an1915

Application Note 1915
Author: Oscar Mansilla
ISL70003SEH iSim:PE Model
Introduction
license. If the Licensee does not accept these terms,
permission to use the model is not granted.
The ISL70003SEH is a radiation and SEE hardened
synchronous buck regulator capable of operating over an input
voltage range of 3.0V to 13.2V. The ISL70003SEH uses voltage
mode control architecture with feed-forward and switches at a
selectable frequency of 500kHz or 300kHz. Loop
compensation is externally adjustable to allow for an optimum
balance between stability and output dynamic performance.
With integrated MOSFETs and class leading radiation
performance, this highly efficient single chip power solution is
an ideal choice in many space applications.
The Licensee may not sell, loan, rent, or license the
macro-model, in whole, in part, or in modified form, to anyone
outside the Licensee’s company. The Licensee may modify the
macro-model to suit his/her specific applications, and the
Licensee may make copies of this macro-model for use within
their company only.
This macro-model is provided “AS IS, WHERE IS, AND WITH NO
WARRANTY OF ANY KIND EITHER EXPRESSED OR IMPLIED,
INCLUDING, BUT NOT LIMITED TO, ANY IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE.”
The iSim:PE model for the ISL700003SEH was developed to
help system designers evaluate the operation of this IC prior to
or in conjunction with proto-typing a system design. This model
accurately simulates typical performance characteristics such
as loop analysis, transient analysis, start-up and steady state
analysis at room temperature (+25°C).
In no event will Intersil be liable for special, collateral,
incidental, or consequential damages in connection with or
arising out of the use of this macro-model. Intersil reserves the
right to make changes to the product and the macro-model
without prior notice.
Reference Documents
Schematic File
• ISL70003SEH Data Sheet; FN8604
The schematic file: ISL70003SEH.sxsch is the main
application schematic to be used in the iSim:PE simulator. The
schematic mimics the evaluation board and is designed for
12V input to 3.3V output conversion, see Figure 1. The
simulation profile is set up to run an AC and 3A load transient
test. Figure 2 through 13 show a comparison of the simulation
results for various operating conditions versus actual bench
validation data. For more information on iSim:PE visit the iSim
online home page.
• ISL70003SEH SMD 5962-14203
License Statement
The information in this macro-model is protected under the
United States copyright laws. Intersil Corporation hereby grants
users of this macro-model hereto referred to as “Licensee”, a
nonexclusive, nontransferable license to use this model as
long as the Licensee abides by the terms of this agreement.
Before using this macro-model, the Licensee should read this
22k
R2
USE_IC=1
X=5
IC=12
CIN2
L=1.44n
RSHUNT=10Meg
RESR=29.1m
C=1u
100k
R16
51k
R4
BUFOUT
3k
R10
R15
370p
7.15k
C15
IC=1
PORVIN
DVDD
EN
AVDD
EN
BUFOUT
BUFINP
10k
PGOOD
10n
BUFINP
PVIN
C16
IC=0
BUFINN
USE_IC=1
X=4
IC=12
CIN1
L=2.1n
RSHUNT=100K
RESR=6m
C=100u
RTCT
12
V1
PGOOD
IMON
U1
C9
10n
VOUT
R11
VREFA
10
R1
LX3
C8
IC=5
470n
