step-Down (Buck)
Number of Outputs	1
Voltage - Input	4 ~ 36 V
Voltage - Output	0.8 ~ 5 V
Current - Output	5A
Power - Output	-
Package / Case	28-SSOP
Packaging	Tube
Internal Switch(s)	No
Synchronous	Yes
Rds (On)	-
Operating Temperature	-40°C ~ 85°C
Frequency - Switching	1.1MHz
Drawing Number	161; 05-08-1640; G; 16
Lead Free Status	Contains Lead
RoHS Status	RoHS Non-Compliant
Other Names	LTC3729EG LTC3729EG