mm1149

HFA1149 SPICE Macromodel (CFA)
TM
Application Note
March 1997
MM1149
Introduction
The HFA1149 is a high speed, low power current feedback
amplifier with output Enable/Disable capability. The macromodel for the HFA1149 is PSPICE (registered trademark of
MicroSim Corp.) compatible, and may be compatible with
other simulation programs as well. The model file is in ASCII
format and may be viewed/edited with any text editor. For
this model to run properly in PSPICE be sure to set
ITL4 = 100 and turn on STEPGMIN; otherwise, convergence
errors may occur.
All models require a trade-off between accuracy and complexity (simulation time). Intersil's models emulate the nominal performance of a typical device, and are designed to
match the typical performance curves in the device data
sheet.
SPICE simulations should not be considered a substitute for
breadboarding a circuit; rather, they should be used to select
preliminary component values and to verify the validity of a
design approach.
Do not rely on simulations to predict device performance
when deviating from the operating conditions specified in the
data sheet (e.g., just because the model works with ±1V
supplies, don't assume that the actual amplifier does).
Instead, refer to the data sheet performance curves, or call
the factory for assistance (321-724-7143).
The HFA1149 model is configured as a subcircuit for easy
incorporation into larger circuit files. When using PSPICE,
call a subcircuit from the top level circuit file by adding a .LIB
statement to point to the file containing the subcircuit (e.g.
.lib c:\models\hfa1149.cir), and by including a subcircuit call
of the following form:
xname
(e.g., x22
+IN -IN V+
model
V- DIS THR POL OUT name
106 107 109 110 111 112 113 108 op amp)
Note that the node order in the subcircuit call follows the
industry standard, and the order is also documented in the
comment section at the beginning of the model file.
Model Description
The macromodel schematic is shown in Figure 1, and the
PSPICE listing for the macromodel follows. The HFA1149
model is basically the HFA1109 amplifier model with circuitry
around it to implement the output Enable/Disable function.
1
The model topology consists of three main functional sections: a buffer between the two input pins, an output section
between the inverting input pin and the output pin, and an
enable section.
The input buffer section is a unity gain buffer with additional
components added to model the critical characteristics of
the actual buffer. Of these additional components, some
are used to model both the slew limiting of the inverting
input and the fractional step feed-through from the noninverting input to the inverting input. Other elements model
the voltage and current limiting of the inverting input. The
bias current of the non-inverting input and the high
frequency voltage gain are also accounted for in the input
buffer section.
The output section is a transimpedance amplifier
constructed from four stages: current probe, mid stage,
frequency transfer, and output drive. The current probe
stage monitors the current through the inverting input pin
and also models the input offset voltage. The mid stage is
used for the bias current of the inverting input and for power
supply gains. The frequency transfer block consists of two
poles and two zeros for modeling the high frequency openloop transimpedance gain. The output drive stage accounts
for several characteristics including: the output slew limits
and resulting transimpedance gain bandwidth product, the
saturation delay times, and the voltage and current limiting
at the output.
The enable section accurately models the turn-on/turn-off
times, disabled Icc, and off-isolation. This section operates
according to the voltage level at the disable input pin which
controls the input/output impedance and the Enable/Disable
time of the amplifier. The internal bias current of the input
buffer section is also set by the enable section shown at the
bottom of Figure 1C. As a result, high impedance states are
achieved at the two input pins whenever the amplifier is disabled. The polarity function was implemented with the circuitry at the bottom of Figure 1B and the threshold pin
functionalities were modeled with the circuitry at the top of
Figure 1B.
In addition to the three main functional sections, smaller constructs and individual components are used to model other
important amplifier characteristics. Specifically, one section
is used to capture the change in the voltage limits of the output as a function of the current through the inverting input.
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 321-724-7143 | Intersil (and design) is a trademark of Intersil Americas Inc.
