Absolute Maximum Ratings

If MilitaryAerospace specified devices are required

please contact the National Semiconductor Sales

OfficeDistributors for availability and specifications

Supply Voltage Va (Pin 12)

18V

Power Dissipation (Note 1)

1700 mW

Peak Current (Pins 6 14)

1A

Input Current (Pins 4 8)

50 mA

Operating Temperature

0 Cto a70 C

Storage Temperature Range

b

65 Cto a150 C

Lead Temperature (Soldering 10 sec)

260 C

Electrical Characteristics Va e 12V TA e 25 C unless otherwise noted

Parameter

Conditions

Min

Typ

Max

Units

Input Sensitivity (Note 2)

Figure 2

200

600

m

Vp-p

Input Noise

10

m

Vp-p

Transmitter Output VSAT

I6 e 1A

13

3

V

Transmitter Output Leakage

V6 e 36V

001

1

mA

V8 e 0V

Detector Output VSAT

I14 e 1A

15

3

V

Detector Output Leakage

V14 e 36V

001

1

mA

Transmitter Key Threshold

I8 e 1 mA

055

07

09

V

Supply Current

I1 a I12

5

85

20

mA

Receive Mode

V8 for Receive Mode

03

V

Maximum Operating Frequency

Transmit Mode

200

325

kHz

Note 1

For operating at high temperatures the LM1812 must be derated based upon a 125 C maximum junction temperature and a thermal resistance of

58 C CW which applies for the device soldered in a printed circuit board and operating in a still air ambient Due to the low duty cycle operation only a small

average power is dissipated in the package

Note 2

A 47k resistor is added in parallel with the receiver tank at pin 1 to swamp variations in the coil’s unloaded Q The resistor reduces sensitivity (see equation

4) and is unnecessary in an actual applications circuit

Test Circuit

TLH7892 – 2

fIN e 200 kHz

Input sensitivity e minimum VIN for VO to go low

FIGURE 2 Sensitivity Test Circuit

2