Siemens FZE1658G Datasheet

8 x Digital Sensor Interface

Features

● Input protection against 2000 V burst/500 V surge

pulse according to IEC 801 4/5

● Input characteristic according to IEC 65 A, type 2

(24 V DC)

● Digital filter

● Serial in/out for easy cascading

● Low power dissipation

● SMD package

Type Ordering Code Package

P-DSO-24-1

FZE 1658G

FZE 1658G Q67000-A8361 P-DSO-24-1

The FZE 1658G is an integrated interface for digital sensors - i.e. proximity switches - in industrial automation equipment. The IC has eight integrated highly protected and failsafe inputs with status LED and a serial synchronous output for direct MC-interfacing.

Semiconductor Group 1 01.97

Pin Configuration

(top view)

FZE 1658G

Semiconductor Group 2

Pin Definitions and Functions Pin Symbol Function

FZE 1658G

15, 13, 11, 9, 5, 3, 1, 23

16, 14, 12, 10, 6, 4, 2, 24

I0 - I7 Inputs for 24-V signals, in conjunction with

and R

EXT

current sink characteristic.

L0 - L7 Outputs for the status LEDs; LED lights when H-signal is

present at input.

21 CT Pin for connecting the frequency-determining capacitor for

the filter clock; also reset input if CT is connected to DGND 7 GND Ground for all 24-V signals, substrate. 22 DGND Ground for all 5-V signals, no internal connection to GND.

Any interruption of GND or DGND with the supply voltage

present may result in destruction of the device. 8

Supply voltage; undervoltage activates internal reset. 20 SO-N Serial output, open drain. 17 SE-N Extention input for serial cascading with pull-up current

source.

18 LO-N Latch input, edge H-L results in transfer of data from the

digital filters to the output register. 19

Clock for serial output, positive edge triggered.

Semiconductor Group 3

FZE 1658G

Functional Description and Application

The Integrated circuit FZE 1658G is used to detect the signal states of eight independent input lines according to IEC 65A Type 2 (e.g. two-wire proximity switches) with a common ground (GND). For operation in accordance with IEC 65A, it is necessary for the device to be wired with resistors rated tolerance and 200 ppm TK. The input device has the following characteristics:

– Minimization of power dissipation due to constant current characteristic – Inputs protected against reverse polarity and transient overvoltages – Status LED output for each input – Digital averaging of the input signals to suppress interference pulses – Serial output of the detected signals (cascadable)

Maximum voltage ratings at inputs D0 ... D7 within test circuit 2.

Voltage Range Notes

= 820 Ω and R

= 4.4 kΩ with ± 2%

EXT

DC voltage – 3 V … + 32 V

–32V … +32V

Overvoltage 500 ms – 3 V … + 35 V

–35V … +35V

Overvoltage 1.3 ms to VDE 0160

Surge pulse 50 µs to IEC 801-5,

= 2 Ω

Burst pulse 50 ns to IEC 801-4,

Non-destructive in temperature range 15 °C ≤ TA≤ 35 °C.

In temperature range 15 °C ≤ TA≤ 35 °C: Data retained if the supply voltage remains within the operating range; without supply voltage non-destructive.

= 50 Ω

– 3 V … + 55 V

± 55 ± 0.5 kV

± 2kV

full function non-destructive, no latch-up

The rated voltage may be applied to all inputs simultaneously. The values given in the table may be regarded as guaranteed, but are only checked as

part of a qualification (no 100 % series testing). Within the application circuit given the same voltage ratings as above apply for the

supply line.

Semiconductor Group 4

FZE 1658G

Circuit Description

In IEC 65A, the following values are specified for 24-VDC input stages of type 2:

Level Input Voltage Input Current

1 0

min. 11 V max. 11 V

min. 6 mA max. 2 mA

or max. 5 V

The current in the input circuit is determined by the switching element in state “0” and by characteristics of the input stage in state “1”.

The octal input device FZE 1658G is intended for a configuration comprising two specified external resistors per channel, as shown in the block diagram. As a result the power dissipation within the P-DSO-24-1 package is at a minimum.

The voltage dependent current through the external resistor

is compensated by a

EXT

negative differential resistance of the current sink across pins E and L, therefore input D behaves like a constant current sink.

The comparator assigns level 1 or 0 to the voltage present at input E. To improve interference protection, the comparator is provided with hysteresis and a delay element.

A status LED is connected in series with the input circuit (R

and current sink). The

EXT

LED drive short-circuits the status LED if the comparator detects “0”. A constant current sink in parallel with the LED reduces the operating current of the LED, and a voltage limiter ensures that the input circuit remains operational if the LED is interrupted. The specified switching thresholds may change if the LED is interrupted.

For each channel a digital filter is provided which samples the comparator signal at a rate provided by the clock oscillator. The digital filter is designed as a 5-section shift register. If any four out of 5 sampling values are identical, the output S changes to the corresponding state.

On a falling edge at input LO-N, the parallel data S0 - S7 are clocked into the output shift register. The data can be shifted out serially to the output SO-N by the clock signal T, with a “1” at the input being represented by a L-signal at the output SO-N. The serial interface of the shift register fits the synchronous interface of the 8051 microcontroller (see diagram Serial Data Output Function). By connecting output SO-N to input SE- N of the next device, several FZE 1658G can be cascaded (see Application Circuit). SO-N is designed as an open-drain output. SE-N has an internal pull-up current source. Inputs SE-N, T and SO-N have Schmitt trigger characteristics. The device has separate ground pins for the input circuitry (GND) and for the logic (DGND). If the supply voltage falls below

or CT is connected to DGND, the output shift register will be cleared and

USR

the output SO-N disabled. If the supply voltage is too low, the LED drives will also be disabled, i.e. the LED lights as soon as current flows in the input circuit.

Semiconductor Group 5

FZE 1658G

Block Diagram

Semiconductor Group 6

+ 12 hidden pages