Copyright © Intersil Americas Inc. 2002. All Rights Reserved
Application Note MM1149
V+
DIS. BIAS
CIRCUITRY
C10
HFA1109
MACROMODEL
IN+
IN-
+
-
OUT
C18
S5, S13, S8
DIS. BIAS
CIRCUITRY
S6, S17, S9
POLARITY
POLARITY,
THRESHOLD,
AND TIMING
CIRCUITRY
DIS
THRESHOLD
VCONTROL VOLTAGE
FIGURE 1A. HFA1149 MACROMODEL SCHEMATIC
THRESHOLD CIRCUITRY
DIGITAL THRESHOLD VOLTAGE
THRESHOLD
+
E_SUM2
0.632*THRESHOLD + .079*(V-) +.291*(V+) - 1.6
POLARITY CIRCUITRY
POLARITY
S19
V+
R69
0-5V INVERTING
LIMITING AMP
R71
G=1
DIS
+
-
E_GAIN1
R72
E_EAMP2,
E_GLIMIT3
S20
∑
R68
E_SUM5
DIGITAL THRESHOLD
VOLTAGE
FIGURE 1B. HFA1149 MACROMODEL ADDITIONAL SUPPORT CIRCUITS
2
NORM./INV. DISABLE
Application Note MM1149
TIMING CIRCUITRY
D2
R45
E_AMP4,
E_GLIMIT5
NORM./INV. DISABLE
D1
D4
+
-
R43
R49
CONTROL VOLTAGE
C17
DIGITAL THRESHOLD
VOLTAGE
C11
R50
DISABLE BIAS CIRCUITRY
V-
V+
G3
I1
G2
I2
FIGURE 1C. HFA1149 MACROMODEL ADDITIONAL SUPPORT CIRCUITS
+
-
DIPM
V+
+ INPUT BIASING,
LOADING, AND
STEP-FEEDTHROUGH
VIPM
DINM
+
-
VINM
DVPM
RBW
CBW
GBW
R100
DVNM
+
RP1
L100
R850
+ IN
SIMPLE POLE/
ZERO PAIR(S)
GBW POLE
C100
EP1
RZ1
+
-
CP1
CPNM
-
GIPM
V-
+
-
RPM
RSN
AMPLIFIER OUTPUT STAGE
DSP
GPM
RAM
+
DSN
GPZ
EVC
GRDM
DHM
RDM
VSP
+
-
DLM
+
-
ECCM
DPM
+
-
EEEM
DNM
+
-
EXPM
EXNM
VMI
SLEW LIMITING
AND GAIN
STAGES
R2
-
TO GMI,
GCC, GPC
CC
F2
R200
C200
FIGURE 1D. HFA1149 MACROMODEL INPUT STAGE
3
+
L200
-IN
G2
+
-
CMI
Application Note MM1149
FREQUENCY TRANSFER
(SIMPLE POLE ZERO PAIRS)
MID-STAGE WITH BIASING AND
POWER SUPPLY DEPENDENCE
FROM VMI
C1A
C2A
RZ1A
RZ2A
RT
GPC
GCC
GMI
R1A
GMI2
GMI3
R2A
GINA
CC
G2A
AMPLIFIER OUTPUT DRIVE WITH LIMITING
RA
MOUT
R2
RD
DH
GRD
GRDP
GOUTA
G2P
+
ECC
DL
DP
+
-
+
-
+
EXP
EEE
FIGURE 1E. HFA1149 MACROMODEL OUTPUT STAGE
POWER SUPPLY
CURRENT GENERATOR
HIGH FREQUENCY
SUPPLY GAIN TO OUTPUT
V+
GH
IH
RFH
GFH
RFL
GFL
GPS
IL
DPS
V-
FIGURE 1F. HFA1149 MACROMODEL ADDITIONAL SUPPORT CIRCUITS
4
DN
EXN
Application Note MM1149
HFA1149 SPICE Macro Model Listing
* Copyright (C) 1997 Intersil Corp.
* Rev. 2/24/97, Be sure to set ITL4=100 and turn on STEPGMIN for PSpice to simulate properly.
