MAX683 MAXIM [Maxim Integrated Products], MAX683 Datasheet - Page 8

• Manufacturer Part Number: MAX683
• Description: 3.3V-Input to Regulated 5V-Output Charge Pumps
• Manufacturer: MAXIM [Maxim Integrated Products]

3.3V-Input to Regulated 5V-Output
Charge Pumps
Table 2. Recommended Capacitor Values
for Quiescent Current (Skip Mode)
Table 3. Recommended Capacitor Values
for Smallest Size (Constant-Frequency
Mode, I
Table 4. Recommended Capacitor
Manufacturers
In addition, the following two equations approximate
output ripple for each mode. In skip mode, output rip-
ple is dominated by ESR, and is approximately:
8
MAX683
MAX684
MAX682
MAX682
MAX683
MAX684
PART
0.1µF to
47µF to
47µF to
PART
VALUE
2.2µF
10µF
10µF
_______________________________________________________________________________________
V
RIPPLE(SKIP)
OUTPUT
S S H H D D N N
(mA)
OUTPUT
250
100
DESCRIPTION
595D-series
tantalum
surface mount
TPS-series
surface mount
Ceramic
surface mount
50
(mA)
250
100
50
= 22µA, 1MHz)
(µF)
0.47
C
2.2
1
IN
0.47
0.22
(µF)
C
(2V
1
0.47
0.22
(µF)
IN
C
1
X
IN
MANUFACTURER
TANTALUM
- V
0.47
0.22
(µF)
0.1
C
Sprague
X
OUT
TDK
47
22
10
AVX
C
)ESR
OUT
CERAMIC
C
(µF)
0.47
CERAMIC
2.2
(µF)
OUT
1
COUT
4.7
2.2
10
[phone]
[phone]
[phone]
NUMBER
/ R
PHONE
RIPPLE
TX
V
RIPPLE
(mV)
OUT
80
80
80
V
(mV)
100
100
100
OUT
Figure 6. Paralleling Two MAX682s
where ESR
tance, and R
ance of the IC. R
1.6Ω for the MAX683, and 3Ω for the MAX684. In con-
stant-frequency mode, output ripple is dominated by
C
All capacitors must maintain a low (<100mΩ) equiva-
lent series resistance (ESR). Table 4 lists the manufac-
turers of recommended capacitors. Surface-mount
tantalum capacitors will work well for most applications.
Ceramic capacitors will provide the lowest ripple due to
their typically lower ESR.
If the source impedance or inductance of the input sup-
ply is large, additional input bypassing (2.2µF to 22µF)
may be needed. This additional capacitance need not
be a low-ESR type.
Figure 5. Standard Operating Circuit
3.3V
1 F
OUT
IN
OFF
V
0.47 F
100k
and is approximately:
RIPPLE(const-freq)
ON
IN
V
ON
COUT
C
CXP
CXN
SKIP
SHDN
TX
IN
R
EXT
GND
IN
MAX682
is the open-loop output transfer resist-
is the ESR of the output filter capaci-
TX
2
3
1
PGND
OUT
SHDN
IN
SKIP
is typically 0.8Ω for the MAX682,
4
GND
I
OUT
0.47 F
1 F
MAX682
MAX683
MAX684
100k
/ (2 x f
PGND
5
SKIP
SHDN
CXP
CXN
GND
IN
CXN
OSC
CXP
OUT
MAX682
7
6
8
PGND
x C
OUT
OUT
5V/500mA
C
C
X
OUT
OUT
)
4.7 F