FAIRCHILD RV4145A

www.fairchildsemi.com
RV4145A
Low Power Ground Fault Interrupter
Features
•
•
•
•
No potentiomenter required
Direct interface to SCR
Supply voltage derived from AC line – 26V shunt
Adjustable sensitivity
•
•
•
•
Grounded neutral fault detection
Meets U.L. 943 standards
450µA quiescent current
Ideal for 120V or 220V systems
Description
The RV4145A is a low power controller for AC outlet
ground fault interrupters. These devices detect hazardous
grounding conditions, such as equipment (connected to
opposite phases of the AC line) in contact with a pool of
water and open circuits the line before a harmful or lethal
shock occurs.
Contained internally are a 26V zener shunt regulator, an op
amp, and an SCR driver. WIth the addition of two sense
transformers, a bridge rectifier, an SCR, a relay, and a few
additional components, the RV4145A will detect and protect
against both hot wire to ground and neutral wire to ground
faults. The simple layout and conventional design ensure
ease of application and long-term reliability.
Block Diagram
RV4145A
VFB
+Input
R1
10K
Op Amp Output
R2
10K
VREF
(+13V)
6.5V
6.5V
6.5V
6.5V
Ground
+VS
(+26V)
SCR Trigger
R3
4.7K
65-4145A-01
REV. 1.0.3 3/6/02
PRODUCT SPECIFICATION
RV4145A
Pin Assignments
8-Pin PDIP
8-Pin SOIC
8-Pin MSOP
VFB
1
8
NC
+Input
2
7
Op Amp Output
NC
1
8
VFB
+Input
2
7
Op Amp Output
VREF
3
6
GND
4
5
+VS
VREF
3
6
+VS
SCR Trigger
GND
4
5
SCR Trigger
65-4145A-02
Absolute Maximum Ratings
(beyond which the device may be damaged)1
Parameter
Min
Typ
Supply Current
Internal Power Dissipation
Max
Units
18
mA
500
mW
Storage Temperature Range
-65
+150
°C
Operating Temperature Range
-35
+85
°C
Junction Temperature
Lead Soldering Temperature
PD TA < 50°C
For TA > 50°C Derate at
125°C
60 Sec, DIP
300
°C
10 Sec, SOIC, MSOP
260
°C
SOIC
300
mW
PDIP
450
mW
MSOP
350
mW
SOIC
PDIP
MSOP
4
mW/°C
6
mW/°C
4.7
mW/°C
Notes:
1. Functional operation under any of these conditions is NOT implied. Performance and reliability are guaranteed only if
Operating Conditions are not exceeded.
Operating Conditions
Parameter
θJA
2
Thermal resistance
Min
Typ
Max
Units
SOIC
240
°C/W
PDIP
160
°C/W
MSOP
206
°C/W
REV. 1.0.3 3/6/02
RV4145A
Electrical Characteristics
PRODUCT SPECIFICATION
(IS = 1.5mA and TA = +25°C)
Parameters
Test Conditions
Min
Typ
Max
Units
Detector Reference Voltage
Pin 7 to Pin 3
6.8
7.2
8.1
±V
Zener Voltage (+VS)
Pin 6 to Pin 4
25
26
29.2
V
Reference Voltage (VREF)
Pin 3 to Pin 4
12.5
13
14.6
V
Quiescent Current (IS)
+VS = 24V
450
750
µA
Shunt Regulator
Operational Amplifier
Offset Voltage
Pin 2 to Pin 3
-3.0
0.5
+3.0
mV
+Output Voltage Swing
Pin 7 to Pin 3
6.8
7.2
8.1
V
–Output Voltage Swing
Pin 7 to Pin 3
-9.5
-11.2
-13.5
V
+Output Source Current
Pin 7 to Pin 3
–Output Source Current
Pin 7 to Pin 3
Gain Bandwidth Product
F = 50KHz
Resistors
IS = 0mA
R1
650
µA
1.0
mA
1.8
MHz
Pin 1 to Pin 3
10
kΩ
R2
Pin 2 to Pin 3
10
kΩ
R3
Pin 5 to Pin 4
SCR Trigger Voltage
Pin 5 to Pin 4
1.0
4.7
Detector On
1.5
2.8
Detector Off
0
1
10
mV
Electrical Characteristics
5.9
kΩ
3.5
V
(IS = 1.5mA and -35°C ≤ TA ≤ +85°C)
Parameters
Test Conditions
Min
Typ
Max
Units
Detector Reference Voltage
Pin 7 to Pin 3
6.5
7.2
8.3
±V
Zener Voltage (+VS)
Pin 6 to Pin 4
24
26
30
V