*Subcircuit Call Order: +IN -IN V+ V- DISABLE THRESHOLD POLARITY OUT
.SUBCKT HFA1149 + - V+ V- DIS_ THR POL OUT
X_U10
1 2 V+ V- 3 HFA1109AMP
S_S5
5 OUT in2 4 Switch2
RS_S5
in2 4 1G
S_S6
7 - in2 6 Switch2
RS_S6
in2 6 1G
V_V38
4 0 .5
V_V39
6 0 .05
S_S8
9 2 8 in2 Switch2
RS_S8
8 in2 1G
V_V42
8 0 2.0
S_S9
11 0 10 in2 Switch2
RS_S9
10 in2 1G
V_V43
10 0 2.0
D_D1
12 13 Dlow
V_V45
14 0 .5
D_D2
15 12 Dlow
D_D3
14 16 Dlow
E_EAMP1
17 0 VALUE = { V(18, 19)*1 }
D_D4
20 21 Dlow
S_S13
3 5 in2 22 Sout4
RS_S13
in2 22 1G
V_V52
22 0 .1
V_V54
23 0 .5
S_S17
7 2 in2 23 Sout4
RS_S17
in2 23 1G
V_V59
24 0 .5
I_I1
0 V+ DC 6.6mA
I_I2
0 V- DC -6.6mA
R_R40
9 3 250
R_R42
11 25 90
R_R43
13 18 13k
C_C11
14 18 5p
R_R44
14 18 100k
C_C12
18 15 1p IC=0
R_R45
15 18 10
R_R46
16 18 1
R_R49
in2 21 10
R_R50
in2 0 1.5k
C_C17
0 in2 5p
R_R51
24 18 10e6
C_C10
OUT 5 .025p
C_C18
2 - .025p
G_G2
0 V+ 12 0 -1.32e-3
G_G3
0 V- 12 0 1.32e-3
E_SUM2
19 0 VALUE {.291*V(26)+.079*V(27)+.632*V(THR)+V(28)}
V_V73
28 0 -1.6
S_S18
2 25 29 0 Switch6
RS_S18
29 0 1G
S_S19
30 31 POL 0 Sdisable
RS_S19
POL 0 1G
S_S20
33 34 32 POL Sdisable
RS_S20
32 POL 1G
E_SUM5
12 0 VALUE {V(30)+V(33)}
R_R68
0 33 1k
R_R69
0 30 1k
5
Application Note MM1149
HFA1149 SPICE Macro Model Listing
(Continued)
V_CONST2
32 0 DC 3.000
E_GAIN1
35 0 VALUE {1 * V(DIS_)}
R_R71
DIS_ V+ 50k
R_R72
0 DIS_ 5e6
R_R73
POL V+ 50k
R_R75
THR 36 50k
V_V84
36 0 3
R_R76
0 THR 5e6
R_R77
0 POL 5e6
R_R80
26 V+ 1
R_R81
V- 27 1
R_R82
0 26 5e6
R_R83
27 0 5e6
E_EAMP2
37 0 VALUE = { V(35, 19)*-1 }
E_GLIMIT3
34 0 VALUE {LIMIT(V(37)*50,0,5)}
R_R84
0 34 1k
E_GLIMIT2
20 0 VALUE {LIMIT(V(17)*50,0,5)}
E_ABS4
29 0 VALUE {ABS(V(1))}
R_R86
+1 1
R_R87
1 0 10e6
E_EAMP4
38 0 VALUE = { V(35, 19)*1 }
E_GLIMIT5
31 0 VALUE {LIMIT(V(38)*50,0,5)}
.model Dlow D N=.01
.model Switch6 VSWITCH Roff=300 Ron=1 von=1.0 voff=1.1
.model Sdisable VSWITCH von=2 voff=1
.model Sout4 VSWITCH Ron=.1 Roff=10k von=3.5 voff=.1
.model Switch2 VSWITCH Roff=10e6 Ron=.1 von=.2 voff=.1
.ENDS HFA1149
.SUBCKT HFA1109AMP 106 107 109 110 108
L200 111 107 +1.60000000E-05
R200 111 107 +1.18000000E+02
C200 107 111 +1.30000000E-12
L100 101 850 +5.00000000E-07
R100 101 106 +4.50000000E+03
C100 101 0 +3.1000000000E-13
R850 106 850 75
VMI 111 112 +0.00000000E+00
GINIH 0 113 109 0 1M
R1IH 113 0 1K
C1IH 113 0 +1.59159637E-13
R2IH 114 0 -1.00000000E+03
RY2IH 114 115 +1.00000000E+03
C2IH 115 0 +4.82301931E-11
G2IH 0 114 113 0 -1.00000000E-03
GOUTIH 116 0 114 0 -1.00000000E+00
RPGIH 116 0 1
GINIL 0 117 110 0 1M
R1IL 117 0 1K
C1IL 117 0 +1.59159637E-13
R2IL 118 0 -1.00000000E+03
RY2IL 118 119 +1.00000000E+03
C2IL 119 0 +8.37682301E-11
G2IL 0 118 117 0 -1.00000000E-03
GOUTIL 120 0 118 0 -1.00000000E+00
RPGIL 120 0 1
EVC 121 112 POLY 4 106 0 111 0 116 0 120 0 -2.76409908E-03
++2.23336645E-04 +2.23336645E-04 +8.08400638E-05 -5.27513353E-04 0 0
