NCN5151MNTWG [ONSEMI]
Wired M-BUS Slave Transceiver;
| 型号： | NCN5151MNTWG |
| 厂家： | 
ONSEMI |
| 描述： | Wired M-BUS Slave Transceiver |
| 文件： | 总20页 (文件大小：174K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
NCN5151
Wired M-BUS Slave
Transceiver with Low
Power Mode Support
Description
www.onsemi.com
The NCN5151 is a single−chip integrated slave transceiver for use
in two−wire Meter Bus (M−BUS) slave devices and repeaters.
The NCN5151 reuses the NCN5150 features and adds two low
power modes: a 2−wire low power mode dedicated to System for
meter Communication and Readout for powerless meters (SCR) and a
3−wire low power mode allowing support for wireless applications.
When configured in low power mode, the transceiver will not behave
anymore as a constant current source in order to save energy.
When configured and used in M−BUS mode, the NCN5151
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 6 unit loads, which are available for use in
external circuits through a 3.3 V LDO regulator.
NQFP−20
MN SUFFIX
CASE 485E
MARKING DIAGRAMS
20
1
NCN
5151
ALYW
G
Features
A
L
Y
W
G
= Assembly Location
= Wafer Lot (optional)
= Year
= Work Week
= Pb-free Package
• Single−chip M−BUS Transceiver
• 2 and 3−Wire Low Power Modes with Selection Input Pins
• Integrated 3.3 V VDD LDO Regulator with Extended Peak Current
Capability of 15 mA
• Supports Powering Slave Device from the Bus
• Adjustable Constant Current Sink Up to 6 Unit Loads in M−Bus
Mode
ORDERING INFORMATION
See detailed ordering and shipping information on page 19 of
this data sheet.
• Adjustable Current Limit up to 2 Unit Loads in Low Power Mode
• Current budget of 0.88 mA minimum for external circuits
• Low Turn−ON/OFF Levels for Low Bus Voltage Operation
• Polarity Independent
• Power−Fail Function (M−Bus mode)
• UART Communication Speeds up to 38400 baud
• Fast Startup − No External Transistor Required on STC Pin
• Industrial Ambient Temperature Range of −40°C to +85°C
• These are Pb-free Devices
Typical Applications
• Multi−Energy Utility Meters
♦ Water
♦ Gas
♦ Electricity
♦ Heating systems
Related Standards − European Standard
EN 13757−2, EN 1434−3
For more information visit www.m-bus.com
© Semiconductor Components Industries, LLC, 2015
1
Publication Order Number:
April, 2015 − Rev. 2
NCN5151/D
NCN5151
16
20 19
18 17
GND
1
2
3
4
5
15
14
13
12
11
3WLPM
NC
BUSL1
NCN5151
VIO
BUSL2
VB
QFN20
TX
PMODE
TXI
6
7
8
9
10
Figure 1. Pin Out NCN5151 in 20−pin NQFP
(Top View)
Table 1. NCN5151 PINOUT
Signal Name
GND
Type
Ground
Bus
Pin Number
Pin Description
1
2
3
4
5
6
Ground
BUSL1
BUSL2
VB
Bus line. Connect to bus through series resistors. Connections are polarity
independent.
Bus
Power
Output
Output
Rectified bus voltage
PMODE
STC
Power Mode output indicating the voltage level on VB pin
Storage capacitor pin. Connect to bulk storage capacitor (typically 100 mF − 470 mF,
minimum 10 mF).
RIDD
Input
7
Mark current adjustment pin.
Connect to programming resistor.
PF
SC
Output
Output
8
9
Power Fail, active low (disabled in low power mode)
Mark bus voltage level storage capacitor pin. Connect to ceramic capacitor (typically
220 nF).
2WLPM
TXI
Input
Output
Output
Input
−
10
11
12
13
14
15
16
17
18
19
2−Wire Low Power Mode selection input
UART Data output (inverted)
TX
UART Data output
VIO
I/O pins (RX, RXI, TX, TXI, PF) high level voltage
Leave this pin floating.
NC
3WLPM
VDD
RX
Input
Power
Input
Input
Output
3−Wire Low Power Mode selection input
Voltage regulator output. Connect to minimum 1 mF decoupling capacitor.
