Z8FS040 datasheet(21/56 Pages) ZILOG

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ZMOTION

TM Detection and Control Family

Product Specification

PS028506-1110

PRELIMINARY

Hardware Connection Requirements

This section describes the required external hardware connection for the ZMOTION

TM MCU Series.

Pins are automatically configured to their required function when the PIR engine is initialized via the

EPIR_INIT macro.

See

Appendix A for example schematic diagrams showing the required connections.

The device can be operated in Single Pyro mode supporting one Pyroelectric sensor or Dual Pyro

mode supporting two Pyroelectric sensors. Both of these modes can be operated in Normal or Low

Scan Rate modes.

Depending on the application, there can be up to 3 connection requirements supporting these modes:

1. Pyroelectric Sensor (PIR Sensor)

The signal from the PIR sensor is connected directly to the ANA2 input of the ADC. The ADC

is configured for differential, buffered mode by Zilog’s PIR technology. The sensor signal

should be connected directly to the ADC input with no additional signal conditioning circuitry

unless specified by the pyroelectric sensor manufacturer.

2. ADC VREF

The on chip VREF is configured for 1V nominal. The PIR Sensor signal is connected to the ‘+’

differential input of the ADC (ANA2) and the VREF signal is connected to the ‘-‘ differential input

(ANA3). The 8 pin device has an internal connection from VREF to ANA3 to support this

configuration therefore no external hardware connection is required. The 20 and 28 pin

devices require an external connection from the VREF out signal to the ADC ‘-‘ (ANA3) input.

3. Pyroelectric Passive Infrared Sensor #2

In Dual Pyro mode, the ADC is still used in differential, buffered mode (same as Single Pyro

mode). The signal from the second PIR sensor is connected to ANA3. The VREF signal is no

longer connected to ANA3 (‘-‘ ADC input). The fist PIR sensor is connected to the ‘+’ ADC

input (ANA2) as it is in Single Pyro mode. The VREF signal is still used internally for the ADC,

but the external pin is unused in Dual Pyro mode.

Z8FS040 数据表(PDF) 21 Page - Zilog, Inc.