MAX610 MAXIM [Maxim Integrated Products], MAX610 Datasheet - Page 7

• Manufacturer Part Number: MAX610
• Description: AC-to-DC Regulator(110/220VAC to 5.0VDC)
• Manufacturer: MAXIM [Maxim Integrated Products]

Figure 12 shows a +5V power supply that works even if
the battery is installed backwards: the full-wave bridge
rectifier of the MAX612 corrects the battery polarity.
The MAX612 is well suited for battery-powered circuits
since its quiescent current is only 70µA. The MAX610
can also be used if the battery voltage is less than 10V.
The +6.7V open circuit or float voltage of Figure 13 is
set by R2 and R3; the maximum charging current of
60mA is set by the value of C1. Since, unlike trans-
former-driven battery chargers, C1 conducts current
throughout most of each line cycle, the ratio of the RMS
charging current to the average charging current is
only about 1.2:1, and capacitor C2 is optional.
I
current) (A)
F
I
I
The half-wave MAX611 can also be used in this circuit,
but the value of C1 must be doubled and the ratio of
RMS current to average current increases to about
1.7:1.
Figure 9b. Power-Up Reset Delay
AVG(MAX)
RMS
RMS
IN
= Input Frequency
= 1.2 I
= I
(SINKING CURRENT)
AVG
= V
AVG
OUV
V
; with C2.
OUT
V+
IN
(OPEN)
; without C2
OFF
ON
x 5.56 F
_______________________________________________________________________________________
+1.5V
0V
Battery-Powered Supply
4.65V
+6V
IN
x C1 (maximum charging
Polarity Insensitive
+12V
MOMENTARILY
SHORTED
OUTPUT
Battery Charger
t
DELAY
t < t
(110/220VAC to 5.0VDC)
t
DELAY
DELAY
500
Figure 10. Driving Triacs with +12V Supply
LOAD
AC
TO
t
DELAY
LOAD
AC
117VAC
POWER
LINE
1/2W
47
R1
AC-to-DC Regulator
2 F
1M
C1
1k
POWER SUPPLY
5.36V
TO ANOTHER
7
1
4
SHORTED
OUTPUT
AC1
N.C.
RD
t
DELAY
V-
INDETERMINATE
WHEN V+ < 1.8V
2
MAX611
OUV OUTPUT
470 F
15V
V
SENSE
V
V+
OUV
OUT
8
LEVEL SHIFTER
OR MM74C907
6
5
3
BUFFER SUCH
+12V OUTPUT
AS MC14504
COLLECTOR
OR OPEN-
+5V
+1.5V
LOGIC
LEVEL
CONTROL
5V
SYSTEM
7