Boost Converter Circuit (Step-up)

1. Boost Converter Circuit (Step-up)
Verification and Optimization using PSpice
VIN=5V, VOUT=9V, IOUT=50mA, and
Vripple(P-P)=30mV
L1
150u
1 2
CLP
100p
Q1
Q2SC3526
Rf
1000k
Rsr
180k
Cs
4.7uF
IC = 0
0
0
U1
NJM2377
FOSC = 150K
-IN
FB
GND
OUT
V+
CS
CT
REF
RL
180
OUT
Rt
24k
Ct
470p
IC = 0
0
CIN
220uF
V+
0
Rsf
160k
R1
9.1k
R2
150k
Rs
{ESR}
0
D1
DRB055L-40
PARAMETERS:
ESR = 103m
V2
5Vdc
COUT
220u
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http://www.bee-tech.com/

2. All Rights Reserved Copyright (C) Bee Technologies Inc.
Content
1.Circuit Design Verification:
Design Condition: VIN=5V, VOUT=9V, IOUT=50mA, and Vripple(P-P)=30mV
2.Output Stage Optimization: COUT 220uF
2.1 ESR Characteristics Comparison
2.2 Ripple Voltage Comparison
3 Output Stage Optimization: D1
3.1 Characteristics Comparison
3.2 Diode Performance Comparison
4.Schottky Diode Reverse Characteristics
RB055L-40 Standard vs. Professional Model
4.1 Comparison Result
Voltage, Current, and Power of D1 in Boost Converter Circuit
5 Power Switch: Q1
5.1 Power Switch: Q1
PC, IB, VC, and IC Simulation Result
5.2 Power Switch: Q1
Power Stage Device Stress Analysis

3. Time
118.0ms 118.4ms 118.8ms 119.2ms 119.6ms 120.0ms
-I(RL)
0A
50mA
100mA
V(OUT)
9.045V
9.065V
9.075V
9.085V
9.095V
SEL>>
V(V+) V(OUT)
0V
2.5V
5.0V
7.5V
10.0V
1.Circuit Design Verification
Design Condition: VIN=5V, VOUT=9V, IOUT=50mA, and Vripple(P-P)=30mV
VIN=5V
VOUT=9V
Vripple(P-P)=30mV
IOUT=50mA

4. 2.Output Stage Optimization: COUT 220uF
RJJ-35V221MG5-T20 from ELNA vs.
LXZ25VB220MH12 from Nippon Chemi-Con Corporation
L1
150u
1 2
CLP
100p
Q1
Q2SC3526
Rf
1000k
Rsr
180k
Cs
4.7uF
IC = 0
0
0
U1
NJM2377
FOSC = 150K
-IN
FB
GND
OUT
V+
CS
CT
REF RL
180
OUT
Rt
24k
Ct
470p
IC = 0
0
CIN
220uF
V+
0
Rsf
160k
R1
9.1k
R2
150k
Rs
{ESR}
0
D1
DRB055L-40
PARAMETERS:
ESR = 103m
V2
5Vdc
COUT
220u
ESR

5. 2.1 ESR Characteristics Comparison
RJJ-35V221MG5-T20 from ELNA vs.
LXZ25VB220MH12 from Nippon Chemi-Con Corporation
Part number
ESR()
(Condition: frequency=150kHz)
RJJ-35V221MG5-T20 195m
LXZ25VB220MH12 809m
ELNA
RJJ-35V221MG5-T20
Nippon Chemi-Con Corporation
LXZ25VB220MH12

6. Time
100ms 101ms 102ms 103ms 104ms 105ms
V(OUT)
8.90V
8.95V
9.00V
9.05V
9.10V
9.15V
9.20V
2.2 Ripple Voltage Comparison
RJJ-35V221MG5-T20 from ELNA vs.
LXZ25VB220MH12 from Nippon Chemi-Con Corporation
VIN=5V
Vout ripple for ESR 809m
 150mV
Vout ripple for ESR 195m
 50mV
Total job time (using Solver 1)
= 1437.91 sec. (24min.)

