<Earth Leakage Detector IC>

RT8H044K
Adopting a system that counts three waves in 1.5 cycle.

DESCRIPTION

OUT LINE DRAWING

Unit : mm

The RT8H044K is a semiconductor integrated circuitdesigned for high-speed type earth leakage breakers.
This IC includes leakage and abnormal voltage detecting
functions

FEATURES⚫ Switchable earth leakage detection mode ;counting three waves of 1.5 cycle.
⇔ counting two waves of a cycle.
⚫ Abnormal voltage detecting (neutral conductor openphase protection) function :・ Neutral conductor open phase protection atsingle phase three wire system.
•In case of no use this function, stop thisfunction and reduction of circuit current,possible.
⚫ High input sensitivity ; 7.5mV (DC)⚫ Low current dissipation ;・ In stand-by condition : 900uA typical(Vs = 9V, Ta = 25 ℃)
・ When SCR is ON : 620uA typical(Vs = 9V, Ta = 25 ℃)⚫ Adopt Pulse output（thyristor drive）⚫ supply voltage range ; 7V to 12V⚫ operating ambient temperature ; -20 to 105 ℃

MARKING

RT8H044KXXXPIN LAYOUT①②③④⑤⑥⑦GNDIREFVREF
ILKI
TRC1TRC2PSEL⑧⑨⑩⑪⑫⑬⑭SCRT
OFFC
TTDC
IBLI
PSAV
VCC
VS

APPLICATION
Earth leakage breaker

190123-1

<Earth Leakage Detector IC>

RT8H044K
Adopting a system that counts three waves in 1.5 cycle.

BLOCK DIAGRAMPIN FANCTION DESCRIPTION
Pin No.

Pin Name

Function

1234GND
IREF
VREF
ILKI

5TRC16TRC27PSEL

8SCRT

GroundingConnects to resistor
Input reference level pin.
Input pin of the leakage detection circuit.
Connects to capacitor for integrating output signals of the leakage input signal level
discriminator. (negative)
Connects to capacitor for integrating output signals of the leakage input signal level
discriminator. (positive)
Logic function switching pin used when detecting leakage.
When the pin is grounded, counting three waves of 1.5 cycle. (neg.→pos.→neg.)
When the pin is VCC, counting two waves of 1 cycle. (neg.→pos.)
Output pin for drive a SCR.

9OFFC

The pin connects to capacitor for time setting of this function.

10

TTDC

Connects to capacitor for time setting of the abnormal voltage detection circuit.

11IBLI

12PSAV

13VCC

Input pin of the abnormal voltage detection circuit.
Switching pin used when detecting leakage ON/OFF.
When the pin is grounded, enable detecting leakage.
When the pin is VCC, disable detecting leakage.
Output pin of internal constant-voltage circuit.

14VS

Power supply

190123-1

<Earth Leakage Detector IC>

RT8H044K
Adopting a system that counts three waves in 1.5 cycle.

ABSOLUTE MAXIMUM RATINGS (Ta = 25°C, unless otherwise noted)
SymbolParameter

Conditions

Ratings

UnitmAVVmAmAmAmWmW/℃℃℃

ISVS
VIL
IIL
IVREF
IIBLI
PdKθTstg

Source current
Supply voltage
Voltage between VREF and ILKI
Current between VREF and ILKI
VREF input voltage
IBLI input current
Power dissipation
Thermal derating
Storage temperature(keep dry)

415
-1.4～1.4
-5～5
10
4200
1.6
－40～125

Topr

Operating temperature(keep dry)

－20～105

Ta≧25℃

190123-1

<Earth Leakage Detector IC>

RT8H044K
Adopting a system that counts three waves in 1.5 cycle.

