GB2328844A - Portable appliance power supply - Google Patents

Portable appliance power supply Download PDF

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Publication number
GB2328844A
GB2328844A GB9718471A GB9718471A GB2328844A GB 2328844 A GB2328844 A GB 2328844A GB 9718471 A GB9718471 A GB 9718471A GB 9718471 A GB9718471 A GB 9718471A GB 2328844 A GB2328844 A GB 2328844A
Authority
GB
United Kingdom
Prior art keywords
power
bursts
battery
amplifier
power supply
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB9718471A
Other versions
GB2328844B (en
GB9718471D0 (en
Inventor
Mark Corbridge
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Technologies UK Ltd
Original Assignee
NEC Technologies UK Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by NEC Technologies UK Ltd filed Critical NEC Technologies UK Ltd
Priority to GB9718471A priority Critical patent/GB2328844B/en
Publication of GB9718471D0 publication Critical patent/GB9718471D0/en
Publication of GB2328844A publication Critical patent/GB2328844A/en
Application granted granted Critical
Publication of GB2328844B publication Critical patent/GB2328844B/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B15/00—Suppression or limitation of noise or interference
    • H04B15/005—Reducing noise, e.g. humm, from the supply
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/38—Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
    • H04B1/40—Circuits
    • H04B1/54—Circuits using the same frequency for two directions of communication
    • H04B1/56—Circuits using the same frequency for two directions of communication with provision for simultaneous communication in two directions
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J2207/00—Indexing scheme relating to details of circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J2207/20—Charging or discharging characterised by the power electronics converter
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B2215/00—Reducing interference at the transmission system level
    • H04B2215/061—Reduction of burst noise, e.g. in TDMA systems
    • H04B2215/063—Reduction of burst noise, e.g. in TDMA systems by smoothing the transmission power envelope
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B2215/00—Reducing interference at the transmission system level
    • H04B2215/069—Reduction of switch mode power supply ripple

Abstract

When a GSM cellular mobile radio telephone is operating in transmit mode with high transmitter power, too great a voltage and current is required to enable an RF power amplifier 10 to be satisfactorily supplied from a lithium ion battery 14. When the required amplifier power exceeds a threshold, the CPU of the telephone therefore activates a voltage boosting switch mode power supply integrated circuit 12 to charge a capacitor 13 from the battery 14. Transmission occurs in bursts, and the IC 12 is activated between bursts so that sufficient energy is stored in the capacitor 13 between bursts to sustain proper operation of the amplifier 10 during each burst. Disabling of the IC except when the phone is in a high power transmission mode ensures that the power taken from the battery 14 is minimised, and disabling the IC 12 during the actual transmission bursts ensures that interference is avoided.