UART Data input
RXI
UART Data input (inverted)
OD
Open Drain output (active low). Used for the slave to master communication in 3−Wire
Low Power mode
RIS
Input
20
Modulation current adjustment pin
www.onsemi.com
2
NCN5151
PF
8
19
OD
VIO_BUF
13
VIO
3−Wire LPM
Transmitter
VIO
Buffer
LP_TX
Power
Fail
VB_INT
5
4
VB
2
BUSL1
PMODE
VB
Monitor
Detect
CS1
3
9
STC
BUSL2
SC
Clamp
7
6
RIDD
STC
VIO_BUF
11
12
STC
16
TXI
TX
Voltage
Monitor
VDD
Receiver
3.3 V
LDO &
POR
ECHO
17
18
10
15
RX
LP_TX
2WLPM
3WLPM
Transmitter
Low
Power
Logic
LP_CTL
RXI
CS_TX
Thermal
NCN5151
Shutdown
1
20
RIS
PC20130527.1
GND
Figure 2. NCN5151 Block Diagram
www.onsemi.com
3
NCN5151
Table 2. ABSOLUTE MAXIMUM RATINGS
Symbol
Parameter
Min
−40
−55
−50
−0.3
−0.3
Max
+150
+150
50
Unit
T
T
Junction temperature
°C
J
Storage temperature
°C
V
S
V
Bus voltage (|BUSL1 − BUSL2|)
Voltage on pin TX, TXI
BUS
V
, V
TXI
7.5
V
TX
V
RX
, V
RXI
,
Voltage on pin RX, RXI, VIO
5.5
V
V
IO
V
Voltage on pin OD
−0.3
−0.3
−0.3
−0.3
4.0
40
3.6
3.6
3.6
−
V
V
OD
V
V
Voltage on pin 3WLPM
Voltage on pin 2WLPM
Voltage on pin PMODE
ESD Rating − Human Body Model
ESD Rating − Machine Model
3WLPM
2WLPM
PMODE
V
V
V
ESD
kV
V
HBM
ESD
250
750
−
MM
ESD
ESD Rating − Charged Device Model
−
V
CDM
Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality
should not be assumed, damage may occur and reliability may be affected.
1. All voltages are referenced to GND.
Table 3. THERMAL CHARACTERISTICS
Symbol
Rating
Typical Value
Unit
R
Thermal Characteristics, QFN−20
38
°C/W
q
JA
Thermal Resistance, Junction−to−Air
R
obtained with 2S2P test boards according to JEDEC JESD51 standard.
q
JA
Table 4. RECOMMENDED OPERATING CONDITIONS (Note 2)
Symbol
Parameter
Min
Max
+85
42
Unit
°C
V
T
A
Ambient Temperature
Bus voltage (|V −V
−40
9.2
9.7
4.75
3.8
2.5
0
V
BUS
|)
M−Bus mode
1−2 U
3−6 U
1−2 U
BUSL1
BUSL2
L
L
L
42
V
2 and 3−Low Power Mode
10
V
V
VSTC in Low Power Mode to guarantee min V of 3.1 V @ I = 15 mA peak
V
STC,LP
DD
DD
V
IO
VIO pin voltage (Note 3)
OD pin voltage (Note 3)
3.8
10
V
V
OD
V
ESD−HBM Human Body Model (EIA−JESD22−A114−B)
ESD−MM Machine Model (JEDEC JESD22−A115)
ESD−CDM Charged Device Model (EIA−JESD22−C101−A)
LU Latch−up (EIA/JESD78)
