FAN4147SX_技术文档

March 2013

FAN4147

Ground Fault Interrupter

Features

Description

The FAN4147 is a low-power Ground Fault Interrupter

(GFI) controller for detecting hazardous current paths to

ground and ground-to-neutral faults. The FAN4147

application circuit opens the load contacts before a

harmful shock occurs.

.

For GFCI and RCD Applications

Precision Sense Amplifier and Bandgap Reference

Built-in AC Rectifier

Built-in Noise Filter

Internally, the FAN4147 contains a diode rectifier,

precision bandgap 12V shunt regulator, precision low-

V_OSoffset-sense amplifier, time delay noise filter,

window-detection comparators, and an SCR driver. With

Low-Voltage SCR Disable

Direct DC Coupled to Sense Coil

SCR Gate Driver

a

minimum number of external components, the

FAN4147 detects and protects against a hot-wire-to-

ground fault and a neutral-line-to-neutral-load short. The

minimal components and the small SuperSOT™

package allow for a small-form-factor, low-cost solution.

Adjustable Sensitivity

400A Quiescent Current

Minimum External Components

Meets UL 943 Requirements

Ideal for 120V or 220V Systems

Space Saving SuperSOT™ 6-Pin Package

The FAN4147 circuitry has a built-in rectifier and shunt

regulator that operates with a low quiescent current.

This allows for a high-value, low-wattage-series supply

resistor. The internal temperature-compensated shunt

regulator, sense amplifier, and bias circuitry provide for

precision ground-fault detection. The low-V_OSoffset-

sense amplifier allows direct coupling of the sense coil

to the amplifier’s feedback signal. This eliminates the

large 50/60Hz AC-coupling capacitor. The internal delay

filter rejects high-frequency noise spikes common with

inductive loads. This decreases false nuisance tripping.

The internal SCR driver is temperature compensated

and designed to satisfy the current requirements for a

wide selection of external SCRs.

Applications

.

GFCI Output Receptacles

GFCI Circuit Breakers

Portable GFCI Cords

The minimum number of external components and the

6-pin SuperSOT™ package enable a low-cost, compact

design and layout.

Ordering Information

Operating

Temperature Range

Part Number

Package

Packing Method

FAN4147SX

-35°C to +85°C

6-Lead SUPERSOT6, JEDEC M0-193, 1.6mm

Tape and Reel

www.fairchildsemi.com

FAN4147 • Rev. 1.0.1

Block Diagram

AMPOUT

VS

C₁

I₁

VFB

SCR

VREF

A₁

Delay

T₁

SCR

Driver

Q₁

R₁

VTH

C₂

VS

VREF

VTH

Neutral

Line

VREF

Rectifier

and Bias

Figure 1. Block Diagram

Typical Application

TEST

R_TEST

Neutral Coil 1:200

Sense Coil 1:1000

Load Hot

Line Hot

Load Neutral

Line Neutral

C2

C3

MOV

R_IN

Q1

R_SET

AmpOut

VFB

SCR

C1

C4

Neutral

Line

VREF

R1

Figure 2. Typical Application⁽¹⁾

Typical Values

(2)

C1: 22nF

C2: 10nF

C3=1nF

R1: 91K

R_SET: 511K

R_IN: 470Ω

R_TEST: 15KΩ

C4=10nF

Notes:

1. Contact Fairchild for best application practices for nuisance tripping rejection.

2. Exact values depend on sense coil characteristics and application.

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FAN4147 • Rev. 1.0.1

2

Pin Configuration

6

5

4

1

2

3

PI 1

AmpOut

VF

SC

Neutral

Line

VRE

Figure 3. Pin Configuration

Pin Definitions

Pin #

Name

Description

1

2

3

4

5

6

SCR

Neutral

Line

Gate drive for external SCR

Supply input for FAN4147 circuitry

VREF

VFB

Non-inverting input for current-sense amplifier

Inverting input for current-sense amplifier

AmpOut An external resistor connected to the VFB pin sets the I_faultsensitivity threshold

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FAN4147 • Rev. 1.0.1

3

Absolute Maximum Ratings

Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be

operable above the recommended operating conditions and stressing the parts to these levels is not recommended.

In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability.

The absolute maximum ratings are stress ratings only.

Symbol

Parameter

Continuous Supply Current, Line to Neutral

Continuous Supply Voltage, Line to Neutral

Continuous Voltage to Neutral, All Other Pins

Storage Temperature Range

Min.

Max.

15

Unit

mA

V

I_CC

-1.2

-0.8

-65

16

V_CC

15

V

T_STG

+150

2.5

1.0

0.2

°C

Human Body Model, JESD22-A114

Electrostatic Discharge

Protection Level

ESD

Charged Device Model, JESD22-C101

Machine Model, JESD22-A115

kV

Recommended Operating Conditions

The Recommended Operating Conditions define conditions for actual device operation. Recommended operating

conditions are specified to ensure optimal performance to the datasheet specifications. Fairchild does not recommend

exceeding them or designing to Absolute Maximum Ratings. (Unless otherwise specified, refer to figure 2.)