Description

POWER SUPPLY FOR USE IN A PORTABLE APPLIANCE This invention relates to a power supply for use in a portable appliance.
In a GSM mobile radio station, the battery is required to supply power for intermittent radio transmission. The transmission power level is adjustable by the CPU included in the mobile radio station to ensure that signals transmitted are strong enough to be received properly by a base station, but no stronger, thereby enabling battery power to be conserved.
When the battery used is, for example, a Lithium ion battery, which has a relatively high internal resistance, it is difficult with conventional power supply arrangements to arrange for sufficient power to be available for high transmission levels, without having power wasted when the transmission level needs to be only low.
In accordance with the invention there is provided a portable appliance including a battery, a power amplifier which intermittently draws power from the battery, means for varying the power level of the power amplifier, a storage capacitor connected to supply power to the power amplifier, a switching power supply circuit connecting the battery to the storage capacitor and means for rendering the switching power supply circuit inoperative except when the power level of the power amplifier is above a threshold level.
Preferably, the switching power supply circuit, is rendered inoperative during bursts of operation of the power amplifier.
The accompanying drawing is a circuit diagram of an example of a power supply in accordance with the invention as applied to the supply of power to the RF transmitter amplifier stage of a GSM mobile phone.
The mobile phone includes a RF power amplifier 10 which receives encoded signals from the DSP of the phone and amplifies these to the required transmission power. The transmission power is variable by a power level controller 1 1 which operates in known manner, employing a closed loop power control system which varies the voltage on the drain supply of the power amplifier under the control of the DSP of the phone.
In the GSM system, transmission occurs in bursts with a duty cycle of 1/8. In some phones the higher power levels will require too great a voltage and current to enable the power amplifier to be satisfactorily supplied from the lithium ion battery 14.
A switch mode power supply ic 12 is used in a configuration such that it can charge a 470 ,uF capacitor 13 sufficiently between bursts to allow enough energy to be stored in the capacitor 13 to sustain proper running of the amplifier during each burst.
The ic 12 is a LT1304 ic (manufactured by Linear Technology Corporation) and the nomenclature used for the pins of the ic is that used in the data sheet therefore. The VIN pin of the ic is connected to the positive terminal of the battery 14 and its GDN and LB1 pins are connected to the (grounded) negative terminal of the battery. A 22 pH inductor 15 connects the battery positive terminal to the anode of a diode 16 which has its cathode connected to the input of the power level controller 11. The SW pin of the ic is connected to the anode of the diode 16. The ILIUM pin of the ic is connected to ground by the parallel combination of a resistor 17 and a capacitor 18 which act to limit the current through the inductor to a few hundred milliamps. The SHDN pin of the ic is connected to the CPU of the phone so that the ic can be shutdown when required by the CPU. The FB (feedback) pin of the ic is connected to ground by a resistor 19 and to the cathode of diode 16 by a resistor 20. Also connected to the FB pin is one end of a resistor 22 the other end of which is connected to a control line from the CPU.
In use, the CPU activates the ic between transmission bursts when the required amplifier power level setting exceeds a threshold. The voltage to which the capacitor 13 is charged is limited by feedback to the FB pin of the ic and depends on the voltage applied to resistor 22. When lower amplifier power is required, the CPU holds the SHDN pin at ground, so that the ic 12 does not run. The battery voltage is sufficient in these circumstances for the required lower power levels to be attained.
Disabling the power supply ic 12 except when high power level transmission bursts are required ensures that the power taken from the battery is minimised. Disabling the ic 12 during power transmission bursts also ensures that interference is avoided.
The battery voltage in the example described above is typically 3.3V, and the voltage to which the capacitor 13 is charged, for GSM power level 5, is 6 volts, allowing the voltage to remain high enough during the transmission burst to maintain the required power level throughout the transmission burst.

Claims (5)

1. A portable appliance including a battery, a power amplifier which intermittently draws power from the battery, means for varying the power level of the power amplifier, a storage capacitor connected to supply power to the power amplifier, a switching power supply circuit connecting the battery to the storage capacitor and means for rendering the switching power supply circuit inoperative except when the power level of the power amplifier is above a threshold level.
2. A portable appliance as claimed in Claim 1, in which the power amplifier is operable in use in bursts and the switching power supply circuit is operated only between bursts.
3. A portable appliance as claimed in Claim 1 or Claim 2, in which the voltage to which said storage capacitor is charged in each cycle of operation is variable.
4. A portable appliance as claimed in any preceding claim further comprising a CPU which controls said means for rendering the switching power supply circuit inoperative.
5. A portable appliance substantially as hereinbefore described with reference to the accompanying drawing.
GB9718471A 1997-09-02 1997-09-02 Power supply for use in a portable appliance Expired - Fee Related GB2328844B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB9718471A GB2328844B (en) 1997-09-02 1997-09-02 Power supply for use in a portable appliance

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB9718471A GB2328844B (en) 1997-09-02 1997-09-02 Power supply for use in a portable appliance

Publications (3)

Publication Number Publication Date
GB9718471D0 GB9718471D0 (en) 1997-11-05
GB2328844A true GB2328844A (en) 1999-03-03
GB2328844B GB2328844B (en) 2002-03-27

Family

ID=10818322

Family Applications (1)

Application Number Title Priority Date Filing Date
GB9718471A Expired - Fee Related GB2328844B (en) 1997-09-02 1997-09-02 Power supply for use in a portable appliance

Country Status (1)