Reference Voltage (VREF)
Pin 3 to Pin 4
12
13
15
V
Quiescent Current (IS)
+VS = 23V
Shunt Regulator
500
µA
Operational Amplifier
Offset Voltage
Pin 2 to Pin 3
-5.0
+Output Voltage Swing
Pin 7 to Pin 3
6.5
–Output Voltage Swing
Pin 7 to Pin 3
-9
Gain Bandwidth Product
F = 50KHz
Resistors
IS = 0mA
R1
Pin 1 to Pin 3
R2
Pin 2 to Pin 3
R3
Pin 5 to Pin 4
SCR Trigger Voltage
Pin 5 to Pin 4
0.5
+5.0
mV
7.2
8.3
V
-11.2
-14
V
1.8
MHz
10
kΩ
4.7
Detector On
1.3
2.8
Detector Off
0
3
REV. 1.0.3 3/6/02
kΩ
10
3.5
5.9
kΩ
V
50
mV
3
PRODUCT SPECIFICATION
Principles of Operation
The 26V shunt regulator voltage generated by the string of
zener diodes is divided into three reference voltages: 3/4 VS,
1/2 VS, and 1/4 VS. VREF is at 1/2VS and is used as a reference to create an artifical ground of +13V at the op amp noninverting input.
Figure 1 shows a three-wire 120V AC outlet GFI application
using an RV4145A. Fault signals from the sense transformer
are AC coupled into the input and are amplified according to
the following equation:
V7 = RSENSE × ISENSE/N
Where V7 is the RMS voltage at pin 7 relative to pin 3,
RSENSE is the value of the feedback resistor connected from
pin 7 to pin 1, ISENSE is the fault current in amps RMS and
N is the turns ratio of the transformer. When V7 exceeds plus
or minus 7.2V relative to pin 3 the SCR Trigger output will
go high and fire the external SCR.
The formula for V7 is approximate because it does not
include the sense transformer characteristics.
Grounded neutral fault detection is accomplished when a
short or fault closes a magnetic path between the sense transformer and the grounded neutral transformer. The resultant
AC coupling closes a positive feedback path around the op
amp, and therefore the op amp oscillates. When the peaks of
the oscillation voltage exceed the SCR trigger comparator
thresholds, the SCR output will go high.
Shunt Regulator
RLINE limits the current into the shunt regulator; 220V
applications will require substituting a 47kΩ 2W resistor. In
addition to supplying power to the IC, the shunt regulator
creates internal reference voltages (see above).
Operational Amplifier
RSENSE is a feedback resistor that sets gain and therefore
sensitivity to normal faults. To adjust RSENSE, follow this
procedure: apply the desired fault current (a difference in
current of 5mA is the UL 943 standard). Adjust RSENSE
upward until the SCR activates. A fixed resistor can be used
for RSENSE, since the resultant ±15% variation in sensitivity
will meet UL’s 943 4-6mA specification window.
4
RV4145A
The roll-off frequency is greater than the grounded neutral
fault oscillation frequency, in order to preserve loop gain for
oscillation (which is determined by the inductance of the
200:1 transformer and C4).
The senstivity to grounded neutral faults is adjusted by
changing the frequency of oscillation. Increasing the frequency reduces the sensitivity by reducing the loop gain of
the positive feedback circuit. As frequency increases, the
signal becomes attenuated and the loop gain decreases. With
the values shown the circuit will detect a grounded neutral
fault having resistance of 2Ω or less.
The input to the op amp are protected from overvoltage by
back-toback diodes.
