ON Semiconductor NCN5150SOICGEVB User manual

©Semiconductor Components Industries, LLC, 2013
March, 2013 −Rev. 0
1Publication Order Number:
EVBUM2178/D
NCN5150NGEVB
NCN5150 Evaluation Board
User's Manual
Introduction
The NCN5150SOICGEVB and NCN5150QFNGEVB
evaluation boards demonstrate the NCN5150 M-BUS
transceiver in SOIC and QFN package respectively. These
evaluation boards include all external components needed
for operating NCN5150 and demonstrate the small PCB
surface area such an implementation requires.
Overview
The NCN5150 is a single-chip integrated slave
transceiver for use in two-wire Meter Bus (M-BUS) slave
devices and repeaters. The transceiver provides all of the
functions needed to satisfy the European Standards EN
13757−2 and EN 1434−3 describing the physical layer
requirements for M-BUS. It includes a programmable
power level of up to 2 (SOIC version) or 6 (NQFP version)
unit loads, which are available for use in external circuits
through a 3.3 V LDO regulator. The NCN5150 can provide
communication up to the maximum M-BUS
communication speed of 38,400 baud (half-duplex).
Applications
Multi-energy Utility Meters
•Water
•Gas
•Electricity
•Heating Systems
Features
•Single-chip MBUS Transceiver
•UART Communication Speeds Up to 38,400 baud
•Integrated 3.3 V VDD LDO Regulator with Extended
Peak Current
•Capability of 15 mA
•Supports Powering Slave Device from the Bus or from
External Power Supply
•Adjustable I/O Levels
•Adjustable Constant Current Sink up to 2 or 6 Unit
Loads Depending on the Package
•Low Bus Voltage Operation
•Extended Current Budget for External Circuits:
minimum 0.8 mA
•Polarity Independent
•Power-Fail Function
•Fast Startup −No External Transistor Required on STC
Pin
•Industrial Ambient Temperature Range of −40°C to
+85°C
•Available in:
♦16-pin SOIC (Pin-to-Pin Compatible with
TSS721A)
♦20-pin QFN
•These are Pb-free Devices
Figure 1. The NCN5150NGEVB Evaluation Boards
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EVAL BOARD USER’S MANUAL

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ELECTRICAL CHARACTERISTICS
Table 1. ELECTRICAL CHARACTERISTICS OF THE NCN5150SOICGEVB AND NCN5150QFNGEVB BOARD
Symbol Parameter / Condition
Value
Unit
Min Typ Max
Bus Voltage
VBUS Bus Voltage 12 36 42 V
Current Drawn from the Bus
IBUS 1 UL 1.3 1.5 mA
Output Voltage
VDD LDO output 3.1 3.3 3.6 V
NCN5150 DESCRIPTION
The NCN5150 provide a complete transceiver for the
Metering Bus (M-BUS).It consists of a transmit block
which will translate the logic level uart input to current level
signaling on the bus, and a receive block which will translate
the voltage-level signaling on the bus to a logic-level uart
output. The device includes an echo function which will
echo the uart input on the uart output, provided the device is
powered. This can be used by the software stack to monitor
if the message was transmitted. The high voltage level of the
microcontroller interface can be changed by connecting the
desired voltage to the VIO pin. By default, this pin is
connected through a 0R resistor to 3.3 V on the evaluation
boards.
A constant current regulator that will draw a fixed current
from the bus, expressed in unit loads (UL). This current is
made available to the application through a low-dropout
3.3 V regulator. The NCN5150 will detect when the bus is
disconnected and provide an early warning to the
microcontroller that the 3.3 V supply is about to collapse
through the PFb pin.
A thermal shutdown protects the device against high
junction temperatures.
NCN5150SOICGEVB DESCRIPTION
General Overview
The NCN5192NGEVB evaluation board demonstrates
the external components required for the operation of the IC.
We will cover the different sections below as well as possible
alternatives. A drawing of the board where the different
sections are indicated is shown below.
Figure 2. Board Drawing with Indication of Different Sections
Loop I/F
NCN5150
UART I/F
STC Capacitor
Test I/F
Loop I/F

