Panasonic has used conductive polymer technology to produce surface-mount aluminium electrolytic capacitors with 3mΩ max equivalent series resistance (ESR, 100kHz +20°C) in a 7.3 x 4.3 x 2.8mm package.

The parts are intended as input or output capacitors on dc-dc converters. Maximum ripple current is 10.2A (100kHz +45°C – less at high temperature).

Called the EEF-GY series, and under the company’s ‘SP-Cap’ brand, there are only two devices:

EEFGY0D821R – 2.0V 820μF

EEFGY0E681R – 2.5V 680μF

Panasonic is clearly excited about these parts:

“The SP-Cap with 3mΩ has the lowest ESR for this technology in the market,” it said when announcing the GY series. “This must be considered as unrivalled at present – and makes the polymer technology a relevant option for microprocessor-based assemblies.”

“Although all that might sound like a footnote of electronical engineering, it isn’t,” said European product manager Shahrokh Kananizadeh. “It is exactly that very composition of ESR, capacitance and ripple current tolerance that make a capacitor an outstanding capacitor. One that turns out in the end of the day to be a crucial component for the long term reliability or – on the contrary – its faultiness.“

Capacitance tolerance is ±20 % (120Hz +20°C) and operation is across -55 to +105°C.

At the parts are primarily for power use, dissipation factor (tan δ) is given as ≤0.06 (120Hz 20°C), and they are surge rated to 1.25x rated voltage (15 to 35°C). Life is 2,000h (+105°C at rated voltage).

Leakage current is worth a mention (rated in μA as ≤0.1CV (2 minutes)) as the data sheet warns against use in:

• high-impedance voltage retention
• coupling
• time-constants
• circuits which are greatly affected by leakage current

Also warned against is using two or more SP-Cap in series.

Those warning are in the data sheet, which is one page of data followed by five pages of caveats – no graph of ESR against frequency, or example. There is a table for allowable ripple current at temperature – which looks like it needs to be well below 3A at 105°C.

Panasonic is pitching the series against multi-layer ceramic capacitors and pure tantalum capacitors in power conversion.