AMIS-49250-XTD ON Semiconductor, AMIS-49250-XTD Datasheet - Page 11

• Manufacturer Part Number: AMIS-49250-XTD
• Description: IC TXRX FIELDBUS MAU 44-NQFP
• Manufacturer: ON Semiconductor
• Type: Transceiverr

Specifications of AMIS-49250-XTD

• Number Of Drivers/receivers: 1/1
• Protocol: MDS-MAU
• Voltage - Supply: 4.75 V ~ 6.2 V
• Mounting Type: Surface Mount
• Package / Case: 44-LQFP
• Logic Type: Fieldbus Media Access Unit
• Logic Family: AMIS-492x0
• Number Of Channels Per Chip: 1
• Input Level: CMOS
• Output Level: CMOS
• Output Type: Open Drain
• High Level Output Current: 50 uA
• Low Level Output Current: 50 uA
• Supply Voltage (max): 6.2 V
• Supply Voltage (min): 3 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Polarity: Inverting/Non-Inverting
• Number Of Transmitters: 1
• Power Supply Requirement: Dual
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 44
• Operating Temperature (max): 85C
• Operating Temperature (min): -40C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: AMIS-49250-XTDOS

AMIS-492x0
4.0 Theory of Operation
4.1 Overview
The AMIS-492x0 incorporates two different power supply circuits.
configuration, the shunt regulator is set for 5V and the series regulator is set for 3V. Users can modify either power supply by adding
external components. The AMIS-492x0 Fieldbus can also monitor these power supply voltages and generate power-fail signals if they
fall below a specified value. Please refer to the AMIS-492x0 Fieldbus MAU Reference Design Application Note for ways to adjust the
shunt and series voltage regulators.
The AMIS-492x0 Fieldbus MAU transmits a Manchester-encoded signal provided from a standard MDS-MAU interface. The output
driver makes it possible to design various signal circuits, which depend on the power requirements of your device. The slew rate of the
signal can be controlled to minimize unnecessary radiation as specified in IEC/ISA standards.
The AMIS-492x0 Fieldbus MAU has a built-in band pass filter which makes it easy to design your own receiver. The receive block
operates on a Manchester-encoded signal. It decodes the signal and verifies proper amplitude with a zero-cross and carrier detect
circuit, respectively. Detected signals are then passed on to a controller with the standard MDS-MAU interface.
4.2 Power Supply Block
The power supply block contains four sub-blocks:
4.2.1. Shunt Regulator
The shunt regulator controls its sink current to the SHUNT pin so that the voltage applied to the SHSETIN pin is equal to V
input is divided by an internal network to provide a voltage equal to Vref at the SHSET pin. If SHSET and SHSETIN pins are tied
together, and V
shunt regulator provides 5V power to itself and external circuits. A capacitor of 5μF or larger capacity is necessary to stabilize this
regulator. Figure 13 shows C10 (22μF) connected to Pin 8 to accomplish stabilization.
It is possible to increase the V
SHSETIN pin. In this case, SHSET pin must be kept open. The output voltage is determined by the following equation:
1.
2.
3.
4.
A shunt regulator - for establishing a supply voltage of V
A series regulator - for establishing a supply voltage of V
Two low voltage detectors - for monitoring the two supply voltages
A bandgap voltage reference - which is used internally for generating a bias level for AC signals
CC
7
and SHUNT pins are connected to a power source of high impedance (e.g., current mirror circuit of signal driver), the
SHSET
( Internal Configuration )
Rsh
3 . 25 Rsh
VREF
Shunt Regulator
6
SHSETIN
CC
A 6
voltage up to 6.2V by dividing V
16 Meg
50 pF
Cfb
9
SGND
25 mA
( Max )
Rev. 6 | Page 11 of 22 | www.onsemi.com
SHUNT
18
VCC
8
V
CC
System
Figure 4: Shunt Regulator
VCC
= V
CC
REF
DD
(typ. = 5V) used by the analog circuitry
(typ. = 3V) used for digital circuitry
× (1 + R
CC
with an external network to supply the appropriate voltage to
Both derive their power from the bus.
N/C
7
1
/ R
SHSET
(External Configuration )
2
)
3.25Rsh
Rsh
VREF
Shunt Regulator
6
SHSETIN
A6
16Meg
50 pF
Cfb
9
SGND
25 mA
( Max )
SHUNT
18
VCC
8
System
VCC
Using the internal
REF
R2
R1
. The V
CC