MAX618EEE データシートの表示（PDF） - Maxim Integrated
部品番号
コンポーネント説明
メーカー
MAX618EEE Datasheet PDF : 15 Pages
| |||
MAX618
28V Internal Switch, Step-Up DC-DC Converter
Operating Configurations
The MAX618 can be connected in one of three configura-
tions described in Table 2 and shown in Figures 1, 3, and
4. The VL linear regulator allows operation from a single
supply between +3V and +28V as shown in Figure 1.
The circuit in Figure 3 allows a logic supply to power
the MAX618 while using a separate source for DC-DC
conversion power (inductor voltage). The logic supply
(between 2.7V and 5.5V) connects to VL and IN. VL = IN;
voltages of 3.3V or more improve efficiency by providing
greater gate drive for the internal MOSFET.
The circuit in Figure 4 allows separate supplies to power
IN and the inductor voltage. It differs from the connection
in Figure 3 in that the MAX618 chip supply is not limited
to 5.5V.
Table 2. Input Configurations
CIRCUIT CONNECTION
Figure 1
Input voltage
connects to IN
and inductor.
VIN RANGE
INDUCTOR
VOLTAGE
3V to VOUT
(up to 28V)
VIN
Figure 3
IN and VL
connect together.
Inductor voltage
supplied by a
separate source.
2.7V to 5.5V
0V to VOUT
(up to 28V)
Figure 4
IN and inductor
voltage supplied
by separate
sources.
3V to 28V
0V to VOUT
(up to 28V)
BENEFITS/COMMENTS
• Single supply operation.
• SHDN must be connected to or pulled up to VL. On/off control
requires an open-drain or open-collector connection to SHDN.
• Increased efficiency.
• SHDN can be driven by logic powered from the supply
connected to IN and VL, or can be connected to or pulled up
to VL.
• Input power source (inductor voltage) is separate from the
MAX618’s bias (VIN = VL) and can be less than or greater
than VIN.
• Input power source (inductor voltage) is separate from the
MAX618’s bias (VIN) and can be less than or greater than VIN.
• SHDN must be connected to or pulled up to VL. On/off control
requires an open-drain or open-collector connection to SHDN.
VIND
UP TO 28V
CIND
IN
2.7V TO 5.5V
1µF
4.7µF
CCOMP
L
IN
LX
MAX618
SHDN
VL
PGND
FB
COMP
GND
COUT
CP
OUT
UP TO 28V
R1
R2
Figure 3. Dual-Supply Operation (VIN = 2.7V to 5.5V)
VIND
UP TO 28V
IN
3V TO 28V
1µF
L
CIND
IN
LX
MAX618
SHDN
PGND
VL
4.7µF
FB
CCOMP
COMP
GND
COUT
OUT
UP TO 28V
R1
CP
R2
Figure 4. Dual-Supply Operation (VIN = 3V to 28V)
www.maximintegrated.com
Maxim Integrated │ 9
Share Link: 