MC145010ED View Datasheet(PDF) - Freescale Semiconductor

Part Name

Description

Manufacturer

MC145010ED

PHOTOELECTRIC SMOKE DETECTOR IC WITH I/O

Freescale Semiconductor 

Table 5. Configuration of Pins in the Calibration Mode

Description

Pin

Comment

I/O

Low-Supply Trip

7 Disabled as an output. Forcing this pin high places the photo amp output on pin 1 or 2, as determined by

Low-Supply Trip. The amp's output appears as pulses and is referenced to VDD.

15 If the I/O pin is high, pin 15 controls which gain capacitor is used. Low: normal gain, amp output on pin 1.

High: supervisory gain, amp output on pin 2.

Feedback

10 Driving this input high enables hysteresis (10% gain increase) in the photo amp; pin 15 must be low.

OSC

12 Driving this input high brings the internal clock high. Driving the input low brings the internal clock low. If

desired, the RC network for the oscillator may be left intact; this allows the oscillator to run similar to the

normal mode of operation.

Silver

9 This pin becomes the smoke comparator output. When the OSC pin is toggling, positive pulses indicate that

smoke has been detected. A static low level indicates no smoke.

Brass

8 This pin becomes the smoke integrator output. That is, two consecutive smoke detections are required for

ON (static high level) and two consecutive no-detections for “off” (static low level).

Do Not Run Any

Additional Traces

In This Region

Pin 16 Pin 1

C1

R14

R11

R8

D2

MOUNTED IN

CHAMBER

Pin 9 Pin 8

NOTES:

Illustration is bottom view of layout using a Dip. Top view for SOIC layout is mirror image. Optional potentionmeter R9 is not illustrated.

Drawing is not to scale.

Leads on D2, R11, R8, and R10 and their associated traces must be kept as short as possible. This practice minimizes noise pick-up.

Pin 3 must be decoupled from all other traces.

Figure 9. Recommended PCB Layout

MC145010

10

Sensors

Freescale Semiconductor

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