VREFOUTS
C1
1n
LX4
C10
IC=5
470n
LX5
VREFD
LX6
C11
IC=5
SYNC
ISL70003SEH
SYNC
49.9
IC=1.5
C12
USE_IC=1
X=3
IC=3.3
COUT1
L=2.1n
RSHUNT=100K
RESR=6m
C=150u
USE_IC=1
X=1
IC=3.3
COUT2
L=1.44n
RSHUNT=10Meg
RESR=29.1m
C=1u
ESR=5m
IC=3.3
100n
COUT3
1x
LX8
LX9
SS
LX10
100n
FB
OCSETA
R9
VERR
51.1k
C5
IC=-430m
12p
6.8n
C13
REF
C7
220n
IC=600m
4.02k
R13
NI
4.02k
PGND
AGND
DGND
SGND
DE
NC
SEL2
SEL1
FSEL
R14
TCLK
TDO
TSTRIM
TDI
OCSETB
TPGM
C6
IC=-430m
3.3u
LX7
R12
2.7n
D1
LX2
470n
DCR=5m
L1
IC=1
LX1
RISE=10u
DELAY=10u
VFINAL=0
VSTART=0
VEN
RSRC=1m
EN
S1
RON=1
ROFF=100Meg
6.8n
C14
R6
5.49k
R7
25k
R8
1n
357
C4
FIGURE 1. ISL70003SEH iSIM:PE APPLICATION SCHEMATIC
January 22, 2014
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CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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Application Note 1915
Simulation Performance Curves
12
ENABLE, 5V/DIV
x axis = 1ms/DIV
10
INDUCTOR CURRENT, 2A/DIV
INDUCTOR CURRENT, 2A/DIV
8
ENABLE, 2V/DIV
6
OUTPUT VOLTAGE, 2V/DIV
OUTPUT VOLTAGE, 2V/DIV
4
2
PGOOD, 2V/DIV
PGOOD, 10V/DIV
00
FIGURE 2. CHARACTERIZED SOFT-START WITH 6A LOAD
1
2
3
4
5
6
7
8
FIGURE 3. SIMULATED SOFT-START WITH 6A LOAD
LXx VOLTAGE, 2V/DIV
10
8
6
4
2
-0
INDUCTOR CURRENT, 200mA/DIV
6.8
LXx VOLTAGE, 5V/DIV
6.6
6.4
6.2
6
5.8
5.6
5.4
OUTPUT VOLTAGE, 10mV/DIV
3.36
INDUCTOR CURRENT, 1A/DIV
3.359
3.358
3.357
OUTPUT VOLTAGE, 20mV/DIV
3.356
0
1
2
3
4
5
6
7
8
9
FIGURE 5. SIMULATED FREQUENCY RESPONSE vs GAIN
FIGURE 4. CHARACTERIZED FREQUENCY RESPONSE vs GAIN
INDUCTOR CURRENT, 1A/DIV
INDUCTOR CURRENT, 2A/DIV
7
6
5
4
3
2
1
-0
Y1
3.55
3.5
3.45
OUTPUT VOLTAGE, 50mV/DIV
3.4
3.35
OUTPUT VOLTAGE, 50mV/DIV
3.3
3.25
FIGURE 6. CHARACTERIZED 6A LOAD TRANSIENT RESPONSE
2
0
1
2
3
4
5
6
7
8
FIGURE 7. SIMULATED 6A LOAD TRANSIENT RESPONSE
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January 22, 2014
Application Note 1915
Simulation Performance Curves (Continued)
12
10
8
6
LXx VOLTAGE, 5V/DIV
4
2
LXx VOLTAGE, 2V/DIV
-0
Y1
INDUCTOR CURRENT, 5A/DIV
PGOOD, 2V/DIV
10
8
OUTPUT VOLTAGE, 2V/DIV
6
OUTPUT VOLTAGE, 2V/DIV
4
2
INDUCTOR CURRENT, 2A/DIV
PGOOD, 10V/DIV
-0
90
100
110
120
FIGURE 9. SIMULATED OVERCURRENT RESPONSE
FIGURE 8. CHARACTERIZED OVERCURRENT RESPONSE
12
10
8
6
LXx VOLTAGE, 2V/DIV
4
2
LXx VOLTAGE, 5V/DIV
-0
10
8
INDUCTOR CURRENT, 10A/DIV
6
INDUCTOR CURRENT, 2A/DIV
4
2
-0
OUTPUT VOLTAGE, 2V/DIV
3
OUTPUT VOLTAGE, 0.5V/DIV
2.5
2
1.5
1
SS VOLTAGE, 0.5V/DIV
0.5
SS VOLTAGE, 2V/DIV
-00
10
20
GAIN
0
150
60
100
40
50
20
0
-20
-50
-40
-60
-80
10
100
1k
10k
100k
1M
40
200
150
PHASE SIM
100
50
GAIN SIM
0
0
-20
-50
-100
-40
-100
-150
-60
-150
-200
-80
10
PHASE (°)
GAIN (dB)
40
80
GAIN (dB)
PHASE
200
PHASE (°)
60
30
FIGURE 11. SIMULATED HICCUP RESPONSE IN OCP
FIGURE 10. CHARACTERIZED HICCUP RESPONSE IN OCP
80
20
-200
100
1k
10k
100k
1M
FREQUENCY (Hz)
FREQUENCY (Hz)
FIGURE 12. CHARACTERIZED LOOP RESPONSE
FIGURE 13. SIMULATED LOOP RESPONSE
Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is
cautioned to verify that the Application Note or Technical Brief is current before proceeding.
For information regarding Intersil Corporation and its products, see www.intersil.com
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