Claims
- 1. A portable communication package comprising:
a first battery-powered communication device and a second battery-powered communication device, said second communication device having power consumption requirements which are at least an order of magnitude greater than those of the first communication device; at least one battery supplying a flow of electricity for powering both communication devices, said at least one battery having first and second output terminals, said first output terminal having a potential that is positive with respect to the potential of said second output terminal; a power management unit for providing an uninterrupted flow of electricity to said first communication device for a predetermined period although said battery has insufficient capacity for providing an uninterrupted flow of electricity to said second communication device for said predetermined period, said power management unit comprising:
an oscillator having a clock signal; an inverter including a P-channel FET having a gate coupled to said clock signal and a channel coupling said first output terminal to an output node, and an N-channel FET having a gate coupled to said clock signal and a channel coupling said second output terminal to said output node; a current-limiting resistor; an intermediate FET having a gate and a channel connected in series with said current-limiting resistor coupling said first output terminal to said second output terminal; a plurality of series-coupled diodes coupling said output node to the gate of said intermediate FET; and a flyback inductor through for current from a storage device to intermittently flow, such intermittent flow being controlled by said intermediate FET to provide a pulsating flyback voltage after the rectification and filtering thereof gives an output voltage for powering said second communication device.
- 2. The portable communication package of claim 1, wherein said at least one single battery includes a first battery and second battery which together constitute a supply of electricity, said first battery providing power to said first communication device, and said second battery providing power to said second communication device.
- 3. The portable communication package of claim 2, wherein said first battery comprises an electrochemical cell and said second battery comprises a battery of a plurality of electrochemical cells.
- 4. The portable communication package of claim 1, wherein said power management unit includes:
a reference voltage; a measured voltage representative of a charge level of said battery; a switch for cutting the flow of electricity from said storage device to said second battery-powered communication device when the measured voltage drops below a predetermined level that corresponds to a minimum battery charge level required for continued operation of the first battery-powered communication device for a desired period of time.
- 5. The portable communication package of claim 4, wherein a silicon bandgap circuit produces said reference voltage.
- 6. The portable communication package of claim 4, wherein a voltage divider circuit produces said measured voltage.
- 7. The portable communication package of claim 4, which further comprises a comparator including:
an output; a first input coupled to said reference voltage; and a second input coupled to said measured voltage.
- 8. The portable communication package of claim 4, wherein said switch is a transistor controlled by said comparator output.
- 9. The portable communication package of claim 4, wherein said first communication device is a pager, and said second communication device is a wireless telephone.
- 10. The portable communication package of claim 1, which further comprises:
an intermediate node interposed between said current-limiting resistor and said intermediate FET; a final FET having a gate coupled to said intermediate node through at least one buffer, said final FET and said flyback inductor providing a serial current path between said first and second output terminals; and a final node within the serial current path interposed between said flyback inductor and said final FET, said intermittent power output taken from said final node within the serial current path.
- 11. The portable communication package of claim 1, wherein said intermediate FET and said final FET are both N-channel devices.
- 12. The portable communication package of claim 11, further comprising:
an adjustment resistor interposed in the serial current path having a resistance value setting the output voltage.
- 13. The portable communication package of claim 1, further comprising:
a flyback shut-off transistor controlled by said output voltage for disabling said inverter when said output voltage reaches a preset level.
- 14. The portable communication package of claim 13, further comprising: a voltage divider which adjusts said preset level.
- 15. In combination with at least two communication devices packaged in a single portable unit having a single battery providing power for operating said devices, a power management unit comprising:
an oscillator producing a clock signal; an inverter including a P-channel FET having a gate coupled to said clock signal and a channel coupling a first output terminal to an output node, and an N-channel FET having a gate coupled to said clock signal and a channel coupling a second output terminal to said output node; a current-limiting resistor; an intermediate FET having a gate and a channel in series with said current-limiting resistor coupling a first output terminal to a second output terminal; a plurality of series-coupled diodes coupling said output node to the gate of said intermediate FET; a flyback inductor through which current from a storage device intermittently flows being controlled by said intermediate FET for providing intermittent output power subsequent to rectification and filtering powers a second communication device; an intermediate node interposed between a current-limiting resistor and an intermediate FET; a final FET having a gate coupled to said intermediate node through at least one buffer, said final FET and said flyback inductor providing a serial current path between said first and second output terminals; and a final node within the serial current path, said final node interposed between said flyback inductor and said final FET for said intermittent output power being taken from the final node.
- 16. The combination of claim 15, wherein said intermediate FET and said final FET are both N-channel devices.
- 17. The combination of claim 15, wherein said power management unit further comprises:
an adjustment resistor interposed in the serial current path having a resistance value setting an output voltage.
- 18. In combination with a wireless communication device and a pager device packaged in a single portable unit having a single battery providing power for operating both of said devices, a power management unit comprising:
an oscillator producing a clock signal; an inverter having both a P-channel FET having a gate coupled to said clock signal and a channel coupling a first output terminal to an output node and an N-channel FET having a gate coupled to said clock signal and a channel coupling a second output terminal to said output node; a current-limiting resistor; an intermediate FET having a gate and a channel connected in series with said current-limiting resistor coupling a first output terminal to a second output terminal; a plurality of series-coupled diodes coupling said output node to the gate of said intermediate FET; and a flyback inductor through which current from a storage device intermittently flows being controlled by said intermediate FET to provide intermittent output power subsequent to the rectification and filtering thereof powers said second communication device.
- 19. The combination of claim 18, wherein said power management unit further comprises:
an intermediate node interposed between said current-limiting resistor and said intermediate FET; and a final FET having a gate coupled to said intermediate node through at least one buffer, said final FET and said flyback inductor providing a serial current path between said first and second output terminals, said intermittent output power being taken from a final node within the serial current path, said final node interposed between said flyback inductor and said final FET.
- 20. The combination of claim 19, wherein said intermediate FET and said final FET are both N-channel devices.
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of application Ser. No. 09/066,616, filed Apr. 24, 1998, pending.
Continuations (1)
|
Number |
Date |
Country |
Parent |
09066616 |
Apr 1998 |
US |
Child |
09758838 |
Jan 2001 |
US |