4
kV
V
200
750
100
V
mA
2. Refer to ELECTRICAL CHARACTERISTIS and APPLICATION INFORMATION for Safe Operating Area.
3. All voltages are referenced to GND
www.onsemi.com
4
NCN5151
Table 5. M−BUS MODE − ELECTRICAL CHARACTERISTICS (Notes 4 and 5)
Symbol
Parameter
Min
Typ
Max
Unit
V
ΔV
Voltage drop over bus rectifier (V
Voltage drop over CS1 (V − V
STC
− V ) with R
= 4.02 kW
1.25
BR
BUS
B
IDD
ΔV
)
1.30
1.70
V
R
≤ 13 kW
CS
B
IDD
IDD
IDD
IDD
IDD
IDD
IDD
IDD
R
≤ 4.02 kW
= 30 kW
I
Total current drawn from the bus, in Mark State
1.30
2.70
4.10
5.50
6.80
8.20
0.2
1.50
3.00
4.50
6.00
7.50
9.00
2
mA
R
BUS
R
= 13 kW
R
= 8.45 kW
= 6.19 kW
= 4.87 kW
= 4.02 kW
R
R
R
ΔI
BUS
Bus current stability (over ΔV
= 10 V, RX/RXI = mark)
%
BUS
I
Idle current available for the application to draw
from STC and V (including current drawn from
0.88
2.10
3.10
4.20
5.30
6.50
−
1.00
2.30
3.60
4.80
6.10
7.40
250
1.20
2.60
4.00
5.40
6.90
8.40
−
mA
R
R
R
R
R
R
= 30 kW
STC
IDD
IDD
IDD
IDD
IDD
IDD
DD
= 13 kW
V
DD
)
= 8.45 kW
= 6.19 kW
= 4.87 kW
= 4.02 kW
DI
Additional current available for the application when transmitting a space
Threshold voltage on V to trigger PF
mA
STC,SPACE
V
V
STC
V
STC
+
V
B,PF
B
+0.3
0.8
V
PF voltage high (I = −100 mA)
V
0.6
−
V
IO
V
V
PF,OH
PF
IO
V
PF, OL
PF voltage low (Note 6) (I = 50 mA)
0
0.6
PF
4. All voltages are referenced to GND
5. R resistor with 1% accuracy
IDD
6. PF pin is pulled down with an on−chip resistor of typically 2 MW
Table 6. LOW POWER MODE − ELECTRICAL CHARACTERISTICS (Note 7)
Symbol
Parameter
− V ) with I = 3 mA and external
BUS
Min
Typ
Max
Unit
ΔV
Voltage drop over bus rectifier (V
Schottky diodes (Note 8)
0.35
V
BR,LP
BUS
B
I
Max Current available for the application to draw
from STC and VDD (including current drawn
2.0
4.1
9.4
2.3
4.8
2.7
5.5
mA
V
R
(Note 9) = 30 kW
STC,LP
IDD
(Note 9) = 13 kW
from V ) (Note 10)
DD
V
Clamp voltage on pin STC (I < I ) (Note 11)
STC
10.5
11.5
STC,CLAMP,LP
DD
7. All voltages are referenced to GND
8. Forward voltage of 0.3 V max
9. Resistor with 1% accuracy
10.When configured in low power mode, the current limit of CS1 is set to 2 x the mark current level in M−BUS mode. The NCN5151 does not
behave as a current source but as current limiter because V never reaches the STC clamp level.
STC
11. The STC clamp function protects the STC capacitor in case 2WLPM or 3WLPM is accidentally enabled during regular M−Bus operation.
Table 7. GENERAL − ELECTRICAL CHARACTERISTICS (Note 12)
Symbol
Parameter
Min
−
Typ
250
−
Max
500
0.5
Unit
mA
mA
V
I
Internal Supply Current (R
(Note 13)) = 13kW, RX/RXI = mark)
CC
IDD
I
IO
Current drawn by the V pin
−0.5
1.15
IO
V
RIDD
Voltage on RIDD pin
1.2
1.25
12.All voltages are referenced to GND
13.Resistor with 1% accuracy
www.onsemi.com
5
NCN5151
Table 8. VDD REGULATOR ELECTRICAL CHARACTERISTICS (Note 14)
Symbol
Parameter
Min
3.1
Typ
3.3
−
Max
3.6
−
Unit
V
V
DD
Voltage on V (I < 15 mA)
DD DD
I
Peak current that can be supplied by V Note 15 with condition V
> 3.8 V
15
mA
mA
V
DD
DD
STC
I
V
BUS
= 0 V, V = 0 V
STC
−0.5
2.65
2.55
5.6
−
0.5
3.15
3.00
6.4
DD, OFF
V
Power−on reset threshold to connect V
2.85
2.75
6.0
POR, ON
DD
V
Power−on reset threshold to disconnect V
V
POR, OFF
DD
V
Threshold voltage on pin STC to turn on V
regulator and pull high PF pin.
