NXP

MC34700

9.0 to 18 V, Quad Output, Integrated MOSFET Power Supply

Topology: Buck
Input Voltage (min.): 9.00 V
Input Voltage (max.): 18.00 V
Switching Frequency (min.): 760.00 kHz
Switching Frequency (max.): 840.00 kHz
Output 1: 1.25 V / 1.250 A
Output 2: 2.50 V / 1.250 A
Output 3: 3.30 V / 1.500 A

Original publication on 2008-04-01, revision 5.0

Description

The 34700 is a compact, high-efficiency power supply with on-chippower MOSFETs that features three step-down switching regulatorsand one low dropout linear regulator. The switching regulators utilizevoltage mode control with external compensation, allowing flexibility inoptimizing the performance of the 34700 for a given application.The 34700 is ideal for space constrained applications wheremultiple power rails are required and simplicity of design andimplementation of the power supply is necessary. Over-voltage,under-voltage, over-current, and over-temperature protectionfeatures ensure robust and reliable operation. Fixed switchingfrequency, internal soft-start, and internal power MOSFETs enablerapid power supply design and development.The 34700 is well suited for power supply designs in wide variety of applications, including set top boxes, cable modems, laser printers, fax machines, point-of-sale terminals, small appliances, telecom line cards, and DVD players.

Characteristics

  • Three switching regulators: 2 synchronous and 1 nonsynchronous• One low dropout linear regulator• Output current capability:• 1.5 A continuous on channel 1• 1.25 A continuous on channels 2 and 3• 400 mA continuous on channel 4• Internal power MOSFETs on all channels• Voltage feed-forward on channel 1• ±1.5% Output voltage accuracy on all channels• Cycle-by-cycle current limit and short-circuit protection• Fixed 800 kHz switching frequency• Internal soft-start• Over-voltage, under-voltage and over-temperatureprotection• Open-drain power-good output signal• Separate active-high enable input for each channel• Pb-free packaging designated by suffix code EP

Products

  Order Code SPEC Product series L
(µH)
IR
(A)
ISAT
(A)
RDC typ.
(mΩ)
RDC max.
(mΩ)
fres
(MHz)
Bauform Version Samples
7447789004 PDF WE-PD SMT Power Inductor 4.7 2.9 3.9 33 35 45 7332 Robust