Texas Instruments Incorporated introduced two new triple output plug-in power solutions that provide three logic level voltages as low as 1.2V, an industry first. The modules are designed to provide three regulated low-voltage outputs for mixed logic applications, such as DSPs, ASICs and microprocessors. Both triple output modules have a 50 percent smaller footprint than conventional single output modules, reducing board space and costs.

In addition to saving board space, the PT4820 and PT4850 ease design and speed time to market with internal sequencing of all three outputs. The sequencing meets the power up and power down sequencing requirements of TI's latest DSPs.

The isolated 35 Watt (W) PT4820 and the 75W PT4850 each operate from a 48 volt (V) input and can provide combinations of 5V, 3.3V, 2.5V, 1.8V, 1.5V, or 1.2V to power various digital applications including new DSPs, ASICs and microprocessors requiring 1.5V or 1.2V core voltages.

As part of TI's Excaliburý series, the PT4820 and PT4850 are available in surface-mount, vertical through-hole or horizontal through-hole styles and offer industry-leading features including:

• Three independently regulated output voltages -- choose from 5V, 3.3V, 2.5V, 1.8V, 1.5V, or 1.2V
• Internal sequencing -- supports latest DSP requirements
• Output currents of 8A/6A/6A (PT4820) and 15A/10A/10A (PT4850)
• Operates from standard 48V telecom central office bus (36V to 75V) 1500V input-output isolation
• Innovative, space-saving Excaliburý package for better thermal management and flexible mounting options -- no heat sinks required
• Industry-standard protection features, including short-circuit (all outputs), current limit, over-temperature, over-voltage and under-voltage lockout
• Dual inhibit (on/off)
• UL, CSA, IEC, and VDE approvals

More information at www.ti.com.

It might seem that there's no big deal about an introduction of triple output converters except that these are the first ones that provide three logic level voltages. There are other triple DC-DC converters but they provide 5V and ý12V or ý15V. This is the first converter that provides three logic level voltages.

What that does for the designer is to reduce time to market and reduce board space. Typically designers of equipment for the telecomm market particularly Central Office, Networking, and Wide Area Networks, will find this product attractive. It operates from standard telecomm input, 36V to 72V.

You may wonder why TI chose to introduce this converter now. The time is right because of the increased use of DSPs and other large scale ICs that have dual voltage requirements. Designers may now stop tearing their hair out because every IC they put on their board has requirement for different voltages. That means there are requirements for multiple voltages - especially low voltages. If designers start allocating space on their PCB for a different converter for every voltage that they need, then half of their board would be populated with DC-DC voltage converters. This IC can save you precious real-estate that would be lost if you used single converters.

Another difficulty encountered by designers occurs because the market is in transition from 5V to 3.3V power. Depending on the generation the designers choose they might need 3.3V for I/O, and a core voltage 2.5V if it's last generation ICs, or they may choose 1.5V or 1.8V if they use the current generation. So the system designer has to wrestle with all of these - he needs 3.3V, 2.5V, 1.8V or even 1.5V. This is a product that allows the designer to buy one module, put it on his board and provide him with whatever three logic outputs that he needs. The first output can be either 5V or 3.3V and the other two outputs can be from 2.5V down to 1.2V.

There is a maximum amperage for both the 4820 and 4850, however TI thought to make it flexible. The 4820 is designed for 35W, so you have to calculate the output volts times the amps and add all three together. For example, the first output of the 4820 is rated at 8 amps and the next two outputs are rated at 6A each. So, maybe you need 8A on the 3.3V and on the 1.5V you don't need all 4A. Although each of the outputs has a current rating there also is an overall power rating. And it's the same for the 75W on the 4850. The total current from all three outputs is 25A. Output 1 is rated at 15A, output 2 and 3 are rated at 10A each.

TI didn't stop there. In these modules the company included all the power up and power down sequencing for the parts. Therefore, if you are designing with three different voltages all three start up the same until they reach the lowest voltage before it stabilizes. Imagine three voltages looking like one line until it reaches 1.8V, then the 1.8V peels off while the other two voltages continue to rise until you get to the second voltage which might be 2.5V and that peels off until you get to 3.3V, which then stabilizes. That's difficult to do if the designer chooses to use 3 different modules to provide these three different voltages. It requires the designer to create circuitry to monitor the voltages and then come back and create some control circuitry to turn these parts on, at the same time. And that means you have to find three parts that have the same turn on characteristics, because different DC-DC converters have different turn-on characteristics depending on how the supplier has designed the startup circuitry. It's one less thing the designer has to worry about.

Samples of the PT4820 and PT4850 are available now with volume production planned for May. Planned pricing in quantities of 1,000 is $65 for the PT4820 series and $97 for the PT4850 series.

Data sheets and more information available