ELECTRICAL CHARACTERISTICS (Ta = 25℃, VS = 9Vunless otherwise noted)
LimitsSymbolParameter

Test conditions

IS0IS1
IS2
IS3
IS0'
IS1'
IS3'
VSmax
Vion
IIH
VO
VILKI
VRCL
EIOH
VTH
ETW1EIOH
VTH

Supply current : in stand-by
Supply current : in detecting earth leakage
Supply current : in detecting abnormal voltage
Supply current : in Immediately after SCR drive
Supply current : in stand-by
Supply current : in detecting earth leakage
Supply current : in Immediately after SCR drive
IS0 : Temperature dependency
Maximum current voltage
Earth leakage detection : DC input voltage
ILK1 pin input bias current
VREF pin output voltage
ILKI-VREF input clamp voltage
VREF-GND clamp voltage
TRC1 pin “H” output current precision
TRC1 threshold voltage
TW1 pulse width precision
TW1 variation with ambient temperature
TRC2 pin “H” output current precision
TRC2 threshold voltage

PSAV=VCCPSAV=VCCPSAV=VCCPSAV=VCCPSAV=GNDPSAV=GNDPSAV=GND
Ta=-20～85℃
IS=4mAvs. VREF
VIN=VREF

ETW2

TW2 pulse width precision

VT
VBLT
IIBLT
VIBLC
EIOH
VTH
ETW4
EIOH
VTHETW3VOL
IOHc
IOHn
IOHhVsoff

TW2 variation with ambient temperature

C=0.0047uF:TW2=1.0ms
1.1m
Ta=-20～85℃
60HzTotal leakage detecting AC voltage

IILKI=±3mA
IRCL=5mA
VO=0V:IOH=-10.4uA
C=0.01uF:TW1=2.1ms
Ta=-20～85℃
VO=0V:IOH=-10uA

Abnormal voltage detecting voltage
VBLT variation with supply voltage
VBLT variation with ambient temperature
IBLI pin input bias current
IBLI-GND clamp voltage
TTDC pin “H” output current precision

Ta=-20～85℃
VIN=VREF
IIN=1mA
VO=0V:IOH=-8uA

TTDC threshold voltage
Delay time pulse width precision
OFFC pin “H” output current precision

C=1.0uF:TW4=280ms
VO=0V:IOH=-10uA

OFFC threshold voltage
Reset timer pulse width precision
SCRT pin “L” output voltage
SCRT pin “H” output current
IOH holding supply voltage

C=0.33uF:TW3=52ms
IOL=200uA
Ta=-20℃
VO=0.8V Ta=25℃
Ta=85℃

Unit
Min

TypMax

630
670
630
430
570
590
430
-20-15-20-900
950
900
620
810
840
620
-0.12
14.3
±7.52
2.6
±1.3
5.02.3-0.06
2.31040
1080
1060
730
950
960
730
15.5
15201520-uA
uA
uA
uA
uA
uA
uA%/VV
mVnA
VVV%
V%%/℃%
V-15-

15%

5.2
2.1-20-30-20-30-200-100-70--0.06
6.5
2.3
0.01
0.06
120
7.9
2.4
2.30.1-280-230-160
3.0

7.8
2.5
300
2030
2030
0.2
4.5%/℃mVrms
V％/V％/℃
nA
V％
V％％
V％
VuA
uA
uA
V

190123-1

<Earth Leakage Detector IC>

RT8H044K
Adopting a system that counts three waves in 1.5 cycle.

I/O EQUIVALENT CIRCUIT
1pin：GND

2pin：IREF

3pin：VREF、4pin：ILKI

6 diodes5pin：TRC1

6pin：TRC2

7pin：PSEL

8pin：SCRT

190123-1

<Earth Leakage Detector IC>

RT8H044K
Adopting a system that counts three waves in 1.5 cycle.
9pin：OFFC

10pin：TTDC

11pin：IBLI

12pin：PSAV

7 diodes13pin：VCC、14pin：VS

9 diodes190123-1

<Earth Leakage Detector IC>

RT8H044K
Adopting a system that counts three waves in 1.5 cycle.

Timing chart
1. In detecting earth leakage(1) Counting three waves of 1.5 cycle. (PSEL=GND)
Vion(+)
ILKI-VREF

Vion(-)
TW1VTH

TRC1TW2VTH

TRC2VTHOFFC

TW3SCRT(2) Counting two waves of a cycle. (PSEL=VCC)
Vion(+)
ILKI-VREF

Vion(-)
TW1VTH

TRC1TW2VTH

TRC2VTH

OFFC

SCRT

TW3190123-1

<Earth Leakage Detector IC>

RT8H044K
Adopting a system that counts three waves in 1.5 cycle.

