Gx64 APPLICATION NOTE Power Management Reference: WI_DEV_Gx64_APN_007 Version: 001 Date: 2007/01/31
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Table of Contents 1 Introduction ............................................................................................ 5 1.1 ABBREVIATIONS ............................................................................................................ 5 1.2 NOTATION.................................................................................................................... 6 1.3 ACKNOWLEDGEMENTS ..................................................................................................
3.7 VRTC AND ALARM ...................................................................................................... 22 3.7.1 4 USING ALARM AS PERIODIC POWER ON ............................................................. 22 Reference Designs ................................................................................ 24 4.1 DISCLAIMER ................................................................................................................ 24 4.2 DC/DC POWER SUPPLY .....................
1 Introduction This document describes how to apply power, control power states (On/Off), and give other hints on how to optimise the Wireless CPU implementation. 1.1 Abbreviations Abbreviation CSD CPS DRX Description Circuit Switched Data Charging Power Supply. Indicates the voltage and current limited supply connected to CHG_IN when battery charging is used. Discontinuous Receive. This indicates how often the Wireless CPU has to wake up and look for a page.
1.2 Notation The following symbols and admonition notation are used to draw the reader’s attention to notable or crucially-important information.
2 Block Diagrams 2.1 System Power Management Block Diagram The GR/GS64 Wireless CPUs have a number of signals in the system connector that affect the power state. The signals in Figure 1 show the signals for all types and variants of the GR/GS64 family of Wireless CPUs. Table 1 below lists what features are available for the different types and variants. Figure 1: System Block Diagram VREF is implemented differently in the two different GR64 variants.
Table 1: Type / Variant Configuration GR64002 GS64 Type VCC PSI √ 1,3,5,7,9 √ 1,3,5,7,9 √ 2,4,6,8,10,12 CHG_IN PSI/PSC √ 11 √ 11 √ 13 VUSB PSI √ 49 √ 34 VREF as input VREF as output 2.
Figure 2: GS64 Power Management Block Diagram 2.2.2 GR64001 This variant of GR64 only implements two PSC-options, ON/OFF and CHG_IN. Figure 3: GR64001 Power Management Block Diagram The “PM ON/OFF Sequence Logic” block diagram can be found in Figure 5. Gx64 APPLICATION NOTE Power Management Page: 9/30 This document is the sole and exclusive property of WAVECOM. Not to be distributed or divulged without prior written agreement. Ce document est la propriété exclusive de WAVECOM.
2.2.3 GR64002 This variant of GR64 implements all four PSC-options, ON/OFF, PON_H, ALARM and CHG_IN. Figure 4: GR64002 Power Management Block Diagram The “PM ON/OFF Sequence Logic” block diagram can be found in Figure 5. Gx64 APPLICATION NOTE Power Management Page: 10/30 This document is the sole and exclusive property of WAVECOM. Not to be distributed or divulged without prior written agreement. Ce document est la propriété exclusive de WAVECOM.
3 Implementation Recommendations This section describes how to implement features related to the Power Management of the Wireless CPUs. 3.1 Applying power on VCC Main power is applied to VCC using GND as reference. The source can be any of the following listed types: • Li-Ion battery (3.7V nominal) • AC/DC power supply (3.6V nominal) • DC/DC power supply (3.6V nominal) Reference designs for AC/DC and DC/DC supplies can be found in Appendix A and B at the end of this document.
3.2 Power state control of the Wireless CPU There are a maximum of six signals that affects the HW power state of the GR/GS64 family of Wireless CPUs; four HW and two SW: • ON/OFF (HW, all Wireless CPUs) • CHG_IN (HW, all Wireless CPUs) • PON_H (HW, GS64 only) • ALARM (HW, GS64 and GR64002 as external, all as internal) • AT+CFUN (SW, all Wireless CPUs) • AT*E2RESET (SW, all Wireless CPUs) Under normal operating conditions, the die temperature should not exceed 125°C.
The two SW power state control signals are not included in Figure 5. This figure only shows the HW-signals. Figure 6: Power Management State Diagram Figure 6 shows the impact five of the six control signals, listed above, have on the Power Management status of the Wireless CPU. The AT*E2RESET is described individually in 3.2.6 below. If a PSC-signal is held active (PON_H high, ON/OFF low, etc.
The signal should be held low for at least tLow time for the Wireless CPU to be able to detect and respond with a power hold signal (PWR_KEEP). The signal can be held low for an unspecified amount of time but it is not recommended since it prevents the Wireless CPU from respond to any other power state signal request. 3.2.2 Internal CHGDET A charge request is initiated on INT_CHGDET when the voltage on CHG_IN is <6.3V, >3.7V, and is 150mV higher than the voltage level of VCC.
3.2.4 ALARM The ALARM-signal can be both an internal and external signal for all Wireless CPUs except GR64001 where it is only an internal signal. Internal means that the RTC is capable of waking up the main processor as long as VCC is available. External means that the signal is provided in the system connector. The external availability enables the application to use an alarm to fully power on not only the Wireless CPU but also itself, see 3.7.1 below.
