Datasheet RV4145A Datasheet (Fairchild Semiconductor)

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RV4145A

Low Power Ground Fault Interrupter

Features

• No potentiomenter required

• Direct interface to SCR

• Supply voltage derived from AC line – 26V shunt

• Adjustable sensitivity

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.

• Grounded neutral fault detection

• Meets U.L. 943 standards

• 450µA quiescent current

• Ideal for 120V or 220V systems

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

V

FB

+Input

V

REF

(+13V)

Ground

RV4145A

R1

10K

R2

10K

6.5V

4.7K

R3

6.5V

6.5V

6.5V

65-4145A-01

Op Amp Output

+V

S

(+26V)

SCR Trigger

REV. 1.0.3 3/6/02

PRODUCT SPECIFICATION RV4145A

Pin Assignments

8-Pin PDIP

V

FB

+Input

V

REF

GND

8-Pin SOIC

8

1

7

2

6

3

5

4

NC

Op Amp Output

+V

S

SCR Trigger

+Input

V

GND

NC

REF

8-Pin MSOP

8

1

7

2

6

3

5

4

V

FB

Op Amp Output

+V

S

SCR Trigger

65-4145A-02

Absolute Maximum Ratings

(beyond which the device may be damaged)

Parameter Min Typ Max Units

Supply Current 18 mA

Internal Power Dissipation 500 mW

Storage Temperature Range -65 +150 °C

Operating Temperature Range -35 +85 °C

Junction Temperature 125°C

Lead Soldering Temperature 60 Sec, DIP 300 °C

T

< 50°C SOIC 300 mW

P

D

A

For T

> 50°C Derate at SOIC 4 mW/°C

A

Notes:

1. Functional operation under any of these conditions is NOT implied. Performance and reliability are guaranteed only if
Operating Conditions are not exceeded.

1

10 Sec, SOIC, MSOP 260 °C

PDIP 450 mW

MSOP 350 mW

PDIP 6 mW/°C

MSOP 4.7 mW/°C

Operating Conditions

Parameter Min Typ Max Units

θ

JA

2

Thermal resistance SOIC 240 °C/W

PDIP 160 °C/W

MSOP 206 °C/W

REV. 1.0.3 3/6/02

≤

RV4145A PRODUCT SPECIFICATION

Electrical Characteristics

Parameters Test Conditions Min Typ Max Units

Detector Reference Voltage Pin 7 to Pin 3 6.8 7.2 8.1 ±V

Shunt Regulator

Zener Voltage (+V

Reference Voltage (V

Quiescent Current (I

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 3 650 µA

–Output Source Current Pin 7 to Pin 3 1.0 mA

Gain Bandwidth Product F = 50KHz 1.0 1.8 MHz

Resistors I

R1 Pin 1 to Pin 3 10 k Ω

R2 Pin 2 to Pin 3 10 k Ω

R3 Pin 5 to Pin 4 3.5 4.7 5.9 k Ω

SCR Trigger Voltage Pin 5 to Pin 4

Detector On 1.5 2.8 V

Detector Off 0 1 10 mV

) Pin 6 to Pin 4 25 26 29.2 V

S

) Pin 3 to Pin 4 12.5 13 14.6 V

REF

)+V

S

(I

= 1.5mA and T

S

= 24V 450 750 µA

S

= 0mA

S

= +25°C)

A

Electrical Characteristics

Parameters Test Conditions Min Typ Max Units

Detector Reference Voltage Pin 7 to Pin 3 6.5 7.2 8.3 ±V

Shunt Regulator

Zener Voltage (+V

Reference Voltage (V

Quiescent Current (I

Operational Amplifier

Offset Voltage Pin 2 to Pin 3 -5.0 0.5 +5.0 mV

+Output Voltage Swing Pin 7 to Pin 3 6.5 7.2 8.3 V

–Output Voltage Swing Pin 7 to Pin 3 -9 -11.2 -14 V

Gain Bandwidth Product F = 50KHz 1.8 MHz

Resistors I

R1 Pin 1 to Pin 3 10 k Ω

R2 Pin 2 to Pin 3 10 k Ω

R3 Pin 5 to Pin 4 3.5 4.7 5.9 k Ω

SCR Trigger Voltage Pin 5 to Pin 4

Detector On 1.3 2.8 V

Detector Off 0 3 50 mV

) Pin 6 to Pin 4 24 26 30 V

S

) Pin 3 to Pin 4 12 13 15 V

REF

)+V

S

(I

= 1.5mA and -35°C ≤ T

S

= 23V 500 µA

S

= 0mA

S

A

+85°C)