+-7.70216445E-06 +7.70216445E-06 0 -7.70216445E-06 +7.70216445E-06
6
Application Note MM1149
HFA1149 SPICE Macro Model Listing
(Continued)
++7.70216445E-06 0 -7.70216445E-06
CMI 111 0 +1.00000000E-15
FPM 122 0 VMI +1.00000000E+00
DMP 122 123 DIM
DMM 124 122 DIM
.MODEL DIM D IS=1E-16 N=.001
GCC 122 0 POLY 4 106 0 111 0 109 0 110 0 +6.58458515E-06 +4.90772982E-07
++4.90772982E-07 -1.08867981E-07 +1.09041394E-06 0 0 +1.74372872E-08
+-1.74372872E-08 0 +1.74372872E-08 -1.74372872E-08 -1.74372872E-08 0
++1.74372872E-08
VMP 123 0 0
VMM 0 124 0
FMI 0 103 POLY 2 VMP VMM 0 -9.00000000E-03 +9.00000000E-03
RT 103 0 +1.00000000E+00
GPC 0 103 POLY 2 109 0 110 0 0 +0.00000000E+00 +0.00000000E+00
GINA 0 125 103 0 1M
R1A 125 0 1K
C1A 125 0 +1.59159637E-13
G2A 0 126 125 0 1M
R2A 126 0 1K
C2A 126 0 +5.89480137E-14
G3A 0 127 126 0 1M
R3A 127 0 1K
C3A 127 0 +3.97899093E-15
R4A 128 0 +1.00000000E+03
RY4A 128 129 -1.00000000E+03
C4A 129 0 +2.65266062E-14
G4A 0 128 127 0 +1.00000000E-03
R5A 130 0 +1.00000000E+03
RY5A 130 131 -1.00000000E+03
C5A 131 0 +2.27370910E-14
G5A 0 130 128 0 +1.00000000E-03
GI6A 0 132 130 0 +2.00000000E-03
R6A 132 0 +1.00000000E+03
C6A 132 0 +5.82692545E-14
G6A 0 132 133 0 -1.00000000E-03
GY6A 0 133 132 0 1M
CY6A 133 0 +3.39618104E-13
RY6A 133 0 1K
RO6A 0 134 1e9
R7A 134 135 +5.02412563E+05
GI7A 0 134 133 0 +1.99000000E-06
C7A 134 135 +4.28082941E-14
G7A 0 135 136 0 -1.00000000E-03
GY7A 0 136 135 0 1M
CY7A 136 0 +1.08077511E-14
RY7A 136 0 +1.00000000E+04
GZ7A 0 137 134 0 -1.00000000E-06
RZ7A 137 0 -1.00000000E+06
RC7A 137 138 1000001
CZ7A 138 0 +2.15074248E-14
GOUTA 105 0 137 0 -1.00000000E+00
GRD 102 0 105 0 +4.27868630E+00
GINOH 0 139 109 0 1M
R1OH 139 0 1K
C1OH 139 0 +1.59159637E-13
GOUTOH 140 0 139 0 -1.00000000E+00
RDPH 140 0 1
GINOL 0 141 110 0 1M
7
Application Note MM1149
HFA1149 SPICE Macro Model Listing
(Continued)
R1OL 141 0 1K
C1OL 141 0 +1.59159637E-13
GOUTOL 142 0 141 0 -1.00000000E+00
RDPL 142 0 1
G2P 0 105 POLY 2 140 0 142 0 0 +1.38629436E-07 +1.38629436E-07
GRDP 102 0 POLY 2 140 0 142 0 0 -2.20878759E+00 -2.20878759E+00
R2 105 0 +3.60673760E+06
CC 105 102 +1.00000000E-14
RD 102 0 +7.20000000E+00
RA 102 108 +1.07000000E+01
DH 102 104 DH +1.00000000E+00
DL 100 102 DL +1.00000000E+00
.MODEL DH D IS=+1.99173432E-14 N=.2
.MODEL DL D IS=+1.28277200E-14 N=.2
ECC 104 0 POLY 2 109 0 143 0 -1.19000000E+00 1 1
EEE 100 0 POLY 2 110 0 144 0 +1.25000000E+00 1 1
FCC 0 143 POLY 1 VMI +9.96717960E-05 +1.33000000E-01
RCC 143 0 1K
CRC 143 0 +1.00000000E-10
D55 143 0 DLIMVO
FEE 0 144 POLY 1 VMI -1.63095844E-04 +1.63000000E-01
REE 144 0 1K
CRE 144 0 +1.00000000E-10
D66 0 144 DLIMVO
.MODEL DLIMVO D N=.01 IS=1E-20
DP 102 145 DCL +1.00000000E+00
EXP 145 0 POLY 2 102 0 108 0 0 +3.20491434E-01 +6.77833280E-01
DN 146 102 DCL +1.00000000E+00
EXN 146 0 POLY 2 102 0 108 0 0 +1.86957037E-01 +8.11038456E-01
.MODEL DCL D IS=1E-9 N=1
