MAX8614B Maxim Integrated Products, MAX8614B Datasheet - Page 12

• Manufacturer Part Number: MAX8614B
• Description: (MAX8614A / MAX8614B) Dual-Output (+ and -) DC-DC
• Manufacturer: Maxim Integrated Products

For stability, the inverter output filter capacitor, C2,
should satisfy the following:
where R
(MAX8614A). D- is 1 minus the inverter switch duty cycle
and is:
Dual-Output (+ and -) DC-DC
Converters for CCD
Table 1. Inductor Selection Guide
Table 2. Component Suppliers
12
INDUCTORS
Murata
Sumida
TOKO
DIODES
Central
Semiconductor
(CMHSH5-2L)
Motorola
(MBR0540L)
CAPACITORS
Taiyo Yuden
TDK
15V, 50mA
-7.5V, 100mA
15V, 20mA
-7.5V, 40mA
AND LOAD CURRENT
OUTPUT VOLTAGES
______________________________________________________________________________________
SUPPLIER
CS
(R
= 0.0175 (MAX8614B), and 0.040
C2 > (6L V
CS
D- (V
770-436-1300 www.murata.com
847-297-0070 www.tokoam.com
631-435-1110 www.centralsemi.com
602-303-5454 www.motorola.com
408-573-4150 www.t-yuden.com
888-835-6646 www.TDK.com
847-545-600
PHONE
REF
REF
TOKO
DB3018C, 1069AS-2R0
TOKO
DB3018C, 1069AS-4R3
TOKO
S1024AS-4R3M
Sumida
CDRH2D14-4R7
TOKO
S1024AS-100M
Sumida
CDRH2D11-100
Sumida
CDRH2D14-100
Murata
LQH32CN100K33
- V
I
INVMAX
INV
) V
www.sumida.com
INDUCTOR
INV
) /
)
WEBSITE
L (µH)
2.0
4.3
4.3
4.7
10
10
10
10
Table 2 lists representative low-ESR capacitor suppliers.
Although the output current of many MAX8614A/
MAX8614B applications may be relatively small, the
input must be designed to withstand current transients
equal to the inductor current limit. The input bypass
capacitor reduces the peak currents drawn from the
voltage source, and reduces noise caused by the
MAX8614A/MAX8614B switching action. The input
source impedance determines the size of the capacitor
required at the input. As with the output filter capacitor,
a low-ESR capacitor is recommended. A 4.7µF, low-
ESR capacitor is adequate for most applications,
although smaller bypass capacitors may also be
acceptable with low-impedance sources or if the source
supply is already well filtered. Bypass AV
from V
close as possible to the AV
Proper PC board layout is essential due to high-current
levels and fast-switching waveforms that radiate noise.
Breadboards or protoboards should never be used
when prototyping switching regulators.
CC
DCR (mΩ)
with a 0.1µF ceramic capacitor placed as
126
170
100
400
295
300
72
47
PC Board Layout and Routing
D- = V
CC
I
CC
SAT
0.97
0.35
0.46
0.45
1.4
1.2
0.8
/ V
1
and GND pins.
Input Bypass Capacitor
(A)
INV
3.2 x 3.2 x 1.55
3.2 x 3.2 x 1.55
3.2 x 3.2 x 1.2
3.2 x 2.5 x 2
CC
SIZE (mm)
3 x 3 x 1.8
3 x 3 x 1.8
4 x 4 x 1.7
4 x 4 x 1.7
separately