SCR Driver
The SCR used must have a high dV/dt rating to ensure that
line noise (generated by noisy appliances such as a drill
motor) does not falsely trigger the SCR. Also, the SCR must
have a gate drive requirement of less than 200µA. CF is a
noise filter capacitor that prevents narrow pulses from firing
the SCR.
The relay solenoid used should have a 3ms or less response
time in order to meet the UL 943 timing requirement.
Sense Transformers and Cores
The sense and grounded neutral transformer cores are usually fabricated using high permeability laminated steel rings.
Their single turn primary is created by passing the line and
neutral wires through the center of its core. The secondary is
usually from 200 to 1500 turns.
Magnetic Metals Corporation, Camden, NJ 08101,
(609) 964-7842, and Magnetics, 900 E. Butler Road,
P.O. Box 391, Butler, PA 16003, (412) 282-8282 are full line
suppliers of ring cores and transformers designed specifically for GFI applications.
Two-Wire Application Circuit
Figure 2 shows the diagram of a 2-wire 120V AC outlet GFI
circuit using an RV4145A. This circuit is not designed to
detect grounded neutral faults. Thus, the grounded neutral
transformer and capacitors C3 and C4 of Figure 1 are not
used.
REV. 1.0.3 3/6/02
RV4145A
PRODUCT SPECIFICATION
Press
To Test
RTEST
15K
Mov
Ground Neutral
Transformer
Sense Transformer
1000:1
Line
Latching
Contacts
K1
200:1
Hot
Neutral
RSENSE
1M *
C1
10µF
Load
C3
0.01 µF
RV4145
VFB
Op Amp Output
VREF (+13V)
GND
Solenoid
C4
0.03 µF
+VS
SCR Trigger
DB1
1N4004 (4)
RLINE
24K
Q1 ON Semi
MCR100-6
CF
2.2 µF
C2
0.01µF
65-4145A-03
* Value depends on transformer characteristics.
Figure 1. GFI Application Circuit (Three-Wire Outlet)
REV. 1.0.3 3/6/02
5
PRODUCT SPECIFICATION
RV4145A
Press
To Test
RTEST
15K
Mov
Sense Transformer
1000:1
Line
Latching
Contacts
K1
Hot
Neutral
RSENSE
1M *
C1
10µF
Load
RV4145
VFB
Op Amp Output
VREF (+13V)
GND
Solenoid
+VS
SCR Trigger
DB1
1N4004 (4)
RLINE
24K
Q1 Tag
X0103DA
CF
2.2 µF
C2
0.01µF
65-4145A-04
* Value depends on transformer characteristics.
Figure 2. GFI Application Circuit (Two-Wire Outlet)
6
REV. 1.0.3 3/6/02
REV. 1.0.3 3/6/02
+Input
(2)
VFB
(1)
Q21
10 pF
C2
Q22
(-)
R1
10K
Q4
Q1
R4
50K
Q6
Q3
R10
6K
Q5
Q2
Q7
R5
50K
(+)
R2
10K
Q8
4 pF
C1
Q9
Q23
Q11
Q10
R6
450
R14
1.3K
Q12
Q14
(7)
Z1
5.6V
Q15
R3
4.7K
R13
30K
Op Amp Output
R9
39K
Q13
R7
250K
Q17
6.5V
(5)
Ground
(4)
VREF
(+13V)
(3)
+VS (+26V)
65-4145A-05
SCR Trigger
Substrate
R12
7.2K
Q16
Q18
6.5V
Q19
6.5V
Q20
6.5V
(6)
RV4145A
PRODUCT SPECIFICATION
Schematic Diagram
7
PRODUCT SPECIFICATION
RV4145A
Mechanical Dimensions
8-Lead Plastic DIP Package
Inches
Symbol
A
A1
A2
B
B1
C
D
D1
E
E1
e
eB
L
Millimeters
Min.
Max.
Min.
Max.
—
.015
.115
.014
.045
.008
.348
.005
.300
.240
.210
—
.195
.022
.070
.015
.430
—
.325
.280
—
.38
2.93
.36
1.14
.20
8.84
.13
7.62
6.10
5.33
—
4.95
.56
1.78
.38
10.92
—
8.26
7.11
.100 BSC
—
.430
.115
.160
2.54 BSC
—
10.92
2.92
4.06
8°
8°
N
Notes:
Notes
1. Dimensioning and tolerancing per ANSI Y14.5M-1982.
2. "D" and "E1" do not include mold flashing. Mold flash or protrusions
shall not exceed .010 inch (0.25mm).