7. 3.Output Stage Optimization: D1
ROHM’s Schottky Diode: RB051L-40 vs. RB055L-40
L1
150u
1 2
CLP
100p
Q1
Q2SC3526
Rf
1000k
Rsr
180k
Cs
4.7uF
IC = 0
0
0
U1
NJM2377
FOSC = 150K
-IN
FB
GND
OUT
V+
CS
CT
REF RL
180
OUT
Rt
24k
Ct
470p
IC = 0
0
CIN
220uF
V+
0
Rsf
160k
R1
9.1k
R2
150k
Rs
{ESR}
0
D1
DRB055L-40
PARAMETERS:
ESR = 103m
V2
5Vdc
COUT
220u
Replace Model

8. 3.1 Characteristics Comparison
ROHM’s Schottky Diode: RB051L-40 vs. RB055L-40
Part number
VF (V)
(Condition: IF=100mA)
Ct (pF)
(Condition: VR=9V)
VR (Max.)
RB051L-40 0.232 213.800 40V
RB055L-40 0.320 69.910 40V
VF-IF characteristics Ct-VR characteristics

9. 3.2 Diode Performance Comparison
ROHM’s Schottky Diode: RB051L-40 vs. RB055L-40
76% PD(rms) Decrease
I(AK)
V(KA)
PD(rms)
The waveforms of DRB051L-40 The waveforms of DRB055L-40

10. 4.Schottky Diode Reverse Characteristics
RB055L-40 Standard vs. Professional Model
0.1
1
10
100
0 10 20 30 40
REVERSE
CURRENT:IR(uA)
REVERSE VOLTAGE：VR(V)
VR-IR CHARACTERISTICS
Datasheet
Standard
Professional
Reverse characteristics

11. 4.1 Comparison Result
Voltage, Current, and Power of D1 in Boost Converter Circuit
Professional Model
Time
119.980ms 119.985ms 119.990ms 119.995ms
rms(V(U2:A,U2:K)*I(U2:A))
20mW
30mW
35mW
40mW
SEL>>
(119.990m,28.917m)
I(U2:A)
-100mA
0A
100mA
V(U2:A,U2:K)
-10V
-5V
0V
Time
119.980ms 119.985ms 119.990ms 119.995ms
rms(V(D1:A,D1:c)*I(D1))
20mW
30mW
40mW
SEL>>
(119.990m,29.955m)
I(D1)
-100mA
0A
100mA
V(D1:A,D1:c)
-10V
-5V
0V
Standard Model
PD(rms) = 28.917mW
PD(rms) = 29.955mW
V(AK)
I(AK)
V(AK)
I(AK)

12. L1
150u
1 2
CLP
100p
Rf
1000k
Rsr
180k
Cs
4.7uF
IC = 0
0
0
U1
NJM2377
FOSC = 150K
-IN
FB
GND
OUT
V+
CS
CT
REF
RL
180
Q1
Q2SD2623
U2RB055L-40
OUT
Rt
24k
Ct
470p
IC = 0
0
CIN
220uF
V+
0
Rsf
160k
R1
9.1k
R2
150k
Rs
{ESR}
0
PARAMETERS:
ESR = 103m
V2
5Vdc
COUT
220u
5.Power Switch: Q1
Panasonic’s NPN Transistor: 2SD2623
BJT
Power
Switch

13. 5.1 Power Switch: Q1
PC, IB, VC, and IC Simulation Result
IB
VC
IC
PC

14. 5.2 Power Switch: Q1
Power Stage Device Stress Analysis
Parameter Start-Up Steady-State
Absolute Maximum
Ratings
VCE (V)
9.322
(46.61% of VCEO)
9.368
(46.84% of VCEO)
VCEO=20V
IC (A)
0.287
(57.4% of ICmax)
0.093
(18.6% of ICmax)
ICmax.=0.5A