IPS 109 110 +9.40000000E-03
GPS 147 0 102 108 +9.34579439E-02
GH 109 147 POLY 1 147 110 +1.61343210E-02 -3.22686420E-02 +2.42014815E-02
+-8.06716049E-03 +1.00839506E-03
DPS 147 110 DPS
.MODEL DPS D IS=1E-16 N=+3.40072108E+00
DVPM 106 109 DLIMM
GIPM 106 0 POLY 4 106 0 111 0 109 0 110 0 -5.30320265E-06 +1.02950000E-05
+-9.70500000E-06 -2.95000000E-07 -2.95000000E-07
DVNM 110 106 DLIMM
VIPM 148 149 0
DIPM 106 148 DLIMM
DINM 150 106 DLIMM
VINM 149 150 0
CPNM 149 0 +1.00000000E-15
RINM 106 101 +1.00000000E+04
CINM 101 0 +9.90000000E-14
GINI 0 151 106 0 1M
R1I 151 0 1K
C1I 151 0 +1.90382341E-13
GI2I 0 152 151 0 +1.12250000E-03
R2I 152 0 +8.16326531E+03
C2I 152 0 +9.96948751E-14
G2I 0 152 153 0 -1.00000000E-03
GY2I 0 153 152 0 1M
CY2I 153 0 +1.61679590E-12
RY2I 153 0 1K
G3I 0 154 153 0 1M
R3I 154 0 1K
8
Application Note MM1149
HFA1149 SPICE Macro Model Listing
C3I 154 0 +7.76388474E-13
G4I 0 155 154 0 1M
R4I 155 0 1K
C4I 155 0 +5.30532124E-14
G5I 0 156 155 0 1M
R5I 156 0 1K
C5I 156 0 +5.30532124E-14
R6I 157 0 -1.00000000E+03
RY6I 157 158 +1.00000000E+03
C6I 158 0 +1.76844041E-13
G6I 0 157 156 0 -1.00000000E-03
R7I 159 0 -1.00000000E+03
RY7I 159 160 +1.00000000E+03
C7I 160 0 +8.37682301E-14
G7I 0 159 157 0 -1.00000000E-03
R8I 161 0 -1.00000000E+03
RY8I 161 162 +1.00000000E+03
C8I 162 0 +8.37682301E-14
G8I 0 161 159 0 -1.00000000E-03
R9I 163 0 -2.00000000E+03
RZ9I 163 164 +3.00000000E+03
C9I 164 0 +5.30532124E-14
G9I 0 163 161 0 -5.00000000E-04
R10I 165 0 -2.00000000E+03
RZ10I 165 166 +3.00000000E+03
C10I 166 0 +5.30532124E-14
G10I 0 165 163 0 -5.00000000E-04
R11I 167 0 -2.00000000E+03
RZ11I 167 168 +3.00000000E+03
C11I 168 0 +5.30532124E-14
G11I 0 167 165 0 -5.00000000E-04
R12I 169 0 -2.00000000E+03
RZ12I 169 170 +3.00000000E+03
C12I 170 0 +5.30532124E-14
G12I 0 169 167 0 -5.00000000E-04
R13I 171 0 -2.00000000E+03
RZ13I 171 172 +3.00000000E+03
C13I 172 0 +5.30532124E-14
G13I 0 171 169 0 -5.00000000E-04
R14I 173 0 -2.00000000E+03
RZ14I 173 174 +3.00000000E+03
C14I 174 0 +5.30532124E-14
G14I 0 173 171 0 -5.00000000E-04
R15I 175 0 -2.00000000E+03
RZ15I 175 176 +3.00000000E+03
C15I 176 0 +5.30532124E-14
G15I 0 175 173 0 -5.00000000E-04
R16I 177 0 -2.00000000E+03
RZ16I 177 178 +3.00000000E+03
C16I 178 0 +5.30532124E-14
G16I 0 177 175 0 -5.00000000E-04
R17I 179 0 -2.00000000E+03
RZ17I 179 180 +3.00000000E+03
C17I 180 0 +5.30532124E-14
G17I 0 179 177 0 -5.00000000E-04
R18I 181 0 -2.00000000E+03
RZ18I 181 182 +3.00000000E+03
C18I 182 0 +5.30532124E-14
G18I 0 181 179 0 -5.00000000E-04
9
(Continued)
Application Note MM1149
HFA1149 SPICE Macro Model Listing
(Continued)
GOUTI 183 0 181 0 -1.00000000E+00
GPMM 183 0 184 0 +1.00200401E+00
RPMM 183 0 +1.12142857E+11
VSPM 185 0 +9.64285714E-01
DSPM 183 185 DLIMM
VSNM 0 186 +1.03571429E+00
DSNM 186 183 DLIMM
.MODEL DLIMM D N=0.01
G2M 187 0 POLY 2 183 0 184 0 0 +1.00000000E-03 +1.00000000E-03
