ADP1621ARMZ-R7(RevB) View Datasheet(PDF) - Analog Devices
Part Name
Description
Manufacturer
ADP1621ARMZ-R7 Datasheet PDF : 32 Pages
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Data Sheet
Low Input and High Output Boost Converter
Figure 36 shows a typical application boost converter circuit
that operates at a switching frequency of 200 kHz with VIN = 5 V
and VOUT = 30 V with a 1 A load. The duty cycle for this circuit
is about 83%. A higher switching frequency can be selected, but
the switching power loss in the MOSFET increases and a bigger
MOSFET is needed. For switch-node voltages greater than 30 V,
a sense resistor, RCS, is needed because the absolute maximum
voltage at CS is 33 V.
High Input Voltage Boost Converter Circuit
Input voltages higher than 5.5 V are possible with the addition
of a resistor and an NPN transistor, as shown in Figure 37, or just
ADP1621
with a single resistor, as shown in Figure 38. When there is a
wide input voltage range, it is sometimes desirable to use the
pass NPN transistor, as shown in Figure 37. If the input voltage
range is narrow, a single resistor connecting to the IN and PIN
pins is sufficient, as shown in Figure 38. In Figure 37, Resistor R3
limits the current going into IN, and there is power loss in this
resistor. The voltages at IN and PIN are both clamped to about
5.5 V, which can rise to as high as 5.9 V when the shunt current
is 30 mA. Refer to Figure 9 for the I-V characteristics of the
shunt regulators. Ensure that Resistor R3 is physically large
enough to handle the power dissipation. For switch-node
voltages higher than 30 V, a current-sense resistor is needed and
the CS pin senses the voltage across the sense resistor.
VIN = 5V
C3
1µF
10V
C2
120pF
L1
7.8µH
C4
0.1µF
10V
RCOMP
1.6MΩ
CCOMP
20pF
IN PIN
FB
ADP1621
SDSN
GATE
COMP
CS
FREQ PGND
GND
RFREQ
100kΩ
1%
D1
R1
115kΩ
1%
R2
4.87kΩ
1%
M1
RS RCS
909Ω 3mΩ
COUT1
1µF
100V
VOUT = 30V
1A
COUT2
4.7µF
50V
COUT3
330µF
50V
×2
C1
47µF
6.3V
×2
AGND
fOSC = 200kHz
C1 = MURATA GRM31CR60J476M
COUT1 = MURATA GRM31CR72A10
COUT2 = MURATA GRM55ER71H475K
COUT3 = RUBYCON 50ZL330M10x23
M1 = VISHAY SUD50N06-07L
D1 = IRF 15TQ060
L1 = COILCRAFT DO501DH-782ML
Figure 36. Low Input, High Output Boost Converter
VIN = 8V TO 15V
C2
120pF
C4
0.1µF
10V
RCOMP
2MΩ
CCOMP
220pF
R3
700Ω
Q1
IN PIN
FB
ADP1621
SDSN
GATE
COMP
CS
FREQ PGND
GND
RFREQ
34.8kΩ
L1
8.2µH
C3
1µF
10V
D1
R1
115kΩ
1%
R2
4.87kΩ
1%
M1
RS RCS
402Ω 3mΩ
COUT1
1µF
100V
VOUT = 30V
1A
COUT2
4.7µF
50V
COUT3
330µF
50V
×2
C1
22µF
16V
×2
AGND
fOSC = 560kHz
C1 = MURATA GRM32ER61C226K
COUT1 = MURATA GRM31CR72A105K
COUT2 = MURATA GRM55ER71H475K
COUT3 = RUBYCON 50ZL220M10x23
M1 = IRF7470
Q1 = SIGNAL NPN TRANSISTOR
D1 = MBRB7H50
L1 = COILCRAFT MSS1260-822ML
Figure 37. High Input Voltage and High Output Voltage Converter
Rev. B | Page 25 of 32
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