LTC1929 Series

2-Phase, High Efficiency, Synchronous Step-Down Switching Regulators

Catalog

2-Phase, High Efficiency, Synchronous Step-Down Switching Regulators

Part	Operating Temperature [Max]	Operating Temperature [Min]	Voltage - Supply (Vcc/Vdd) [Min]	Voltage - Supply (Vcc/Vdd) [Max]	Number of Outputs	Output Type	Control Features	Package / Case [custom]	Package / Case	Package / Case [custom]	Duty Cycle (Max) [Max]	Mounting Type	Output Configuration	Topology	Function	Output Phases	Supplier Device Package
Analog Devices LTC1929IG-PG#PBF	85 °C	-40 °C	4 V	36 V	2	Transistor Driver	Enable Power Good Soft Start	0.209 in	28-SSOP	5.3 mm	99.5 %	Surface Mount	Positive	Buck	Step-Down	2	28-SSOP
Analog Devices LTC1929CG-PG#TRPBF	85 C	0 °C	4 V	36 V	2	Transistor Driver	Enable Power Good Soft Start	0.209 in	28-SSOP	5.3 mm	99.5 %	Surface Mount	Positive	Buck	Step-Down	2	28-SSOP
Analog Devices LTC1929CG#TRPBF	85 C	0 °C	4 V	36 V	2	Transistor Driver	Enable Power Good Soft Start	0.209 in	28-SSOP	5.3 mm	99.5 %	Surface Mount	Positive	Buck	Step-Down	2	28-SSOP

Catalog

2-Phase, High Efficiency, Synchronous Step-Down Switching Regulators

Key Features

• 2-Phase Single Output Controller

• Reduces Required Input Capacitance and Power Supply Induced Noise

• Current Mode Control Ensures Current Sharing

• Phase-Lockable Fixed Frequency: 150kHz to 300kHz

• True Remote Sensing Differential Amplifier

• OPTI-LOOP™Compensation Improves Transient Response

• ±1% Output Voltage Accuracy

• Wide VINRange: 4V to 36V Operation

• Very Low Dropout Operation: 99% Duty Cycle

• Adjustable Soft-Start Current Ramping

• Internal Current Foldback

• Short-Circuit Shutdown Timer with Defeat Option

• Overvoltage Soft-Latch Eliminates Nuisance Trips

• Available in 28-Lead SSOP Package

Description

The LTC1929/LTC1929-PG are 2-phase, single output, synchronous step-down current mode switching regulator controllers that drive N-channel external power MOSFET stages in a phase-lockable fixed frequency architecture. The 2-phase controllers drive their two output stages out of phase at frequencies up to 300kHz to minimize the RMS ripple currents in both input and output capacitors. The 2-phase technique effectively multiplies the fundamental frequency by two, improving transient response while operating each channel at an optimum frequency for efficiency. Thermal design is also simplified.An internal differential amplifier provides true remote sensing of the regulated supply’s positive and negative output terminals as required by high current applications.The RUN/SS pin provides soft-start and a defeatable, timed, latched short-circuit shutdown to shut down both channels. Internal foldback current limit provides protection for the external synchronous MOSFETs in the event of an output fault. OPTI-LOOP compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values.ApplicationsDesktop ComputersInternet/Network ServersLarge Memory ArraysDC Power Distribution Systems