F2M 187 0 POLY 2 VIPM VINM 0 +1.25000000E+02 -1.25000000E+02
R2M 187 0 1
CCM 187 184 +1.78571429E-12
G4M 184 0 187 0 1K
R4M 184 0 1
GRDM 0 188 184 0 +1.14652603E-02
RDM 188 0 +8.72200000E+01
RAM 188 121 +1.78000000E+00
DHM 188 189 DVM +1.00000000E+00
DLM 190 188 DVM
.MODEL DVM D IS=1E-16 N=.2
ECCM 189 0 POLY 1 109 0 -2.83000000E+00 1.0
EEEM 190 0 POLY 1 110 0 +2.83000000E+00 1.0
DPM 188 191 DCLM +1.00000000E+00
EXPM 191 0 POLY 4 188 0 121 0 109 0 110 0 0 -5.28714965E+01 +5.38520064E+01
+ +9.74504713E-03 +9.74504713E-03
DNM 192 188 DCLM +1.00000000E+00
EXNM 192 0 POLY 2 188 0 121 0 0 -8.28974671E+01 +8.38903217E+01
.MODEL DCLM D IS=1E-20 N=1
FPS 0 147 VMI 1
.ENDS HFA1109AMP
HFA1149 Macro Model Performance
The model is designed for operation at ±5V. Beware, the
model does not simulate various breakdown conditions
such as exceeding the maximum ratings, but it does have
input limiting. The model does not include input voltage or
current noise, or temperature effects. The poles and zeros
of the transimpedance frequency transfer section have
been located with great care to insure that the performance
for three different gains is matched closely to the curves
given in the data sheet. Also, the pole/zero placement
insures that the transient response matches that shown in
the data sheet.
Intersil Application Note AN9523 titled “Evaluation
Programs For SPICE Op Amp Models” was used as a
guideline for evaluating the HFA1149 performance.
Figure 2 shows the AC transfer function for gains of 2, 1,
and -1. In the gain of two configuration the peaking is 0dB
versus the 0dB of peaking shown in the data sheet. The
gain of two simulated -3dB bandwidth is 430MHz compared
to the data sheets 450MHz. This is quite a good correlation
between the model and the data sheet. Similarly, the gains
of 1 and -1 have -3dB bandwidths of 325MHz and 390MHz
which closely match the 330MHz and 375MHz listed in the
data sheet. The large signal responses for gains of 1 and 2
are shown in Figure 3 and the response for a gain of -1 is
shown in Figure 4. Figure 3 shows an 1150V/µs gain of 2
10
slew rate versus the data sheets 1100V/µs, and it shows a
600V/µs gain of 1 slew rate versus the data sheet’s
575V/µs. Figure 4 shows a 2900V/µs slew rate for the gain
of -1 versus the data sheet’s 2600V/µs. Again the
correlation between the model and the data sheet is quite
good. The small signal pulse responses are shown in
Figures 5 and 6. The rise time, fall time, and overshoot can
be read off these waveforms. Figure 7 is a graph of the offisolation which correlates closely to the data sheet’s -54dB
at 30MHz and -64dB at 10MHz. Figures 8 and 9
correspond to the large signal and small signal
enable/disable time. The enable and disable times are
accurately modeled but the enable overshoot does not
match the data sheet specifications.
