QM series; TDK’s ground-up revisit of modular PSU concept
TDK notes that these concerns came out strongly from user surveys; those showed the needs for very low levels of leakage, and for low noise – from all sources including moving air, fan noise and conducted hum and vibration. Not only is the noise undesirable but high volumes of air moved means issues with dust and contamination. TDK has measured the unit as having the lowest audible noise in its sector.
As with prior designs, the QM will consist of a chassis with front-end, into which the company will place selected units from a stock of output modules, to meet exact user requirements. The first chassis introduced accepts seven such modules; later introductions will host five and eight. QM is presented as the first 1200W to 1500W rated modular series to have full MoPPs (means of patient protection) isolation; with both medical and industrial safety certifications, the QM is suitable for a wide range of applications, including BF rated medical equipment, test and measurement, broadcast, communications and renewable energy applications.
Product definition is made using an online configurator, giving an optimised module selection with a choice of signals, leakage current and standby voltages. Once the desired output voltages and currents have been entered, the configurator will automatically produce a unique 8-digit code for easy order placement.
With a wide range 90-264Vac, 47-440 Hz input the QM can deliver 1200W; and 1500W with a 150-264Vac input. Up to 16 outputs can be provided, with voltages ranging from 2.8V to 52.8V, with additional higher voltages later. Module power ratings start with a low power 35W, with single or dual outputs, to a 1200W single output. The units will operate in ambient temperatures of -20 to +70°C, derating output power and output current by 2.5% per °C above 50°C. Overall case dimensions are a compact 176 x 63.3 x 270mm (W x H x D), and the weight is between 2.6 and 3.1kg, depending on the module configuration. The QM is covered by a seven-year warranty; the company is confident that it has specified components, especially electrolytic capacitors, to meet this pledge.
A PMBus option (not using a module slot) can be added to monitor the supply; digital control is not offered at this stage, and the basic control loop of the supply is analogue.
An optional standby/signal module is available with a choice of one or two standby voltages (5V and 12V at up to 2A). It also contains unit inhibit or unit enable, plus an AC Good signal. All the output modules are fitted with module good, module inhibit signals and remote sense as standard.
The QM operating efficiency is as high as 91%, reducing internal heat loss, allowing the use of low speed cooling fans. This reduces audible noise for an enhanced patient/user experience to just 44.3 dBA at room temperature and 45.3 dBA at 50°C – measured in accordance with BS EN ISO 3744:2010.
The units are certified to IEC/EN/UL/CSA 60601-1, ANSI/AAMI ES 60601-1, IEC/EN/UL/CSA 60950-1 and designed to meet IEC/EN61010-1 with CE marking for the Low Voltage and RoHS2 Directives. With an input to output isolation of 4,000Vac (2 x MoPPs), 1,500Vac input to ground (1 x MoPP) and 1,500Vac (1 x MoPP) output to ground, the series can be used in BF rated medical equipment. The QM has a maximum earth leakage current of 300µA, while still complying with the EN61000-6-3:2007 and EN60601-1-2:2015 (curve B conducted and radiated) emission standards. The units also meet the EN60601-1-2 and EN61000-6-2 immunity standards and are designed and manufactured under the control of ISO9001 and ISO13485 (including risk management).