Difference between revisions of "Gps1"
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**, need to watch for cell reversal and over discharge. indefinite charge at C/300, but a C/10 charge can be used for limited time. [[http://en.wikipedia.org/wiki/Nickel-metal_hydride_battery#Charging]] | **, need to watch for cell reversal and over discharge. indefinite charge at C/300, but a C/10 charge can be used for limited time. [[http://en.wikipedia.org/wiki/Nickel-metal_hydride_battery#Charging]] | ||
** probably can just use a CV charger and use the CPU to monitor cell voltage. Will use USB to make it easy. | ** probably can just use a CV charger and use the CPU to monitor cell voltage. Will use USB to make it easy. | ||
+ | ** LT3684 36V 2A 2.8 MHz buck : [[http://www.linear.com/pc/productDetail.jsp?navId=H0,C1,C1003,C1042,P37361]] | ||
==LCD display== | ==LCD display== |
Revision as of 21:40, 16 July 2009
Contents
power management
- 3 to 4.2 LiPo (1.3 Ahr) - 26 hrs @ 50mA
- Need upower LV cutoff.
Battery charger
- LIPO : LT3650-8.2 [[1]]
- NiMh
- NImi - charge at upto 1C
- charge voltage of 1.4-1.6V / cell, fully charged cell of 1.35 to 1.4, discharged at 1.0 to 1.1 V / cell
- , need to watch for cell reversal and over discharge. indefinite charge at C/300, but a C/10 charge can be used for limited time. [[2]]
- probably can just use a CV charger and use the CPU to monitor cell voltage. Will use USB to make it easy.
- LT3684 36V 2A 2.8 MHz buck : [[3]]
LCD display
- 5V @ 1.5mA
- TPS61220 boost converter - very efficient at lite load
LCD back light
- 3.8 - 4.2V @ 240mA max,
- LTC3454 - LED driver.
dsPICsupply
- 3.0V @ upto 100mA GPS
- TPS63030 (buck - boost)
GPS
- direct to LiPo,
- or through LDO - TPS780xx Iq=500nA, 150mA output.
- TPS735xx 25mW @ 50mA, 500mA max, IQ 46uA
- TPS734xx 25mV @ 50mA, 250mA IQ 44ua
- TPS799xx 25mV @ 50mA, 200mA, 40uA
- LOCOSYS LS20031/33 - direct Lipo connections! (41/44 mA)