Application Note MM1149
3.0
3.0
2.0
2.0
INPUT/OUTPUT VOLTAGE (V)
OUTPUT WITH A V = 2
GAIN (dB)
1.0
0
AV = 2
-1.0
AV = 1
-2.0
AV = -1
-3.0
10
30
100
300
1.0
OUTPUT WITH
AV = 1
0
-1.0
-2.0
-3.0
700
INPUT
0
5
10
FREQUENCY (MHz)
FIGURE 2. HFA1149 AC TRANSFER FUNCTIONS
300
2.0
INPUT/OUTPUT VOLTAGE (mV)
INPUT/OUTPUT VOLTAGE (V)
25
FIGURE 3. HFA1149 NON-INVERTING LARGE SIGNAL
PULSE RESPONSE
3.0
INPUT
1.0
0
OUTPUT WITH
AV = -1
-1.0
-2.0
-3.0
20
15
TIME (ns)
OUTPUT WITH AV = 2
200
OUTPUT WITH AV = 1
100
INPUT
0
-100
-200
-300
0
5
15
10
20
25
0
4
8
12
16
20
TIME (ns)
TIME (ns)
FIGURE 4. HFA1149 INVERTING LARGE SIGNAL PULSE
RESPONSE
FIGURE 5. HFA1149 NON-INVERTING SMALL SIGNAL PULSE
RESPONSE
-40
200
INPUT
-50
100
0
OFF-ISOLATION (dB)
INPUT/OUTPUT VOLTAGE (mV)
300
OUTPUT WITH
AV = -1
-100
-200
-60
-70
-80
-300
0
5
10
15
20
TIME (ns)
25
-90
1.0
3.0
10
30
FREQUENCY (MHz)
FIGURE 6. HFA1149 INVERTING SMALL SIGNAL PULSE
RESPONSE
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FIGURE 7. HFA1149 OFF-ISOLATION WITH AV = 2
100
5.0
400
DISABLE INPUT
DISABLE INPUT/
AMPLIFIER OUTPUT VOLTAGE (V)
DISABLE INPUT/AMPLIFIER OUTPUT (V)
Application Note MM1149
4.0
3.0
OUTPUT
2.0
1.0
0
-1.0
0
10
20
30
40
50
60
TIME (ns)
FIGURE 8. HFA1149 LARGE SIGNAL ENABLE/DISABLE TIME
WITH AV = 2 AND VIN = 1V
DISABLE INPUT
DISABLE INPUT
300
OUTPUT
200
100
0
0
10
20
30
40
50
60
FREQUENCY (MHz)
FIGURE 9. HFA1149 SMALL SIGNAL ENABLE/DISABLE TIME
WITH AV = 2 AND VIN = 0.1V
Summary
License Statement
The macromodel performs well for both the DC and AC
parameters. It is a fraction of a dB off for some AC tests, but
this is acceptable for an approximation. At least the model
has peaking where the op amp has peaking, and the
response for different gains is modeled correctly. The model
is just an approximation! It cannot predict performance to a
few percent; especially when one considers that the circuit
layout parameters have such a large effect on high frequency performance. The model will not predict the actual
performance in many circumstances such as non-linearities,
limits of performance, or extended range operation. Only
testing will confirm performance out of the normal operating
range, and all circuits should be tested to confirm the
model’s predictions.
The information in these SPICE macromodels (models) is protected by the United States copyright laws. Intersil Corporation
(Intersil) hereby grants users of these models, herein referred
to as licensee, a nonexclusive, nontransferable license to use
these models as long as the licensee abides by the terms of
this agreement. Before using the models, the licensee should
read this license and accept the terms.
The licensee may not sell, loan, rent, lease, or license the
models, in whole, in part, or in modified form, to anyone outside the licensee's company. The licensee may modify these
models to suit his specific application.
These models are 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.” In no event will
Intersil be liable for special, collateral, incidental, or consequential damages in connection with or arising out of the use
of these models. Intersil reserves the right to make changes
to the products and the models without prior notice.
All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems.
Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality
Intersil products are sold by description only. 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 data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and
reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result
from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.
For information regarding Intersil Corporation and its products, see www.intersil.com
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