REV. 1.0.3 3/6/02

3

×

PRODUCT SPECIFICATION RV4145A

Principles of Operation

The 26V shunt regulator voltage generated by the string of
zener diodes is divided into three reference voltages: 3/4 V
1/2 V

, and 1/4 V

S

ence 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:

V

= R

7

Where V
R

SENSE

pin 7 to pin 1, I
N is the turns ratio of the transformer. When V
or minus 7.2V relative to pin 3 the SCR Trigger output will
go high and fire the external SCR.

The formula for V
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.

is the RMS voltage at pin 7 relative to pin 3,

7

is the value of the feedback resistor connected from

Shunt Regulator

R

limits the current into the shunt regulator; 220V

LINE

applications will require substituting a 47k Ω 2W resistor. In
addition to supplying power to the IC, the shunt regulator
creates internal reference voltages (see above).

Operational Amplifier

R
sensitivity to normal faults. To adjust R
procedure: apply the desired fault current (a difference in
current of 5mA is the UL 943 standard). Adjust R
upward until the SCR activates. A fixed resistor can be used
for R
will meet UL’s 943 4-6mA specification window.

is a feedback resistor that sets gain and therefore

SENSE

SENSE

. V

S

SENSE

SENSE

, since the resultant ±15% variation in sensitivity

is at 1/2VS and is used as a refer-

REF

I

is approximate because it does not

7

/N

SENSE

is the fault current in amps RMS and

exceeds plus

7

, follow this

SENSE

SENSE

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

,

S

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 2 Ω 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. C
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.

is a

F

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,
[phone], and Magnetics, 900 E. Butler Road,
P.O. Box 391, Butler, PA 16003, [phone] 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.

4

REV. 1.0.3 3/6/02

RV4145A PRODUCT SPECIFICATION

Press

R

TEST

To Test

Line

Mov

Sense Transformer

1000:1

C1

10µF

15K

Hot

Neutral

V

V

GND

FB

REF

R

SENSE

1M *

RV4145

Op Amp Output

(+13V)

+V

SCR Trigger

Ground Neutral

Transformer

200:1

C3

0.01 µF

C4

S

R

LINE

24K

C

F

2.2 µF

0.03 µF

Q1 ON Semi

MCR100-6

C2

0.01µF

Latching
Contacts

K1

Load

Solenoid

DB1

1N4004 (4)

* Value depends on transformer characteristics.

Figure 1. GFI Application Circuit (Three-Wire Outlet)

65-4145A-03

REV. 1.0.3 3/6/02

5

PRODUCT SPECIFICATION RV4145A

Press

R

SENSE

1M *

To Test

Latching

Contacts

K1

Load

Line

Mov

Sense Transformer

1000:1

R

TEST

15K

Hot

Neutral

C1

10µF

V

V

GND

FB

REF

RV4145

Op Amp Output

(+13V)

SCR Trigger

+V

Solenoid

S

R

LINE

24K

Q1 Tag

X0103DA

DB1

1N4004 (4)

C2

0.01µF

65-4145A-04

* Value depends on transformer characteristics.

