Cherry Semiconductor CS294GN8, CS294GDR8, CS294GD8 Datasheet

-

+

-

+

V

FB

Signal

Common

Filter

20kW

10kW

Bias

Gnd

Detect

4.7kW

50kW

Amp

OUT

+V

S

SCR
Trigger

-

+

The CS294 is an AC outlet ground
fault interrupter controller IC. The
IC detects the presence of haz­ardous grounding conditions and
open circuits the AC line before a
dangerous shock can occur.

The CS294 contains an operational
amplifier, an SCR driver and a 24V
zener shunt regulator. Two sense
coils, a bridge rectifier, a relay and

an SCR are required as external
components. The completed inter­rupter circuit can detect and protect
against both hot wire to ground
faults and neutral wire to ground
faults.

The CS294 is built on a 30V bipolar
process and is available in 8 lead
DIP packages.

Features

■ Supply Derived from

AC Supply Ñ 24V

■ Direct Interface to SCR

■ Adjustable Sensitivity

■ Grounded Neutral Fault

Detection

Package Options

CS294

Ground Fault Interrupter

CS294

Description

Block Diagram

V

FB

Filter

Signal Common

Gnd

Detect

Amp

OUT

+V

S

SCR Trigger

8 Lead PDIP & SO Narrow

1

Rev. 1/20/99

Cherry Semiconductor Corporation

2000 South County Trail, East Greenwich, RI 02818

Tel: [phone] Fax: [phone]

Email: [e-mail]

Web Site: www.cherry-semi.com

A Company

¨

1

V

FB

Error Amp Inverting Input 30V -0.3V N/A 20mA
Filter Error Amp Non-Inverting Input 30V -0.3V 1mA 1mA
Signal Common Signal Reference Input V(+VS) + 1V V(+VS) - 1V 1ma 1ma
Gnd Power Supply Return 0V 0V 1mA 10mA
SCR Trigger SCR Driver Output 30V -0.3V 1mA 1mA
+V

S

Shunt Regulator Supply Input 30V -0.3V 1mA 1mA
Amp

OUT

Error Amp Output 30V -0.3V 1mA 1mA
Detect Ground Fault Detect Input 6V -0.3V 10mA 10mA

Electrical Characteristics:

TA= 25¡C.

For ease of testing and improved test accuracy, Signal Common is grounded and a negative voltage is applied to the Gnd pin.

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

CS294

2

Absolute Maximum Ratings

Pin Symbol Pin Name V

MAX

V

MIN

I

SOURCE

I

SINK

Operating Junction Temperature, TJ. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150¡C

Lead Temperature Soldering:

Wave Solder (through hole styles only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Sec. max 260ûC Peak

Reflow (SMD styles only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 sec. max above 183¡C, 230¡ peak

Storage Temperature Range, TS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -65¡C to 150¡C

Supply Current +V

S

1.2 mA
Negative Supply Voltage Clamp -14.1 -11.9 -9.7 V
Positive Supply Voltage Clamp 9.7 11.9 14.1 V
Output Offset Voltage -400 67 +1100 mV
Output Resistance I(SCR Trigger) = 100µA 2.89 4.70 6.78 k½
Negative Amp Output Swing -10.95 -8.5 V
Positive Amp Output Swing 8.5 11.5 V
Positive Detect Threshold 5.9 6.5 7.2 V
Negative Detect Threshold -7.2 -6.5 -5.9 V
Detect Leakage Current V(SCR Trigger) = 0V 0.5 5.0 µA
Amplifier Open Loop Gain V(VFB) = 1mV RMS @ 50kHz 20 90 V/V
Operating Temperature Range TA(Note 1) 0 70 ¡C

Note 1: Guaranteed by design.