SAP51C-B-G1-R ZMDI, SAP51C-B-G1-R Datasheet - Page 32

• Manufacturer Part Number: SAP51C-B-G1-R
• Description: Interface - Specialized ASI
• Manufacturer: ZMDI

Specifications of SAP51C-B-G1-R

• Rohs: yes
• Product Type: Actuator Sensor Interface IC
• Operating Supply Voltage: 16 V to 34 V
• Supply Current: 6 mA
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: SOP-16
• Minimum Operating Temperature: - 25 C

4.5. AS-i Receiver
The receiver detects (telegram) signals at the AS-i line, converts them to digital pulses and forwards them to
the UART for further processing. The receiver is internally connected between the LTGP and LTGN pins.
Functional, the receiver removes the DC value of the input signal, band-pass filters the AC signal and extracts
the digital output signals from the sin
pulse determines the threshold level for all following pulses. This amplitude is digitally filtered to guarantee
stable conditions and to suppress burst spikes. This approach combines a fast adaptation to changing signal
amplitudes with a high detection safety. The comparators are reset after every detection of a telegram pause
at the AS-i line.
When the receiver is turned on, the transmitter is turned off to reduce the power consumption.
Table 18: Receiver Parameters
4.6. AS-i Transmitter
The transmitter draws a modulated current between LTGP and LTGN to generate the communication signals.
The shape of the current corresponds to the integral of a sin
DAC and a high current driver. The driver requires a small bias current to flow. The bias current is ramped up
slowly a certain time before the transmission starts so that any false voltage pulses on the AS-i line are
avoided.
When the transmitter is turned on, the receiver is turned off to reduce the power consumption. The SAP5
comprises a Clock Watchdog that becomes activated once the clock signal is stopped for about 100µs …
150µs. Thus, the transmitter is prevented from being permanently switched on in case the clock signal is
missing.
Table 19: Transmitter Current Amplitude
Data Sheet
October 20, 2011
Symbol Parameter
V
V
Symbol Parameter
I
SIG
SAP5S / SAP51
Universal Actuator-Sensor Interface IC
SIG
LSIGon
The IC determines the
amplitude of the first
negative pulse of the
AS-i telegram. This
amplitude is asserted
to be V
AC signal peak-peak amplitude (between LTGP and LTGN)
Receiver comparator threshold level (refer to Figure 5)
Modulated transmitter peak current swing (between LTGP and
LTGN)
SIG
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/ 2.
DC level
Figure 5: Receiver comparator threshold set-up in principle
2
-shaped input pulses by a set of comparators. The amplitude of the first
First negative
AS-i telegram
pulse of the
V
LSIGon
2
-function. The transmitter comprises a current
V
LSIGon
= (0.45 ... 0.55) * V
Min
Min
45
55
3
V
SIG
Max
Max
55
68
/ 2
8
Unit
Unit
mA
%
V
SIG
/ 2
amplitude of
32 of 63
Related to
1st pulse
Note
Note