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BOM List
Table 2. NCN5150SOICGEVB BILL OF MATERIALS
Quantity Reference Part Footprint Comments Manufacturer Product Code
1 C1 1u C0603 6V3 Multicomp MCCA000515
1 C2 DNP C0603 DNP − −
5R3, R5, R9, R12,
R13
DNP R0603 DNP − −
1 C3 100n C0603 50 V Multicomp MCCA000256
1 C4 220u Case E 10 V AVX TAJD227K010RNJ
1 D1 1SMA40CAT3G SMA ON Semiconductor 1SMA40CAT3G
2 J1,J5 CON2 DNP IMO Precision 21.95MH/2
3 J2,J3,J4 CON10A DNP Multicomp 2214S−10SG−85
2 Q1,Q2 DNP SOT−23 DNP − −
4R1, R4, R10, R15 0R R0603 62.5 mW Multicomp MC0603WG00000T5E−TR
6R2, R6, R8, R11,
R14, R17
100R R0603 62.5 mW Multicomp MC0.063W06031%100RFR
2R7, R16 220R R0603 62.5 mW Multicomp MC0.063W06031%220RFR
1 R18 30K R0603 62.5 mW Multicomp MC0.063W06031%30KFR
1 TP1 GND DNP − −
1 TP2 3V3 DNP − −
1 U1 NCN5150 SOIC16 DNP ON Semiconductor NCN5150DR2G

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Schematic Diagram
Figure 3. Schematic of NCN5150SOICGEVB

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NCN5150QFNGEVB DESCRIPTION
General Overview
The NCN5150QFNGEVB evaluation board
demonstrates the external components required for the
operation of the IC. We will cover the different sections
below as well as possible alternatives. A drawing of the
board where the different sections are indicated is shown
below.
Figure 4. Board Drawing with Indication of Different Sections
Loop I/F
NCN5150
UART I/F
STC Capacitor
Test I/F
Loop I/F Test I/F
BOM List
Table 3. NCN5150QFNGEVB BILL OF MATERIALS
Quantity Reference Part Footprint Comments Manufacturer Product Code
1 C1 1u C0603 6.3 V Multicomp MCCA000515
1 C2 DNP C0603 DNP − −
1 C3 100n C0603 50 V Multicomp MCCA000256
1 C4 220u Case E 10 V AVX TAJD227K010RNJ
1 C5 DNP Case E DNP − −
4D1, D2, D4, D5 DNP SOD−123 DNP − −
1 D3 1SMA40CAT3G SMA ON Semiconductor 1SMA40CAT3G
4J1, J3, J4, J5 CON10A DNP IMO Precision 21.95MH/2
2J2, J6 CON2 DNP Multicomp 2214S−10SG−85
2Q1, Q2 DNP SOT−23 DNP − −
10 R1,R2,R3,R4,R5,
R8,R11,R13,R15,
R18
DNP DNP − −
6 R7,R9,R12,R16,
R19,R22
100R R0603 62.5 mW Multicomp MC0.063W06031%100RFR
4 R6,R14,R17,R20 0R R0603 62.5 mW Multicomp MC0603WG00000T5E−TR
2R10, R21 220R R0603 62.5 mW Multicomp MC0.063W06031%220RFR
1 R23 30K R0603 62.5 mW Multicomp MC0.063W06031%30KFR
1 TP1 GND DNP − −
1 TP2 3V3 DNP − −
1 U1 NCN5150 QFN20 ON Sample ON Semiconductor NCN5150MNTWG

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Schematic Diagram
Figure 5. Schematic of NCN5150QFNGEVB

