RE46C180 datasheet(22/58 Pages) MICROCHIP

Part #	RE46C180

Description	CMOS Programmable Ionization Smoke Detector ASIC with Interconnect, Timer Mode and Alarm Memory

PDF	58 Pages

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Manufacturer	MICROCHIP [Microchip Technology]

Direct Link	http://www.microchip.com

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22 / 58 page

RE46C180

DS20002275C-page 22

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2011-2021 Microchip Technology Inc.

4.3

Serial Read/Write Calibration

As an alternative to the steps in

Section 4.2, Smoke

Calibration, the sensitivity settings can be entered

directly from a Serial Read/Write Calibration mode (if

the system has been well characterized).

To enter this mode, follow these steps:

1. Power-up with the bias condition shown in

Figure 4-1 to enter M0. At power-up:

TEST = IO = FEED = T2 = VSS,

DETECT = VDD,

2. Drive T2 input from VSS to VDD and hold at VDD

to enter TM0.

3. Drive TEST from VSS to VDD and hold at VDD.

4. Apply 10 clock pulses to the T2 input (VDD to

VSS and back to VDD) to enter in TM10 mode.

This enables the Serial Read/Write Calibration

mode.

5. TEST now acts as a data input (High = VDD,

Low = VSS). FEED acts as the clock input

(High = VDD, Low = VSS). Clock in the sensitivity

settings.

The data sequence should be as follows:

6. After all 17 bits have been entered, pulse IO to

store into the EEPROM memory. Power-down

the part to take effect.

5 bit

Standby Sensitivity (LSB first)

3 bit

Hysteresis (LSB first)

4 bit

HUSH Sensitivity (LSB first)

5 bit

CHAMBER voltage in PTT/Chamber

Test (LSB first)

RE46C180 Datasheet(PDF) 22 Page - Microchip Technology