Applied Data Systems Bitsy Plus, Руководство пользователя

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System Specifications
ADS document # 110114-1001A Page 47
6.2.4 Power Supply
Absolute Maximum Ratings
Supply Voltage (DCIN_POS)..................................... 18 V
Symbol Parameter Min Typ. Max Units
System Power
VBATT_POS
Bitsy Plus supply voltage (note 15) 5 12 15 V
Vdin
Diode drop from DCIN_POS to
VBATT_POS at 130 mA
0.35 0.4 V
VDDI Processor core voltage (6.2.10) 1.65 1.75 1.85 V
Run 3.1 3.3 3.5 V
VDDX 3.3 V onboard supply
Sleep 3.15 V
VCC 5.0 V onboard supply 4.75 5.0 5.25 V
Run
I (Vcc)
5 V available for display,
PCMCIA, USB, J9.15,
J10.48, etc. (Note 15)
Sleep
500 mA
Run 700 mA
I (Vddx)
3.3 V available for
display, PCMCIA, J9.23,
J10.47, etc. (note 17)
Sleep 100 mA
Supercapacitor Option (section 5.3.3)
C
Capacitance 1.65 F
Vcap Charge voltage Vcc V
Rcap Series charge resistance 44
Ω
tc Charging time from full discharge 5 min
RTC Backup Power (4.2)
V BATPOS
real-time clock battery backup 2.2 3.0 3.6 V
I BATPOS RTC current (note 18) 300 500 nA
Battery Trickle Charger (section 5.3.7)
Rch
Charger series resistance 37.5
Ω
Pch Charge resistor power rating 0.25 W
Notes:
15. The system can operate down to the minimum voltage shown, but the DC_GOOD signal
may cause the system to go to sleep when running at that voltage. See Power Failure
Interrupt in section 5.3.3 for details. The power failure feature can be overridden, but
DC_GOOD must be valid for the system to wake up from Sleep mode.
16. LTC 1771 "Burst" mode, used when the Bitsy Plus is in Sleep mode, is more efficient at low
currents. However, it is electrically noisier and can cause significantly greater EMI/RFI at
higher current draws.
17. During Sleep mode, Vddx is powered by a linear regulator, which draws from the 5V
supply.
18. Vddx=0V, Vbatpos=3.2 V (source: DS1307 data sheet)