3.2.5 AT+CFUN This AT-command is used to change the power state of the Wireless CPU. See the AT-command manual for more details. 3.2.6 AT*E2RESET This AT-command will de-register from network and do the normal shut-down sequence, but instead of powering down jump to the reset vector. See the AT-command manual for more details. 3.3 How to lower power consumption The Wireless CPUs are capable of being set to low current consumption mode where the average current consumption can be as low as 1.4mA.
The numbers given above are approximations. The real current levels might differ, but should most often be less than what is listed. 3.4 Charging A CPS should be connected to CHG_IN only if a single Li-Ion battery is used as main power supply. In any other configuration CHG_IN must be left open (not connected). For more information about charging see the “GR/GS64 Series Application Note - Charging Interface”-document. 3.
Figure 7: Interface circuit implementation for GS64 The level translator type used in Figure 7 can be either ST2378E from ST Microelectronics, MAX3001E from Maxim, or any other applicable type. Figure 7 shows a GS64 implementation, but the same figure can be used for a GR64001 solution if the 1.8V regulator is replaced with a 2.8V regulator. VREF can furthermore be used by the application as an indicator whether the Wireless CPU is powered on or not. An active high >1.
Figure 8: Typical VREF level translation implementation in a GR64002 One drawback of this solution is that VREF cannot be used by the application to determine whether the Wireless CPU is powered on or not. See 3.6.2 below for more information. 3.6 Monitor “Power On” State The power state of the Wireless CPU can be verified in two ways; either HW or SW. The HW-determination depends on what product and variant is used, but the SWdetermination is the same for all products (AT+CFUN).
3.6.2 GR64002 HW-detection In GR64002, where VREF is an input to the Wireless CPU the HW-detection of the power state must use SIMDET instead of VREF. The SIMDET-signal is pulled up inside the Wireless CPU to its internal supply voltage (1.8V). It does not go through the built-in level translators as the other logic signals. This can be used to determine the state of the Wireless CPU.
Table 4: Power state transition levels Wireless CPU Power status SIMDET level Power ON >1.5V Power OFF <0.4V It is possible to connect the SIMDET-signal directly to the Application processor, but the integrator must ensure that no voltage is applied onto SIMDET (through pull-up resistors etc.). The Wireless CPU might CAUTION malfunction If the application applies a voltage level onto SIMDET after the Wireless CPU has been powered down.
3.7 VRTC and ALARM These are the two system connector signals that relate to the RTC. VRTC is powered from VCC. If the application wants the RTC to operate even if VCC is removed it has to add a 1.5V “button cell” or capacitor on VRTC as a backup power source. A recommended battery to use is 0.2mAh Pb-free TS414H TIP 3.7.1 from Seiko. Using ALARM as periodic power on It is possible to use the ALARM feature to fully power up the application.
The power supply should be an efficient converter that takes the VIN supply from whatever voltage level the source is providing and converts it to the recommended VCC voltage level. To minimise power consumption this regulator is only enabled when the Wireless CPU is supposed to be active. After the application is installed the “StartUp” button is pressed to initialise the product. This will only have to be done once. perform its own power control.
4 Reference Designs 4.1 Disclaimer Wavecom Inc is not responsible for the charger power supplies reference design. The integrator should refer technical questions regarding the charger power supplies listed below directly to National Semiconductors. 4.2 DC/DC Power Supply The implementation shown in Appendix A is the reference design of a 3.6V DC/DC buck regulator from National Semiconductors. 6VDC to 20VDC. Semiconductors. 4.2.
4.3 AC/DC Power Supply The implementation shown in Appendix B is the reference design of a 3.6V AC/DC flyback regulator from National Semiconductors. The input voltage can be between 85VAC to 265VAC. Semiconductors. 4.3.1 For more information on the design please contact National Specifications Parameter Condition Limit Unit VINmin 85 VAC VINmax 265 VAC 3.65 VDC 140 KHz VOUT 500mA (2.5A peak) Switching Frequency 4.3.
The circuit attains a periodic steady-state in which the volt-seconds across the transformer due to the input voltage are exactly balanced by the volt-seconds due to the output voltage.
4.3.3 Bill Of Material Gx64 APPLICATION NOTE Power Management Page: 27/30 This document is the sole and exclusive property of WAVECOM. Not to be distributed or divulged without prior written agreement. Ce document est la propriété exclusive de WAVECOM.
APPENDIX A Gx64 APPLICATION NOTE Power Management Page: 28/30 This document is the sole and exclusive property of WAVECOM. Not to be distributed or divulged without prior written agreement. Ce document est la propriété exclusive de WAVECOM.
APPENDIX B Gx64 APPLICATION NOTE Power Management Page: 29/30 This document is the sole and exclusive property of WAVECOM. Not to be distributed or divulged without prior written agreement. Ce document est la propriété exclusive de WAVECOM.
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