SPICE MODEL of LM7924 SIMetrix in SPICE PARK. English Version is http://www.spicepark.net. Japanese Version is http://www.spicepark.com by Bee Technologies.

1. Device Modeling Report
COMPONENTS: VOLTAGE REGULATOR
PART NUMBER: LM7924
MANUFACTURER: FAIRCHILD SEMICONDUCTOR
Panasonic
Bee Technologies Inc.
All Rights Reserved Copyright (c) Bee Technologies Inc. 2010
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2. CIRCUIT CONFIGURATION
U1
LM7924
IN OUT
GND
MODEL PARAMETER
Model
Model description
parameter
VREF Reference Voltage
N Emission Coefficient
BETA Tranconductance of JFET Transistor
VAF Early Voltage of Output Pass Transistor
CPZ Output Impedance Zero Capacitor
RB2 Base Resistance of Output Limit Voltage Source
ESC1 Coefficient of Current Limit Voltage Source
ESC2 Coefficient of Current Limit Voltage Source
EFB1 Coefficient of Foldback Current Voltage Source
EFB2 Coefficient of Foldback Current Voltage Source
EFB3 Coefficient of Foldback Current Voltage Source
EB Non-ideal Base-Collector Diode Saturation Current
All Rights Reserved Copyright (c) Bee Technologies Inc. 2010
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3. Input-Output Voltage Differential Characteristics
Simulation Result
0
-5
-10
OUTPUT / V
-15
-20
-25
-35 -30 -25 -20 -15 -10 -5 0
V1/V 5V/div
Evaluation Circuit
0 1A
V1 C1 C0 I1
2.2u 1u
GND OUTPUT
IN OUT
LM7924
U1
Comparison Table
Condition: IO = 1A, VI = -33V, CI = 2.2μF, CO = 1μF
Parameter Measurement Simulation %Error
VDROP (V) 2.000 2.043 2.15
All Rights Reserved Copyright (c) Bee Technologies Inc. 2010
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4. Ripple Rejection (RR) Characteristics
Simulation Result
-28
U1-IN / V
-32
-36
-40
-23.992
OUTPUT / V
-23.996
-24
-24.004
-24.008
0 5 10 15 20 25 30 35 40
Time/mSecs 5mSecs/div
Evaluation Circuit
-33
V2
C1 C0
2.2u 1u 45
R1
AC 1 0 Sine(0 5 120 0 0)
V1
GND OUTPUT
IN OUT
LM7924
U1
Comparison Table
Condition: IO = 500mA, VI = 33V, CI = 2.2μF, CO = 1μF, f = 120Hz, ΔVI = 10V
Parameter Measurement Simulation %Error
RR(dB) 60.000 59.373 -1.04
All Rights Reserved Copyright (c) Bee Technologies Inc. 2010
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5. Output Characteristics
Simulation Result
0
-5
-10
:OUT / V
-15
-20
-25
-30
-2.2 -2 -1.8 -1.6 -1.4 -1.2 -1 -0.8 -0.6 -0.4 -0.2 -0
IRL/A 200mA/div
Evaluation Circuit
5 100Meg V=V(2,0)+V(3,0)
RL R2 B2
-33 2 3
V1 C1 C2 5 Pulse(10 50m 50m 500m 50n 50n 600m)
1 100Meg 100Meg 5 Pulse(0 100 0 50n 50n 50m 600m)
0.33uF 0.1uF V2
V=V(1,0)*(V(4, 0)-1) R3 R4 V3
B1
GND 4
IN IN OUT OUT
LM7924
U1
Comparison Table
Condition: IO = 250mA to 750mA, VI = 33V, CI = 2.2μF, CO = 1μF
Parameter Measurement Simulation %Error
VO(V) -24.000 -24.002 0.01
IPEAK(A) 2.200 2.183 -0.77
All Rights Reserved Copyright (c) Bee Technologies Inc. 2010
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