3. Terminal numbers are for reference only.
4. "C" dimension does not include solder finish thickness.
5. Symbol "N" is the maximum number of terminals.
4
2
2
5
D
4
1
5
8
E1
D1
E
e
A2
A
A1
C
L
B1
8
B
eB
REV. 1.0.3 3/6/02
RV4145A
PRODUCT SPECIFICATION
Mechanical Dimensions (continued)
8-Lead SOIC Package
Inches
Symbol
Min.
A
A1
B
C
D
E
e
H
h
L
N
α
ccc
Millimeters
Max.
Min.
Max.
.053
.069
.004
.010
.013
.020
.008
.010
.189
.197
.150
.158
.050 BSC
1.35
1.75
0.10
0.25
0.33
0.51
0.20
0.25
4.80
5.00
3.81
4.01
1.27 BSC
.228
.010
.016
5.79
0.25
0.40
.244
.020
.050
8
6.20
0.50
1.27
8
0°
8°
0°
8°
—
.004
—
0.10
8
Notes:
Notes
1. Dimensioning and tolerancing per ANSI Y14.5M-1982.
2. "D" and "E" do not include mold flash. Mold flash or
protrusions shall not exceed .010 inch (0.25mm).
3. "L" is the length of terminal for soldering to a substrate.
4. Terminal numbers are shown for reference only.
5
2
2
5. "C" dimension does not include solder finish thickness.
6. Symbol "N" is the maximum number of terminals.
3
6
5
E
1
H
4
h x 45°
D
C
A1
A
SEATING
PLANE
e
B
REV. 1.0.3 3/6/02
–C–
LEAD COPLANARITY
α
L
ccc C
9
PRODUCT SPECIFICATION
RV4145A
Mechanical Dimensions
8-Lead MSOP Package
Package MA08D
0.118 - 0.004
[3 ± 0.1]
8
–A–
SYMM
C
5
(0.189)
[4.8]
0.118 ± 0.004
[3 ± 0.1]
0.193 ± 0.004
[4.9 ± 0.1]
–B–
(0.040)
TYP
[1.02]
PIN 1
IDENT
(0.016)
TYP
[0.41]
1
(0.0256)
TYP
[0.65]
4
LAND PATTERN RECOMMENDATION
(0.0256) TYP
[0.65]
R
0.030 - 0.037
[0.78 - 0.94]
0.005
TYP
[0.13]
GAGE
PLANE
0.005
R
TYP
[0.13]
(0.010)
[0.23]
–C–
0.002 [0.05]
C
0.002 - 0.006
TYP
[0.06 - 0.15]
0.012 ± 0.002
TYP
[0.3 ± 0.05]
0.002 [0.05]
M
0.021 ± 0.005
[0.53 ± 0.12]
(0.033)
[0.84]
A S
B S
0.0375
[0.953]
0°–6° TYP
SEATING PLANE
0.007 ± 0.002
TYP
[0.18 ± 0.05]
8-Lead Molded Small Outline Package (MSOP), JEDEC MO-187, 3.0mm Wide
Package Number MA08D
10
REV. 1.0.3 3/6/02
PRODUCT SPECIFICATION
RV4145A
Ordering Information
Part Number
Package
Operating Temperature Range
RV4145AN
8-Lead Plastic DIP
-35°C to +85°C
RV4145AM
8-Lead Plastic SOIC
-35°C to +85°C
RV4145AMU
8-Lead Plastic MSOP
-35°C to +85°C
DISCLAIMER
FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY
PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY
LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER
DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS.
LIFE SUPPORT POLICY
FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES
OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR
CORPORATION. As used herein:
1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the body,
or (b) support or sustain life, and (c) whose failure to
perform when properly used in accordance with
instructions for use provided in the labeling, can be
reasonably expected to result in a significant injury of the
user.
2. A critical component in any component of a life support
device or system whose failure to perform can be
reasonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.
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