Symbol

Parameter

Conditions

Min. Typ. Max. Unit

DC Electrical Parameters (T_A=25°C, I_shunt=1mA)

Line to Neutral

12.2

-0.9

12.7

-0.7

13.2

V

Power Supply Shunt Regulator

Voltage

V_REG

Line to Neutral I_shunt=-2mA

I_Q

V_REF

V_TH

V_OS

I_OS

Quiescent Current

Reference Voltage

Trip Threshold

Line to Neutral=10V

VREF to Neutral

AmpOut to VREF

Gain=1000

350

5.8

400

6.0

3.5

0

450

6.2

3.6

450

50

µA

V

3.4

V

Amplifier Offset

-450

-50

µV

nA

dB

MHz

Amplifier Input Offset⁽³⁾

Amplifier DC Gain⁽³⁾

Amplifier Gain Bandwidth⁽³⁾

Design Value

0

G

Design Value

100

1.5

f_GBW

Design Value

V_SW+

V_SW-

Amplifier Positive Voltage Swing

Amplifier Negative Voltage Swing

4.0

V

AmpOut to VREF, I_FAULT=10A

VREF to AmpOut, I_FAULT=-10A

AmpOut=V_REF+ 3V,

V_FB=V_REF+ 100mV

I_SINK

Amplifier Current Sink

400

µA

AmpOut=V_REF– 3V,

V_FB=V_REF- 100mV

I_SRL

t_d

Amplifier Current Source

Delay Filter

400

0.7

µA

ms

K

-

1.0

0.5

1.3

1.0

Delay from C₁trip to SCR L >H

SCR to Neutral=250mV,

AmpOut=V_REF

R_OUT

SCR Output Resistance

SCR to Neutral AmpOut=V_REF

1

10

mV

V

V_OUT

SCR Output Voltage

SCR Output Current

SCR to Neutral AmpOut=V_REF+4V 2.5

SCR to Neutral=1V,

350

I_OUT

Note:

500

µA

AmpOut=V_REF+ 4V

3. Guaranteed by design; not tested in production.

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FAN4147 • Rev. 1.0.1

4

Functional Description

(Refer to Figure 1 and Figure 2.)

oscillate. When the peak oscillation voltage exceeds the

SCR trigger threshold, the internal delay timer is

enabled. Since the amplifier’s output signal is crossing

the window comparator’s trip threshold typically at 6KHz,

the delay timer alternates between detection of a

fault/no fault. The ratio of the fault/no-fault detection time

interval determines if the SCR driver is enabled.

The FAN4147 is a GFCI controller for AC ground-fault

circuit interrupters. The internal rectifier circuit is

supplied from the AC line during the positive half cycle

of the AC line voltage. The internal 12V shunt regulator

uses a precision temperature-compensated bandgap

reference. The combination of precision reference

circuitry and precision sense amplifier provides for an

accurate ground-fault tolerance. This allows for selection

of external components with wider, lower-cost,

parameter variations. Due to the low quiescent current,

a high-value external series resistor (R1) can be used,

which reduces the maximum power wattage required.

The 12V shunt regulator generates the reference

voltage for the sense amplifier’s (A₁) non-inverting input

(AC ground reference) and supplies the bias for the

delay timer (T₁), comparators (C₁& C₂), and SCR driver.

The sensitivity of the grounded neutral detection is

changed by the neutral coil turns and C2, C3 values.

R_SETResistor Calculation

The AmpOut signal must exceed the window

comparator’s V_THthreshold voltage for longer than the

delay timer. Therefore:

The secondary winding of the sense transformer is

connected to pin 4 (VREF) and to a resistor R_INdirectly

DC connected to the inverting input of the sense

(1)

(2)

V_TH=I_FAULTx 1.41 x R_SETx C_OS(2 x (t/2P)) / N

R_SET=(V_THx N) / (1.41 x I_FAULTx C_OS( x t/P))

amplifier at pin 5 (VFB). The feedback resistor (R_SET

)

where:

converts the sense transformer’s secondary current to a

voltage at pin 6 (AmpOut). This voltage is compared to

the internal window comparator (C₁& C₂) and, when the

AmpOut voltage exceeds the +/-V_THthreshold voltage,

the window comparator triggers the internal delay timer.

The output of the window comparator must stay HIGH

for the duration of the t₁timer. If the window

comparator’s output goes LOW, the internal delay timer

starts a reset cycle. If the window comparator’s output is

still HIGH at the end of the t₁pulse, the SCR driver

enables the current source I₁and disables Q₁. The

current source I₁then enables the external SCR, which

energizes the solenoid, opens the contact switches to

the load, and removes the hazardous ground fault. The

window comparator allows for detection of a positive or

negative I_FAULTsignal independent from the phase of the

line voltage.

V_TH= 3.5V ;

I_FAULT= 5mA (UL943) ;

t

= 1ms (timer delay);

P

= Period of the AC Line (1/60Hz);

= Ratio of secondary to primary turns (1000:1);

N

505K511Kstandard 1% value^

R_SET

=

Note:

4. In practice, the transformer is non-ideal, so R_SET

may need to be adjusted by up to 30% to obtain the

desired I_faulttrip threshold.

