3.

Time delays and obtaining CRs

When input signals that have been applied at a level not less than –45 dBm are removed, discharging occurs through the CR

connected at pin 2, lowering pin 2 potential. A time delay is provided before the hysteresis comparator turns over.

E1

E0

=−

t

e

τ

E0 : Initial voltage

E1 : Threshold voltage

τ : Time constant

Accordingly,

t=−

τIn

E1

E0

E1/E0, within the IC, is 0.26. A desired time is obtained by an appropriate choice of

τ (τ = C3R1). Therefore, the time delay is

obtained by the following formula:

t = 1.34

× C3R1 (sec)

We recommend 150 k to 500 k

Ω for R when determining CR.

4.

IC usage notes

.

Maximum ratings

When maximum ratings are surpassed, destruction or deterioration may result. Use the IC in the range where the maximum

rating is not exceeded.

.

Interpin short circuits and reverse insertions

These cause destruction or deterioration of the IC: be careful when mounting on circuit board.

.

Voltage applied to pin 8 should never exceed pin 9 voltage.

.

The current flowing into pin 8 is to be 0.5 mA maximum.

.

Pin 4 is unconnected, but is not to be used for GND or an interconnecting terminal.

Duty cycle – %

Pd max – Ta

Ambient temperature, Ta – °C

Ta = 60°C

or lower

LA2000

No.982-3/8