2. In detecting abnormal voltage.
VTH

IBLI

VTH

OFFC
VTH

TTDC
TW4SCRT

TW3190123-1

<Earth Leakage Detector IC>

RT8H044K
Adopting a system that counts three waves in 1.5 cycle.

Thermal derating curvePower consumption Pd [mW]

Thermal derating curve
2502001501005000255075100125150

Ambient temperature Ta (℃)

190123-1

<Earth Leakage Detector IC>

RT8H044K
Adopting a system that counts three waves in 1.5 cycle.

APPLICATION CIRCUIT EXAMPLE

190123-1

<Earth Leakage Detector IC>

RT8H044K
Adopting a system that counts three waves in 1.5 cycle.

PRECAUTIONS FOR APPLICATIONThe notes on using RT8H044K are shown below. The following precautions are only examples. Please carry out sufficientverification.

VS applied voltage(1) IS circuit current (clamp circuit characteristics of the equivalent circuit) is as shown in TYPICAL
CHARACTERISTICS figure.

Supply current IS (mA)

Temperature characteristic ; VS clamp voltage

Power-supply voltage VS (V)(2) Use of the IC by rectifying commercial power supplyRSVZa)b)

As Vz, be sure to use zener diode of 15V or less (not exceeding the absolute maximum rating of 12V).
At high temperatures, clamp voltage decreases and ls increases. Increase of ls will be restricted at RS, however.

(3) If normal DC power supply is used, use the IC at Vs=7to10V.

Resistor of IREF pin (R = 130kΩ)
Reference constant current source of the IC (for restraining fluctuations in supply voltage
characteristics and ambient temperature characteristics). Since this resistor determines thecharacteristics of each circuit, use of high-precision resistor (±2%) is recommended.
Although it is possible to suppress the circuit current by setting R = 150 kΩ etc.,
please perform sufficient verification.

190123-1

<Earth Leakage Detector IC>

RT8H044K
Adopting a system that counts three waves in 1.5 cycle.

Layout of printed circuit board
External noise (noise simulator etc.) may cause faulty operation of the IC. To improve the noiseimmunity, layout the printed circuit board so that the wiring of the external C and R is made asshort as possible. Special attention should be given to the wiring of the condensers connected to Vs,
Vcc and SCRT pins.

About SCRT output pin
Be careful that the voltage of SCRT output pin does not become lower than the GND level.
Change in sensitivity due to insulation deterioration
If the insulation of ZCT input pin from the high voltage part might deteriorate, improvement might be expectedby connecting a resistor of about R=100kΩ between VREF pin and GND. It should be noted that the circuitcurrent will increase at I 2.6V/R (approx.).

Clamp diode of IBLI input pin
As shown in the equivalent circuit, it is made up of series resistor and seven stages of forward diode.
(1) At high temperatures, the drop in diode VF may decrease the clamp voltage of the pin. If the voltage approaches thereference level of the comparator (2.3V) and current leaks occur, the overvoltage detection level may slightly
fluctuate. Form the detection circuit as the figure below. It is recommended that R1, R2 and VZ be set as shownbelow.
(2) During excessive input, as shown above, setting should be made so that the input pin voltage becomes 4.3V or lower(to prevent the saturated comparator circuit from operating). • VZ = 4.0V

R1R2・R1 + R2 > 200kΩ
VZ

R1×R2・R1+R2 < 7kΩ

190123-1

<Earth Leakage Detector IC>

RT8H044K
Adopting a system that counts three waves in 1.5 cycle.

Reset time in reset circuit.
This circuit is designed as a timer circuit of VL = 0.7V, VH = 2.3V and lo = 10µA. When SCR is ON, the power
supply route of the leakage detection and abnormal voltage detection circuits are shut off, VL does not drop to 0.7V
as shown below and therefore reset time may become shorter. Set the reset time somewhat longer in advance.

T=

CX(VH−VL)
0.33uF×（2.3−0.7）
=I
10uA

≒52ms

OFFC

SCRTNote. t : time shorter than setting value・ln the case of leakage detection : May become 10ms (50Hz) shorter・ln the case of abnormal voltage detection : May become 20ms (50Hz) shorter

190123-1

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Jan.2019