V_OSTrip Threshold Error Calculation

The sense transformer typically has a toroidal core

made of laminated steel rings or solid ferrite material.

The secondary of the transformer is typically 800 to

1500 turns of #40 wire wound through the toroid. The

primary is typically one to two turns made by passing the

AC hot and neutral wires through the center of the

toroid. When a ground fault exists, a difference exists

between the current flowing in hot and neutral wires.

The primary difference current, divided by the primary-

to-secondary turns ratio, is the current that flows through

the secondary wire of the transformer.

Since the sense coil is DC connected to the feedback of

the sense amplifier, the V_OSoffset introduces an I_fault

threshold error. This error can be calculated as:

%Error=

100 x (V_OSx R_SET) / (R_IN+ RL_DC+ RL_AC) / V_TH

where:

(3)

V_OS

=

+/-450V (worse case);

+/-150V (typical);

511K

R_SET

R_IN

A grounded neutral condition occurs when the neutral-

line is grounded at the neutral-load side.

470 (typical value);

RL_DC

75 (sense coil secondary DC resistance);

Depending on the resistance of the grounded neutral

connection, this condition causes the sense coil to

detect a lower ground fault current. The detection of a

ground-to-load-neutral fault relies on the principle of

positive feedback. When this occurs, the sense and

neutral coils are mutually coupled, which produces a

positive feedback path around the sense amplifier. This

positive feedback causes the sense amplifier to

1.5K (AC_(jL)impedance of sense coil)

RL_AC

V_TH

=

(L= 4H, f= 60Hz);

= 3.5V;

%Error = +/- 3.2% (worst case); +/-1.1% (typical).

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FAN4147 • Rev. 1.0.1

5

Typical Performance Characteristics

Unless otherwise specified, results are T_A=25°C and according to Figure 2 with solenoid disconnected.

Line (pin 3) is clamped to 12.7V

during the positive V_AChalf cycle

Ch1: Line (Pin 3) 10V/Div

Ch2: AmpOut (Pin 6) 10V/Div

Ch3: VREF (Pin 4) 10V/Div

Ch4: V_ACInput 200V/Div

Figure 4. Typical Waveforms with No Ground Fault

Detection of I_Faultsignal

I_Fault= (V_Ampout– V_REF)•N/R_SET

Ch1: Line (Pin 3) 10V/Div

Ch2: AmpOut (Pin 6) 5V/Div

Ch3: SCR (Pin 1) 1V/Div

Ch4: I_Fault10mA/Div

Figure 5. Typical Waveforms with 4mA Ground Fault

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FAN4147 • Rev. 1.0.1

6

Typical Performance Characteristics

Unless otherwise specified, results are T_A=25°C and according to Figure 2 with solenoid disconnected.

SCR Output Triggered

Ch1: Line (Pin 3) 10V/Div

Ch2: AmpOut (Pin 6) 5V/Div

Ch3: SCR (Pin 1) 1V/Div

Ch4: I_Fault10mA/Div

Figure 6. Typical Waveforms with 5mA Ground Fault

SCR Output Triggered

Ch1: Line (Pin 3) 10V/Div

Ch2: AmpOut (Pin 6) 5V/Div

Ch3: SCR (Pin 1) 1V/Div

Ch4: I_Fault10mA/Div

Figure 7. Typical Waveforms with 5mA Ground Fault (Line Polarity Reversal)

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FAN4147 • Rev. 1.0.1

7

Typical Performance Characteristics

Unless otherwise specified, results are T_A=25°C and according to Figure 2 with solenoid disconnected.

Sense amplifier oscillates with 2Ω

grounded neutral fault

Ch1: Line (Pin 3) 10V/Div

Ch2: AmpOut (Pin 6) 5V/Div

Ch3: SCR (Pin 1) 1V/Div

Figure 8. Typical Waveforms for Grounded Neutral Detection

~6.9KHz Sense Amplifier

Oscillation

Ch2: AmpOut (Pin 6) 2V/Div

Figure 9. Typical Waveform for Grounded Neutral Detection

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FAN4147 • Rev. 1.0.1

8

Physical Dimensions

Figure 10. 6-Lead SUPERSOT™

Package drawings are provided as a service to customers considering Fairchild components. Drawings may change in any manner

without notice. Please note the revision and/or date on the drawing and contact a Fairchild Semiconductor representative to verify or

obtain the most recent revision. Package specifications do not expand the terms of Fairchild’s worldwide terms and conditions, specifically the

warranty therein, which covers Fairchild products.

Always visit Fairchild Semiconductor’s online packaging area for the most recent package drawings:

http://www.fairchildsemi.com/packaging/.

www.fairchildsemi.com

FAN4147 • Rev. 1.0.1

9

www.fairchildsemi.com

FAN4147 • Rev. 1.0.1

10


型号：	FAN4147SX
厂家：	FAIRCHILD SEMICONDUCTOR
描述：	Power Supply Support Circuit, Adjustable, 1 Channel, PDSO6, 1.60 MM, MO-193AA, SOT-6 光电二极管
文件：	总10页 (文件大小：527K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

FAN4147SX [FAIRCHILD]

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