Post Date : Mar 09, 2023 / Last updated : Apr 14, 2025

These are the NGK INSULATORS, LTD “EnerCera” ET Series reference circuits.

“EnerCera” ET Series features

  • Constant voltage changing is possible, charging IC not required
  • High-speed charging
  • Expected life of 10 years
  • Small, slim, coin-shaped secondary battery that can also be used in 105℃ environments
    • Can be mounted on a circuit board using reflow solder.
  • Bend-resistant ultra-thin battery
    • Supports hot lamination processing, which is the standard manufacturing method for cards.

Lineup

TypeCoinPouch
Part No.ET2016C-RET2016C-HET382704P-Hr
Size(Φ)20mm12.5mm38mm × 27mm
Height
(including terminals)
2.05mm1.3mm0.45mm
Nominal capacity25mAh4mAh20mAh
Nominal voltage2.3V
Charging methodConstant voltage (CV) charging
(Current limiting not required)
Discharge peak current (reference)60mA20mA300mA
Temperature range-40℃~70℃-20℃~105℃-40℃~70℃
Heatproof temperature (mounted)(Reflow solder use not supported)(Supports reflow solder use)(Hot lamination)
As of April 2025

Reference circuit/evaluation circuit board

Evaluation circuit board

Circuit diagram

BOM

BlockProductFeatures
(1)Charging LDOXC6240A263xR-GFor LTO charging, 2.63V, 150mA
XC6242A2637R-GSupports 105℃, for LTO charging, 2.63V, 150mA
(2)Battery voltage monitoringXC6140C20AxR-GLTO battery voltage monitoring IC
Detect voltage 2.0V, release voltage = 2.475V, Iq=104nA
XC6142C20A9R-GSupports 105℃, LTO battery voltage monitoring IC
Detect voltage 2.0V, release voltage = 2.450V, Iq=104nA
SBDXBS024S15R-GFor counter-current prevention, 200mA 40V, low IR
CIN10V/1μFInput capacitor for charging LDO
CL10V/1μFOutput capacitor for charging LDO
R100kΩPull-down resistor

(1) LDO for LTO battery charging: XC6240, XC6242

  • Max. 2.70V charging voltage, including the temperature range, to match the LTO battery specifications.
  • Designed to hold down the current discharged from the battery.
  • Supports LTO batteries that support high-temperature operation (XC6242: 105℃)
  • h = 0.33 low-profile package that can also support thin-package solutions.

(2) Battery voltage monitor: XC6140, XC6142

  • Optimum detect voltage for over-discharge protection of LTO batteries.
  • Release voltage is released when charging starts.
  • Broad hysteresis range that can output a stable signal even when using LTO batteries with a high internal impedance.
  • Ultra-low power-consuming current that keeps down the discharge current from the battery.
  • Supports LTO batteries that support high-temperature operation (XC6142: 105℃).
  • h = 0.33 low-profile package that can also support thin-package solutions.