100V, 250mA, surface mount, high speed switching diode

Probe domestic switch needle KG-300K needle head diameter is 3.0mm normally open switch needle

This paper analyzes the circuit design and component application characteristics of DC output 48V/70A and 350V/10A 3500W and 48V/112A and 350V/17A 6000W high-end switching power supply, and puts forward the problem to be analyzed.

1 Introduction

In July 2001, a power technology enthusiast sent two high-end power supplies that were alleged to be “military top-secret”. I hope that I can make a special anatomy and in-depth analysis to digest and absorb its advanced technology.

The nameplate on the power iron casing indicates that it is a dedicated power source for IBM's "Bulk" large ship.

One is a long-type communication power supply with a DC output of 48V/70A, length × width × height = 70cm × 22cm × 12cm, and the weight is about 14kg. The grid input three-phase 380 ~ 415V (current 13A), can also reduce the input 200 ~ 240V (current 24A), frequency 50 ~ 60Hz. This power supply is equipped with an electric fan to force air cooling, and a three-phase high-voltage large switch is also installed on the outer casing. The grid input is first filtered by a large shielded box.

The other is a short-type special power supply with a DC output of 350V/10A. The length × width × height = 40cm × 30cm × 8cm, weight about 10kg, no forced air cooling, and the radiator is also short. The nameplate on the iron shell is marked as three-phase input of the power grid. There are three input ranges: 200~240V, 380~415V, 460~480V. IIN = 25A (MAX) at low voltage; its output DC is 350V / 12.5A (MAX). The grid frequency is 50 to 60 Hz.

2 3500W power supply anatomy

The first step in the anatomy is to desolder the high-power components on the two (two) power boards. There are three types:

1) The heaviest large magnetic component main power transformer and Boost energy storage inductor, iron powder core magnetic ring inductance 5; 2) large MOSFET, IGBT power switch tube module, and two grid rectifier modules P425; Large-scale high-voltage aluminum electrolytic capacitors 940μF/450V4 only, 220μF/450V2 only, and multiple CBB high-frequency, high-voltage, non-inductive, non-polar polypropylene large capacitors, are high-quality surge absorber components.

2.1 IR Power Devices

First of all, what surprised me unexpectedly is that the MOSFETs and IGBT modules, which are trademarks of IR Company, are all replaced by fake code names, which are not found in the IR company's thick product manual.

1) A module with a diode connected to the IGBT is labeled as “F530 (9604)”, “F826 (9615)”, “F1670 (9726)”, “F4702 (9845)”, etc.

2) Judging from the circuit is a module with a diode in the MOSFET, labeled "M4005 (6315)", "M4427 (9624)", "M3422 (9611)", etc.

3) It is judged by the circuit that it is a module of two MOSFETs (half bridge double pipe), and is labeled "M5220 (9708)", "M5662 (9726)", "M3419 (9603)", "M6768 (9814)", and the like.

This special case has never been seen on the market, each weighing nearly 100g of MOSFET large modules. There are 4 power supplies for each power supply, and the thickness of the copper block on the top of the heat dissipation is 6mm, length × width = 9.2cm × 2cm. The 48V power supply has a burst.

4) The main chip on the PFC control board is labeled “53H1747”, and the four power supplies are the same. It should be UC3854. I first brought 8 to 9 MOSFETs and IGBTs of IR products that were desoldered and brought them to the IR Shenzhen branch for technical inquiry and identification. The answer is “military top secret” products, non-industrial civilian products, so there is no manual. According to the analysis of 3500W power supply, the reverse withstand voltage of the MOSFET should be 500V ~ 600V, and the working current is 30A ~ 40A. Because the IR agent confirmed the large-scale high-frequency switch tube used on these two high-power power supply boards, it is a high-end product specially made for military equipment, and used the fake code for confidentiality. Therefore, it is worthwhile to make in-depth anatomy, comprehensive measurement and special analysis of the two 3500W power supplies. Then I checked the MOSFET and IGBT module sidewall trademarks on several open-cap power motherboards at the supplier several times, and recorded the main symbols in detail, only to find the special MOSFET of IR company in Mexico (MADEINMEXICO). The following important tags:

——Where the “82-5039+” is marked on the bottom layer, no matter how the code changes, it is a half-bridge double-tube MOSFET, such as “M7471 (9846)”, “M3937 (9613)”, “M3438 (9602)” , "M5706 (9732)", "M3467 (9602)";

——Where the lowest layer is marked as “82-6252+”, no matter how the fake code is changed, it is a single-tube MOSFET plus one diode, such as “M7453(9845)”, “M4045(9616)”, “M3721(9609) ", M5394 (9714)", "M3161 (9547)", "M3453 (9602)", etc.

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