TDK-Lambda Single, Bipolar and Triple Output Switching Power Supplies for Audio Projects

Construction information for DIY projects, including the MS Mid Side Matrix, Elliptic Equalizer, Mastering Console, Phono Transfer System, Insert Switcher and the Dual Class-A Amplifier. You can post your baby pictures here.
Post Reply
User avatar
mediatechnology
Posts: 3659
Joined: Sat Aug 11, 2007 2:34 pm
Location: Oak Cliff, Texas
Contact:

TDK-Lambda Single, Bipolar and Triple Output Switching Power Supplies for Audio Projects

Post by mediatechnology » Tue Mar 20, 2018 5:00 pm

I had a chance to test the TDK-Lambda 35W 5V 3A, +/-15V 650 mA switching supply.

TDK-Lambda CUT35-5FF Rating: Excellent

Mouser CUT35-5FF product page: https://www.mouser.com/ProductDetail/TD ... TIWQ%3d%3d
TDK CUT35 datasheet: https://www.mouser.com/ds/2/400/cut35-1101382.pdf
Mouser Project Manager for TDK CUT355FF power supply and mating connectors/pins: https://www.mouser.com/ProjectManager/P ... 65b59a493a

Image
TDK-Lambda CUT35-5FF 5V 3A +/-15V 0.65A Triple-output Power Supply

The CUT35 is a mixture of TH and SMT. The 8 pin DIP switcher ICs appear to be a Lambda proprietary part.

Image
TDK-Lambda CUT35-5FF 5V 3A +/-15V 0.65A Triple-output Power Supply

Note that there are dangerous potentially lethal line voltages on the primary side of this supply. Use caution when handling and bench-testing.

The CUT35-5FF is small measuring about 2" by 4".
One unique feature is that the bipolar output and 5V output are isolated and do not share a common ground.

The unloaded outputs measure almost exactly on-target.
The 5V is adjustable.

A minimum load is not required for start-up but it was found that a +/-15V (30V) pre-load current of 15 mA was required for low-noise operation.
If the CUT35 is started without pre-load and the load then added it remains somewhat noisy with sawtooth ripple in the 10s of millivolts.
With the 15 mA pre-load applied at startup, ripple and noise is exceptionally low <4mV P-P measured on the scope.
With a board connected having a 50 mA load I saw no issues with noise.

Measured with the HP400FL analog meter the output noise is -62 dBu (100 kHz filter) and -44 dBu (4 MHz). (-3dB points.)

The CUT35 appears to have two separate converters one for the 5V the second for the bipolar 15V.
It also has two transformers.
The bipolar supply uses a center-tapped transformer with half-wave rectification.
The 5V supply uses a single output winding and a dual diode half-wave rectifier connected in parallel.
There are 4 opto-isolators which cross the galvanic barrier.
The 5V may have one for voltage feedback and the second to detect over-current.
The second pair of optos, on the bipolar supply, along with a second convertor IC suggest voltage feedback for at least one of the channels if not both.

I measured the noise floor of the MS-II connected to the TDK CUT35-5FF and it was as quiet as when powered from the linear bench supply.
That's good enough!
https://ka-electronics.com

SOCIAL MEDIA PLATFORMS should advance FREEDOM OF SPEECH. Yet too many Americans have seen their accounts suspended, banned, or fraudulently reported for unclear “violations” of user policies. No matter your views, if you suspect political bias caused such an action to be taken against you, share your story with President Trump.
White House Tech Censorship Reporting Link: https://whitehouse.typeform.com/to/Jti9QH
The Most Banned Network In The World: https://www.infowars.com/show
BANNED VIDEO - UK Police Escort A Muslim Mob To ATTACK Tommy Robinson:https://www.newswars.com/censored-video ... n-england/

User avatar
mediatechnology
Posts: 3659
Joined: Sat Aug 11, 2007 2:34 pm
Location: Oak Cliff, Texas
Contact:

Re: TDK-Lambda Single, Bipolar and Triple Output Switching Power Supplies for Audio Projects

Post by mediatechnology » Thu May 03, 2018 3:30 pm

I needed to run a Phono Transfer System on overnight burn in and do final QC so I used the TDK CUT35-5FF.

I couldn't distinguish any difference in noise floor between running the low-level preamp on the TDK switcher and a linear bench supply.

The TDK CUT35-5FF triple-output bipolar supply rocks! I think its my "goto" switcher. To bad they don't make it in a desktop.
https://ka-electronics.com

SOCIAL MEDIA PLATFORMS should advance FREEDOM OF SPEECH. Yet too many Americans have seen their accounts suspended, banned, or fraudulently reported for unclear “violations” of user policies. No matter your views, if you suspect political bias caused such an action to be taken against you, share your story with President Trump.
White House Tech Censorship Reporting Link: https://whitehouse.typeform.com/to/Jti9QH
The Most Banned Network In The World: https://www.infowars.com/show
BANNED VIDEO - UK Police Escort A Muslim Mob To ATTACK Tommy Robinson:https://www.newswars.com/censored-video ... n-england/

Post Reply