16:1 input range for rugged railway dc-dc converter

Update: August 19, 2021
16:1 input range for rugged railway dc-dc converter

The series is suited for all kinds of voltage parameters in different regions because of its ultra-wide input voltage,” according to the company. “Since rail traffic will be exposed to a harsh environment for a long time, this power converter has been certified to EN 50155, EN 61373 and EN 45545-2 standards.”

Called EC7BW18-xxxxx-ECRT, different versions offer different output voltages: 5, 12, 15, ±12, ±15 or ±24V are available (see table below). Depending on version, efficiency can be as high as 88%.

The ECRT suffix indicates a chassis-mount baseplate-cooled enclosure, which is 113 x 59 x 22mm. There is also a chassis and DIN-mount type (EDRT) where 22mm increases to 36mm.

All versions have a remote on-off connection, and single output versions include a control to trim the output across -20% to +15%.

Features include in-rush current limiting, input EMI filtering and an internal hold-up circuit. Regarding hold-up, the company tols Electronics Weekly: “If the input voltage is above 24V, the voltage supply can satisfy the Class 2. However, if the input voltage is above 48V, the voltage supply can satisfy Class 3”.

“Internal EMI filter reduces an adequate level of radiated emission and offers protection against interference from electrical and electronic devices on the railway rolling stock,” said the company.

Operation is across -40°C to 100°C, with linear derating above 67°C for the 5V version, 74°C for 12V and ±12V, and 76°C for the others (0.1m/s natural convection (20ft/min)).

Protections include: under-voltage lock-out (UVLO), output over-current, output over-voltage, over-temperature, and continuous short-circuit.

Railway applications are foreseen operating from nominal supplies of 24V, 36V, 48V, 72V, 96V or 110V, as well as for distributed power architectures, telecommunications, battery operated equipment and industrial use.

Part Output Max
output
No load
input
Efficiency
EC7BW18-72S05-ECRT 5V 4A 8mA 84%
EC7BW18-72S12-ECRT 12V 1.67A 10mA 87
EC7BW18-72S15-ECRT 15V 1.33A 10mA 88
EC7BW18-72D12-ECRT ±12V ±0.833A 10mA 87
EC7BW18-72D15-ECRT ±15V ±0.667A 10mA 88
EC7BW18-72D24-ECRT ±24V ±0.417A 10mA 88

In each case, there are different types with similar specs

  • -ECRT enclosed chassis-mount railway turn-key
  • -EDRT enclosed DIN rail and chassis-mount railway turn-key
  • -ECRTP as above with protective coating on certain components
  • -EDRTP as above with protective coating on certain components

In all cases, input range is 10 to 160Vdc, and input-output isolation is 3kVac – insulation meets UL62368-1 2nd (reinforced).

THe product page is here, and the application note here