Country Link
GB (1) GB2328844B (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2788647A1 (en) * 1999-01-18 2000-07-21 Cit Alcatel POWER SUPPLY FOR RADIOCOMMUNICATION TERMINAL
FR2792781A1 (en) * 1999-04-26 2000-10-27 Cit Alcatel METHOD AND DEVICE FOR POWER SUPPLY IN A MOBILE DEVICE
GB2366134A (en) * 2000-07-18 2002-02-27 Nokia Mobile Phones Ltd Portable battery driven telephone which compares estimated battery operation time with transfer time and allows data transfer if the latter exceeds the former
WO2004040744A1 (en) * 2002-10-30 2004-05-13 Koninklijke Philips Electronics N.V. Audio system with inactive smps during tuner search
WO2005004300A1 (en) * 2003-06-30 2005-01-13 Motorola Inc Apparatus and method for power distribution
WO2006117337A1 (en) * 2005-05-04 2006-11-09 Siemens Aktiengesellschaft Tdma communication device with a pwm component
GB2438257A (en) * 2006-05-20 2007-11-21 Ford Global Tech Llc Receiving apparatus having a low quiescent current
EP2042965A3 (en) * 2007-09-26 2016-07-27 Enphase Energy, Inc. Method and apparatus for power conversion with maximum power point tracking and burst mode capability

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1994011799A1 (en) * 1992-11-10 1994-05-26 Motorola, Inc. Switching regulator and amplifier system
US5423078A (en) * 1993-03-18 1995-06-06 Ericsson Ge Mobile Communications Inc. Dual mode power amplifier for analog and digital cellular telephones
GB2308950A (en) * 1996-01-08 1997-07-09 Matsushita Communication Ind U Power supply for intermittent load
GB2310570A (en) * 1996-02-21 1997-08-27 Motorola Israel Ltd Subscriber unit with power supply operable in linear and switched modes; portable radio data packet modem

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1994011799A1 (en) * 1992-11-10 1994-05-26 Motorola, Inc. Switching regulator and amplifier system
US5423078A (en) * 1993-03-18 1995-06-06 Ericsson Ge Mobile Communications Inc. Dual mode power amplifier for analog and digital cellular telephones
GB2308950A (en) * 1996-01-08 1997-07-09 Matsushita Communication Ind U Power supply for intermittent load
GB2310570A (en) * 1996-02-21 1997-08-27 Motorola Israel Ltd Subscriber unit with power supply operable in linear and switched modes; portable radio data packet modem

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2788647A1 (en) * 1999-01-18 2000-07-21 Cit Alcatel POWER SUPPLY FOR RADIOCOMMUNICATION TERMINAL
EP1024612A1 (en) * 1999-01-18 2000-08-02 Alcatel Powersupply for a radio communications terminal
US6552446B1 (en) 1999-04-26 2003-04-22 Alcatel Method and device for electric supply in a mobile apparatus
WO2000065735A1 (en) * 1999-04-26 2000-11-02 Alcatel Method and device for electric supply in a mobile apparatus
EP1049262A1 (en) * 1999-04-26 2000-11-02 Alcatel Method and device for electrical supply of a mobile apparatus
FR2792781A1 (en) * 1999-04-26 2000-10-27 Cit Alcatel METHOD AND DEVICE FOR POWER SUPPLY IN A MOBILE DEVICE
GB2366134A (en) * 2000-07-18 2002-02-27 Nokia Mobile Phones Ltd Portable battery driven telephone which compares estimated battery operation time with transfer time and allows data transfer if the latter exceeds the former
GB2366134B (en) * 2000-07-18 2004-02-18 Nokia Mobile Phones Ltd Mobile data transmission
WO2004040744A1 (en) * 2002-10-30 2004-05-13 Koninklijke Philips Electronics N.V. Audio system with inactive smps during tuner search
WO2005004300A1 (en) * 2003-06-30 2005-01-13 Motorola Inc Apparatus and method for power distribution
WO2006117337A1 (en) * 2005-05-04 2006-11-09 Siemens Aktiengesellschaft Tdma communication device with a pwm component
GB2438257A (en) * 2006-05-20 2007-11-21 Ford Global Tech Llc Receiving apparatus having a low quiescent current
GB2438257B (en) * 2006-05-20 2011-01-26 Ford Global Tech Llc Receiving apparatus having a low quiescent current
EP2042965A3 (en) * 2007-09-26 2016-07-27 Enphase Energy, Inc. Method and apparatus for power conversion with maximum power point tracking and burst mode capability

Also Published As

Publication number Publication date
GB2328844B (en) 2002-03-27
GB9718471D0 (en) 1997-11-05

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Legal Events

Date Code Title Description
732E Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977)
PCNP Patent ceased through non-payment of renewal fee

Effective date: 20050902