Rainbow Electronics MAX1765 - Manual (Page 18)

MAX1765
the regulator turns on. The switch must be pressed
long enough for the microcontroller (µC) to exit reset
and drive ONA high. A small capacitor is added to help
debounce the switch. The µC issues a logic high to
ONA, which holds the device on, regardless of the
switch state. To turn the regulator off, press the switch
again, allowing the µC to read the switch status and
pull ONA low. When the switch is released, ONB is
pulled high.
800mA, Low-Noise, Step-Up DC-DC Converter
with 500mA Linear Regulator
18 ______________________________________________________________________________________
Table 5. Typical Available Output Current
NUMBER OF CELLS
INPUT VOLTAGE
(V)
OUTPUT VOLTAGE
(V)
OUTPUT CURRENT
(mA)
1 NiCd/NiMH 1.2 3.3 330
2.4 3.3 730
2 NiCd/NiMH
2.4 5.0 460
3 NiCd/NiMH or 1 Li+ 3.6 5.0 720
PA
RF
LX POUT
GND OUTL
CONTROL
INPUTS
µ
C
I/O
MAX1765
INL
µC
V DD
I/O
ONA
ONB POUT
I/O
0.1 µF
ON/OFF
270k
270k
MAX1765
Chip Information
TRANSISTOR COUNT: 1735
Figure 10. Typical Phone Application
Figure 11. Momentary Pushbutton On/Off Switch