Optical MOSFET

One of the characteristics of optical MOSFETs is the CxR. What kind of characteristic is that?

When using optical MOSFETs for relays, the CxR indicates the quality of the characteristics of the high-frequency signal. The CxR has the following contents and features.

→ When this capacitance is large, the high-frequency signal passes through even during relay off.

→ When this resistance is large, signal loss, etc., may occur.

In other words, the smaller the CxR, the better the characteristics of the high-frequency signal.

(2007/10)

What is the on-resistance value of an optical MOSFET?
Regarding the resistance values in the PS7122A-1B data sheet
(1) On-resistance 4.5 Ω (TYP.) is the value of which one of the following connections?



(2) What is the resistance value for connections other than (1)?

(1): Connection A
(2): Connection B: 1/2 of A; Connection C: 1/4 of A

(2007/10)

Two types of on-state resistances are shown in the electrical specifications of the PS7160-1A Data Sheet. How do they differ?

[Example of PS7160-1A]

A product with a high on-state resistance has a tendency whereby the on-state resistance decreases when the load current (I_L) is large. Therefore, the on-state resistance is defined under two conditions: in a low current region and a high current region.

The on-state resistance of the PS7160-1A in the low current region (condition: I_L = 10 mA) is defined as Ron1 and the on-state resistance in the high current region (condition: I_L = 90 mA, 10 ms ≥ t) is defined as Ron2.

For details, see "Explanation of optical-coupled MOS FET (OCMOS FET) Specifications — "ON" state Resistance: Ron (Ω)".

(2008/02)