Figure 2. GFI Application Circuit (Two-Wire Outlet)

C

F

2.2 µF

6

REV. 1.0.3 3/6/02

RV4145A PRODUCT SPECIFICATION

Schematic Diagram

(6)

S

+V (+26V)

Q20

6.5V

R7

250K

Q13

Q11

Q19

Q12

6.5V

(3)

Q15

Q23

REF

V

(+13V)

Q18

R14

6.5V

1.3K

R13

30K

R6

Q17

450

6.5V

Q16

Q14

R12

Z1

7.2K

5.6V

Q10

R9

Q9

R3

39K

4.7K

(4)

Ground

Substrate

(5)

(7)

65-4145A-05

SCR Trigger

Op Amp Output

R2

R10

6K

10K

R1

10K

Q3

Q22

Q21

(1)

(+)

(-)

Q1

Q2

C1

4 pF

Q8

Q7

R5

50K

Q5

R4

Q6

C2

FB

(2)

V

+Input

50K

Q4

10 pF

REV. 1.0.3 3/6/02

7

PRODUCT SPECIFICATION RV4145A

Mechanical Dimensions

8-Lead Plastic DIP Package

Symbol

A — .210 — 5.33

A1 .015 — .38 —

A2 .115 .195 2.93 4.95
B .014 .36

B1 .045 .070 1.14 1.78
C .008 .015 .20 .38

D .348 .430 8.84 10.92

D1
E
E1
e

eB
L

N

E1

Inches

Min. Max. Min. Max.

.022 .56

.005 — .13 —
.300 .325 7.62 8.26
.240 .280 6.10 7.11

.100 BSC 2.54 BSC

— .430 — 10.92

.115 .160 2.92 4.06

8° 8° 5

D

4

1

Millimeters

Notes

4

2

2

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.

5

D1

A

A1

B1

8

e

A2

L

B

E

C

eB

8

REV. 1.0.3 3/6/02

RV4145A PRODUCT SPECIFICATION

Mechanical Dimensions

(continued)

8-Lead SOIC Package

Symbol

A .053 .069 1.35 1.75

A1 .004 .010 0.10 0.25

B .013 0.33

C .008 .010 0.20 0.25
D .189 .197 4.80 5.00

E .150 .158 3.81 4.01

e

H

h

L .016 .050 0.40 1.27

N8 8

α

ccc .004 0.10——

85

Inches

Min. Max. Min. Max.

.020 0.51

.050 BSC 1.27 BSC

.228 .244 5.79 6.20

.010 .020 0.25 0.50

0° 8° 0° 8°

EH

Millimeters

Notes

5
2

2

3
6

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.

"C" dimension does not include solder finish thickness.

6.

Symbol "N" is the maximum number of terminals.

14

D

A

e

B

A1

SEATING
PLANE

– C –

LEAD COPLANARITY

ccc C

h x 45°

C

α

L

REV. 1.0.3 3/6/02

9

PRODUCT SPECIFICATION RV4145A

Mechanical Dimensions

8-Lead MSOP Package

Package MA08D

0.118 - 0.004
[3 ± 0.1]

–A–

85

SYMM

C

0.193 ± 0.004
[4.9 ± 0.1]

PIN 1

IDENT

14

0.030 - 0.037
[0.78 - 0.94]

–C–

0.002 [0.05]

0.002 - 0.006
[0.06 - 0.15]

TYP

C

0.012 ± 0.002
[0.3 ± 0.05]

0.002 [0.05]

TYP

MSA

0.118 ± 0.004

(0.0256)

[0.65]

(0.033)

[0.84]

SB

[3 ± 0.1]

–B–

TYP

(0.040)

TYP

[1.02]

(0.016)

TYP

[0.41]

LAND PATTERN RECOMMENDATION

0.005
TYP

R

[0.13]

0.005
TYP

R

[0.13]

0.021 ± 0.005

0.0375
[0.953]

0.007 ± 0.002
[0.18 ± 0.05]

[0.53 ± 0.12]

TYP

(0.189)

[4.8]

(0.0256)

TYP

[0.65]

0°–6° TYP

SEATING PLANE

GAGE
PLANE

(0.010)

[0.23]

8-Lead Molded Small Outline Package (MSOP), JEDEC MO-187, 3.0mm Wide

Package Number MA08

D

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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3/6/02 0.0m 001

 2002 Fairchild Semiconductor Corporation

Stock#DS2004145A