December 13, 2007

Module ICs for DC/DC Converters
MPM Series Developed
Footprint reduced to 1/4 and number of parts to 1/2 through incorporation of external parts

Sanken Electric Co., Ltd. has developed and started shipping samples of two types of MPM Series module ICs for step-down DC/DC converters that incorporate a flywheel diode, a choke coil, and capacitors, all normally external parts, in a single resin-encapsulated package, the MPM-2801S (1.5 A output current) and the MPM-2802Q (3.0A output current). The tax-excluded unit price is 1500 yen for the MPM-2801S and 2500 yen for the MPM-2802Q.

The ICs will ship in volume during Q2, CY08, with initial monthly production of 50k units, to be ramped up to 300k units by the end of CY08.

1. Development Background and Product Overview

As the performance of digital ICs such as microcontrollers, DSPs, and ASICs used in electronic devices such as personal computers and measuring equipment increases, such ICs use sharply varying load currents. Further, owing to the influence of voltage drops caused by the wiring of the DC/DC converter circuit between the input power supply and these digital ICs, the input voltage to the IC fluctuates, which may cause the IC to malfunction.

In recent years, these problems have been avoided through the use of method called point of load (POL), whereby the DC/DC converter circuit is placed as close as possible to the input power supply pin(s) of the digital IC.

However, a separate POL power supply is required for each of the several digital ICs mounted in the electronic equipment, and also a single digital IC may require several different voltage levels, resulting in drawbacks, namely an increase in the number of parts, circuit design man-hours and management man-hours, and also use of a larger percentage of the board area for POL power supplies.

Thus, Sanken Electric's answer is to use its own proprietary regulator ICs and full-mold packages to develop the MPM Series of module ICs for step-down DC/DC converters, incorporating in a single resin-encapsulated package not only a control circuit and a MOSFET but also a flywheel diode, a choke coil, and input/output capacitors, which were all conventionally connected externally to a regulator IC.

By building in these external parts, a reduction in mounting area to approximately 25% that of a conventional DC/DC converter circuit assembled on a board and a 50% reduction in the number of parts are achieved. In addition, as module ICs incorporates the external parts, the ICs contribute to a reduction in the number of man-hours for circuit design and parts evaluation, while also contributing to reduction in man-hours of parts procurement and management.

Moreover, these ICs achieve low noise as current-loop-generated noise that occurs in board-type ICs with long wiring distances is suppressed by their resin-encapsulated packages.

The MPM Series boasts a wide input voltage range from 4.75 to 16 V. As a result, it can be driven directly from 5 V and 12 V power supplies and is compatible with the input voltages of 1.0 to 5.0 V digital ICs.

2. Applications
(1)  Information and office automation equipment such as PCs, servers, digital multi-function devices, and plain paper copiers
(2) Factory automation and industrial equipment such as sequencers, measuring devices, oscilloscopes, etc.
3. Features
(1)  Module IC for resin-encapsulated type step-down DC/DC converter incorporating external parts
<1>  Resin-encapsulated type incorporating in a single package a flywheel diode, a choke coil, and input/output capacitors required to configure a DC/DC converter circuit
<2> Compared with board type, mounting area reduced to approx. 25%, and number of parts roughly halved
  • MPM-2801S.SO16 pin (Resin part dimensions: 20×6.3×3.6, mm)
  • MPM-2802Q…QFN25 pin(Resin part dimensions: 16.5×12×4, mm; with backside heat slug)
<3> In the module IC, the parts are connected to a bare chip with shorter wires than those used for connecting the external parts to the separate IC, so the wiring distances of parts are kept short, resulting in low noise.
(2) Wide input voltage range
The wide input voltage range (4.75 to 16 V) enables direct driving from 5 V and 12 V power supplies.
(3) Compatible with digital ICs having various power supply voltages
Settable to various output voltages (1.0, 1.2, 1.5, 1.8, 2.0, 2.5, 3.3, 5.0V, etc.) through an external part value.
(4) Various built-in protection functions
  • Drooping type overcurrent protection function
  • Overheat protection function
  • Under voltage lockout function
(5) Included functions
  • Soft start function
  • On/off function
4. Specifications
Parameter MPM-2801S MPM-2802Q Unit
Input voltage range 4.75 to 16 V
Output current 1.5 3.0 A
Output voltage range Externally settable to 1.0, 1.2, 1.5, 1.8, 2.0, 2.5, 3.3, 5.0, etc. V
Operating temperature range -20 to +85 °C
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