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FUNCTIONAL DESCRIPTION
Power Supply
The NCN5150 provides power to be used in the
application. To do this, the NCN5150 draws a fixed current
from the bus. The amount of current drawn is fixed at a
number of unit loads (intervals of 1.5 mA) and can be set by
changing the value of the RIDD resistor. The SOIC version
can support up to 2 UL, while the QFN version can support
up to 6 UL. The required resistors for are shown in table xx.
Also shown in table xx is the maximum amount of
capacitance allowed on the STC pin. This limit will ensure
that the transceiver will start up in less than 3 s as required
by the M-BUS standard. Using a smaller capacitor on STC
is allowed, and will result in faster start-up, but also in a
faster shutdown, reducing the time between the early
warning PFb toggling (when the bus is removed) and the
point where the 3.3V VDD voltage can no longer be
maintained. The minimum allowed capacitance on STC is
10 times the capacitance on the VDD pin. The minimum
required capacitance on the VDD pin is 1 mF.
Table 4. UL, RIDD VALUES, STC CAPACITANCE
Number of
Unit Loads
RIDD
Value
Maximum STC
Capacitor Value
Min. Avail-
able Current
130 kW330 mF0.88 mA
213 kW820 mF2.10 mA
38.45 kW1200 mF3.10 mA
46.19 kW1500 mF4.20 mA
54.87 kW2200 mF5.30 mA
64.02 kW2700 mF6.50 mA
Shown in Figure 6 is the startup sequence of the device.
Note that the NCN5150 does not require any external
(PMOS) transistor on the STC pin for proper startup. The
yellow waveform is the bus voltage, the purple waveform
the STC voltage, the green waveform the VDD output, and
the blue waveform the TX output.
Figure 6. NCN5150 Startup Sequence
Shown in Figure 7 is the shutdown sequence of the device.
The green waveform is the bus voltage, the blue waveform
is the VDD output, the purple waveform is the PFb output,
and the yellow waveform is the TX output.

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Figure 7. NCN5150 Shutdown Sequence
UART Interface IDC1
The interface between the transceiver and an external
microcontroller is a standard uart interface consisting of the
TX and RX. Alternatively, inverted signals, TXI and RXI,
which are active high, are also available. Only one signal
from TX and TXI, or from RX and RXI can be used at the
same time. The uart pins can handle communication up to
38400 baud. The M-BUS standard requires communication
with 1 start bit, 8 data-bits, 1 even parity bit and 1 stop bit.
Also available on the same connector is the VIO
connection, PFb indication and 3V3 VDD output.
Table 5. MICROCONTROLLER INTERFACE
Pin
number Signal Type Description
1 PFb Output Bus failure indication
2 VIO Power IO voltage level
3 RX Input UART input
5 RXI Input UART input, inverted
7 TX Output UART output
9 TXI Output UART output, Inverted
4, 6, 8 GND Power Ground
10 VDD Power 3V3 Output
Transmitter
The M-Bus transmitter translated the RX or RXI voltage
levels to current levels on the bus. Typically, 15 mA is added
when transmitting a space.
Figure 8. Output Waveforms
ISPACE = IMARK + 15 mA
IMARK = N unit loads
IBUS
VIO
VRX
t
VIO
VRXI
t
t
Receiver
The receiver will compare the bus voltage level with the
mark level stored on the SC capacitor minus the threshold
level (typically 6 V). It will translate these voltage levels to
low voltage communication on the TX and TXI pins. The
high voltage of these pins is determined by the VIO voltage.
Figure 9. Receive Waveforms
VMARK = [21V, 42V]
VSPACE = VMARK −12V
VT= VMARK – 6V
VBUS
VIO
VTX
t
VIO
VTXI
t
t

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APPENDIX
Evaluation Board Layout
Figure 10. Top Layer Layout (SOIC)
Figure 11. Bottom Layer Layout (SOIC)

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Figure 12. Top Layer Layout (QFN)
Figure 13. Bottom Layer Layout (QFN)