RV4140A
PRODUCT SPECIFICATION
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Functional Description
(Refer to Block Diagram and Figure 1 )
The shunt regulator generated by a 6.5V zener diode is built into the internal bridge rectifier. It is divided to create an internal reference voltage of 2.9V connected to pin 3. The condary of the n transformer is AC coupled to the inverting input of the n amplifier at pin 2; the non-invert-ing input is referenced to pin 3. A current feedback loop around the n amplifier ensures a virtual ground will be prented to the condary of the n transformer. In this manner it acts as a current transformer instead of a voltage transformer. In this mode, the transformer’s characteristics are very predictable and circuit adjustments are not neces-sary in production.
The n transformer has a toroidal core made of laminated steel rings or solid ferrite material. The condary of the transformer is 500 to 1000 turns of #40 wire wound through the toroid. The primary’
s one turn 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 difference primary current, divided by the number of condary turns, flows through the condary wire of the transformer.The AC coupled transformer condary current then flows through the n amplifier’s feedback loop, creating a full wave rectified version of the condary fault current. This current pass through R SET at pin 1, generating a voltage equal to R SET times the peak fault current divided by the n transformer turns ratio. This voltage is compared with the reference voltage at pin 3.
If the voltage at pin 1 is greater than pin 3, a comparator will charge C2 through a 29 m A current source at pin 8. If the voltage at pin 1 exceeds pin 3 for longer than the delay time, a 400 m A current will pul between pins 7 and 6 which will trigger the gate of the SCR.
If the voltage at pin 1 exceeds pin 3 for less than the delay time, the SCR will not trigger.
The fault current at which the controller triggers the SCR is dependent on the value of R SET and the time delay determined by C2.
UL 943 requires the circuit interrupter trip when the ground fault exceeds 6 mA and not trip when the
fault current is less than 4 mA.
Supply Current Requirements
The RV4140A has a built-in diode bridge rectifier that provides power to the chip independent of the polarity of the AC line. This eliminates the external rectifier required for previous GFCI controllers.
R LlNE limits the shunt regulator current to 2 mA. The rec-ommended value is 47K to 91K for 110V systems and 91K to 150K for 220V systems. The recommended maximum peak line current through R LlNE is 7 mA.
DO NOT connect a filter capacitor between pins 5 and 6 in an attempt to filter the supply voltage at the RV4140A.
Proper operaton of the RV4140A requires the internal supply voltage to be unfiltered.
SCR Driver
The SCR must have a high dV/dt rating to ensure that line noi (generated by electrically noisy appliances) does not fally trigger the SCR. Also, the SCR must have a gate drive requirement less than 200 m A. C3 is a noi filter that
prevents high frequency line puls from triggering the SCR.The relay solenoid ud should have a 3 ms or less respon time to meet the UL 943 timing requirement.
Supplier of Sen Transformers and Cores
Magnetic Metals Corporation, Camden, NJ 08101,
(609) 964-7842, supplies a full line of ring cores and trans-formers designed specifically for GFCI and related applica-tions.手臂力量太弱怎么锻炼
Determining the Values of RSET and C2
Determine the ground fault trip current requirement. This will be typically 5 mA in North America (117 V AC) and 10 mA in the UK and Europe.
怎样清炖排骨Determine the minimum amount of time delay required to prevent nuisance tripping. This will typically be 1 to 2 ms.The value of C2 required to provide the desired delay time is:
C2 = 10 x T
where C2 is in nF, and T is the desired delay time in ms.
PRODUCT SPECIFICATION RV4140A
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RV4140A PRODUCT SPECIFICATION Pin Assignments
Absolute Maximum Ratings
Parameter Min.Typ.Max.Units Supply Current7mA Internal Power Dissipation500mW Storage Temperature Range-65+150°C Operating Temperature Range-35+80°C Lead Soldering Temperature60 Seconds, DIP+300°C
10 Seconds, SOIC+260°C
Thermal Characteristics
Parameter8 Lead Plastic SOIC 8 Lead Plastic DIP Maximum Junction Temperature+125°C+125°C
Maximum P D T A<50°C300 mW468 mW
Thermal Resistance, q JA240°C/W160°C/W雷锋精神的故事
For T A > 50°C Derate at 4.1 mW/°C 6.25 mW/°C
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PRODUCT SPECIFICATION RV4140A Electrical Characteristics
I LINE = 1.2mA and T A = +25°C, R SET = 290k W
北湖公园Parameters Test Conditions Min.Typ.Max.Units Shunt Regulator (Pins 5 to 4)
Regulated Voltage I2-3 = 11m A 6.87.27.6V Regulated Voltage I LINE = 700 m A, I2-3 = 9m A 6.87.27.6V Sen Amplifier (Pins 2 to 3)
Offt Voltage Design Value-3.00 3.0mV Gain Bandwidth Design Value 2.0MHz Input Bias Current Design Value30100nA SCR Trigger (Pins 7 to 6)
Output Resistance V5-6 = open, I2-3 = 0m A 4.0 4.7 5.4k W Output Voltage I2-3 = 9m A00.110mV Output Voltage I2-3 = 11m A 1.4 2.0 2.6V Output Current V7-6 = 0V, I2-3 = 11m A300420600m A Reference Voltage (Pins 3 to 4)
Reference Voltage I LINE = 700 m A 2.6 2.9 3.2V Delay Timer (Pins 8 to 4)
佳能c100Delay Time1C8-4 = 20nF— 2.0—ms Delay Current I2-3 = 11m A232935m A
Note:宝宝感冒药
1.Delay time is defined as starting when the instantaneous n current (I 2-3) exceeds
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2.9V/R SET and ending when the SCR
trigger voltage V7-6 goes high.
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RV4140A PRODUCT SPECIFICATION
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