Thin film microbattery charge and output control
A control system for charge and output control of a rechargeable thin film microbattery cell comprises a charge control logic component configured to control the level of charge of a thin film microbattery cell, a battery cut-off logic component to cease current draw on the thin battery thin film microbattery cell under predetermined conditions, a mode control logic component operably coupled to the charge control logic component and the battery cut-off logic component to enable operation of the charge control logic component and the battery cut-off logic component under predetermined conditions, and a Switch Capacitor DC-DC Downconverter Component for delivery of voltage external to the system configured to reduce battery output voltage potential by a factor of at least 2:1. Systems operably connected to a rechargeable thin film microbattery cell and powered devices comprising the system and the microbattery cell are also described.
1. A control system for charge and output control of a rechargeable thin film microbattery cell comprising
a charge control logic component configured to control the level of charge of a thin film microbattery cell, wherein the charge control logic component comprises a charge pump unit, a temperature controller reference that measures the ambient temperature of the system, and a temperature controlled shunt regulator, wherein the charge control logic is programmed to reduce the voltage of the thin film microbattery when the ambient temperature of the system exceeds a predetermined value by operation of the temperature controlled shunt regulator,
a battery cut-off logic component to cease current draw on the thin battery thin film microbattery cell under predetermined conditions,
a mode control logic component operably coupled to the charge control logic component and the battery cut-off logic component to enable operation of the charge control logic component and the battery cut-off logic component under predetermined conditions, and
a Switch Capacitor DC-DC Downconverter Component for delivery of voltage external to the system configured to reduce battery output voltage potential by a factor of at least 2:1.
2. The system of claim 1 , wherein the charge pump unit of the charge control logic component is one of a switch capacitor DC-DC boost converter or an inductive boost converter.
3. The system of claim 1 , wherein the predetermined value of the ambient temperature is about 23 degrees C. and the voltage of the thin film microbattery is reduced according to an algorithm of about 2 to 2.5 mV per degrees C. above 23 degrees.
4. The system of claim 1 , wherein the battery cut-off logic component operates to disconnect the battery from a load when the battery voltage is reduced to a value at or below a predetermined minimum value.
5. The system of claim 4 , wherein the predetermined minimum value is a value selected from 2.8 to 3.2 volts.
6. The system of claim 1 , wherein the battery cut-off logic component comprises a switch capacitor DC-DC downconverter array to reduce the voltage potential being used by internal circuits of the battery cut-off logic component to a level of from about 10 to about 700 millivolts.
7. The system of claim 1 , wherein the Switch Capacitor DC-DC Downconverter Component for delivery of voltage external to the system reduces the voltage potential by an integer ratio of from 2:1 to 5:1.
8. The system of claim 1 , wherein the Switch Capacitor DC-DC Downconverter Component for delivery of voltage external to the system reduces the voltage potential to from about 0.3 V to about 3.3 V.
9. The system of claim 1 , wherein the Switch Capacitor DC-DC Downconverter Component for delivery of voltage external to the system reduces the voltage potential to from 100 to 500 millivolts.
10. The system of claim 1 , wherein the Switch Capacitor DC-DC Downconverter Component comprises a second switch capacitor DC-DC downconverter array to reduce the voltage potential being used by internal circuits of the battery cut-off logic component to a level of from about 10 to about 700 millivolts.
11. The system of claim 1 , wherein the battery cut-off logic component comprises a circuit configuration to limit leakage currents to a value not exceeding about 30 picoamps.
12. The system of claim 1 , wherein the system does not comprise a linear regulator.
13. The system of claim 1 , wherein the components of the system are located on a single integrated circuit.
14. The system of claim 13 , wherein the system is operably connected to a rechargeable thin film microbattery cell having an effective capacity of no greater than about 500 μAH.
15. The system of claim 14 , wherein the system and the rechargeable thin film microbattery cell are configured as a two terminal connection component to be connected to a powered electronic device.
16. A powered electronic device comprising the system of claim 15 .
17. The system of claim 14 , wherein the system and the rechargeable thin film microbattery cell are configured as a three terminal connection component to be connected to a powered electronic device.
18. A powered electronic device comprising the system of claim 17 .