Datasheet
MAX1822
Output Ripple
V
OUT
ripple is typically 50mVp-p with V
CC
= +5V, C1
and C2 = 0.047µF, and C3 = 1µF (Typical Operating
Characteristics). Ripple can be reduced by increasing
the ratio between the output storage capacitors C3 and
C1 and C2. This is usually accomplished by increasing
C3 and keeping C1 and C2 in the 0.01µF to 0.047µF
range. For example, if C1 and C2 are 0.047µF (V
CC
must not exceed 13V) and C3 is 10µF, output ripple
typically falls to 15mV (Typical Operating Character-
istics).
Capacitor Selection
Capacitor type is unimportant when selecting capaci-
tors for the MAX1822. However, when V
CC
exceeds
13V, C1 and C2 must be no greater than 0.01µF. Using
larger value capacitors with input voltages above 13V
causes excessive amounts of energy to pass through
High-Side Power Supply
6 _______________________________________________________________________________________
Figure 2. MAX1822 Quiescent Supply-Current Test Circuit
MAX1822
C4
1000
µ
F
LOW ESR
GND
C3
1.0
µ
F
1
8
5
V
OUT
V
CC
7
C2
0.047
µ
F
4
C1+
V
SUPPLY
C1-
C2+
C2-
6
2
C2
0.047
µ
F
V
A
Figure 3. Single MAX1822 Driving Six High-Side Switches
MAX1822
SW1
SW2
SW3
SW4
SW5
SW6
GND
ALL PULLUP RESISTORS = 1M
74C906
14
1
3
5
9
11
13
2
4
6
8
10
12
7
ALL TRANSISTORS = 1RF541 (NOTE 2)
C4
1µF
C3
10µF
1
8
5
V
OUT
V
CC
7
C2
0.047µF
4
C1+
+5V
C1-
C2+
C2-
6
2
C2
0.047µF
ALL CAPACITORS = 1µF
(NOTE 1)
NOTE 1: 1µF CAPACITORS SUPPRESS SWITCHING TRANSIENTS, SIZE DEPENDS ON LOAD CURRENTS.
NOTE 2: POWER TRANSISTOR TYPE DEPENDS ON LOAD-CURRENT REQUIREMENTS.
TO 1A LOAD
TO 1A LOAD
TO 1A LOAD
TO 1A LOAD
TO 1A LOAD
TO 1A LOAD
6-CHANNEL LOAD SWITCH