PMODE high (VB > 10.6 V)
M−Bus Mode
V
STC,VDDON
DD
PMODE low (VB < 10.6 V)
Low Power Mode
3.1
2.7
3.4
3.0
3.6
3.2
V
V
V
Threshold voltage on pin STC to turn off V regulator and pull low PF pin
DD
STC,VDDOFF
14.All voltages are referenced to GND
15.Average current draw limited by I
STC
Table 9. M−BUS RECEIVER ELECTRICAL CHARACTERISTICS (Note 16)
Symbol Parameter
Min
Typ
Max
Mark − 5.7
Unit
V
T
Receiver threshold voltage
Mark −
8.2
V
V
SC
Mark level storage capacitor voltage
V
B
V
I
Mark level storage capacitor charge current
Mark level storage capacitor discharge current
−40
0.3
−25
0.6
−15
mA
mA
SC, charge
I
−0.033 x
SC, discharge
I
SC, charge
CDR
Charge/Discharge current ratio
30
40
−
−
V
V
TX/TXI high−level voltage (I /I
= −100 mA) (Note 17)
= 100 mA)
TX TXI
V
IO
−
V
IO
V
V
TX,OH1
TXI,OH1
TX TXI
0.6
V
TX/TXI low−level voltage (I /I
0
0.20
0.35
TXI,OL1
V
TX,OL1
V
TX/TXI low−level voltage (I
= 1.1 mA)
−
0
1
1.5
16
V
TX,OL2
TXI
I
, I
V
TX
= 7.5 V, V = 6 V
STC
11
mA
TX TXI
16.All voltages are referenced to GND
17.V > V + 1 V
STC
IO
Table 10. LOW POWER MODE RECEIVER ELECTRICAL CHARACTERISTICS (Note 18)
Symbol
Parameter
Receiver low threshold voltage (Falling V
Min
1.2
1.5
Typ
Max
Unit
V
V
TL,LP
)
BUS
1.6
2
2.4
2.7
V
TH,LP
Receiver high threshold voltage (Rising V
)
V
BUS
V
V
TX/TXI high−level output voltage (I /I
= −100 mA) with V
≥ V + 0.7 V
V
0.75
−
V
0.6
−
V
IO
V
TX,OH2
TXI,OH2
TX TXI
STC
IO
IO
IO
V
V
TX/TXI high−level output voltage (I /I
= −50 mA) with V
≥ V + 0.5 V
V
0.6
−
V
0.45
−
V
V
V
TX,OH3
TXI,OH3
TX TXI
STC
IO
IO
IO
IO
V
TX/TXI low−level output voltage (I /I
= 100 mA)
0
0.20
0.35
TXI,OL3
TX TXI
V
TX,OL3
18.All voltages are referenced to GND
www.onsemi.com
6
NCN5151
Table 11. M−BUS TRANSMITTER ELECTRICAL CHARACTERISTICS (Note 19)
Symbol
Parameter
Space level modulating current with R = 100 W (Note 20)
Min
12.5
1.2
Typ
15
Max
18
Unit
mA
V
I
MC
RIS
V
RIS
Voltage on RIS pin
1.4
1.6
5.5
V
, V
RXI,IH
RX/RXI high−level input voltage
V
IO
−
V
RX,IH
0.8
V
, V
RX/RXI low−level input voltage
0
6
0.8
30
V
RX,IL
RXI,IL
I
, I
Current drawn from RX/RXI pins (Note 21) (V = 3 V)
mA
RX RXI
IO
19.All voltages are referenced to GND
20.Resistor with 1% accuracy
21.Including internal pull−up resistor on RX and internal pull−down resistor on RXI
Table 12. LOW POWER MODE TRANSMITTER ELECTRICAL CHARACTERISTICS (Note 22)
Symbol
Parameter
Min
Typ
Max
Unit
2−WIRE LOW POWER MODE
I
Transmission current with R
= 100 W (Note 23)
RIS
8.5
10
11.5
1.15
mA
V
TX,2WLPM
V
Voltage on RIS pin
0.85
1.00
RIS,2WLPM
3−WIRE LOW POWER MODE
OD low−level output voltage, I = 2 mA
V
OD,OL
0
0
0.1
−
0.3
1
V
OD
I
OD leakage current, V = 10 V
mA
LEAK,OD
OD
22.All voltages are referenced to GND
23.Resistor with 1% accuracy
Table 13. VB MONITOR ELECTRICAL CHARACTERISTICS (Note 24)
Symbol
Parameter
VB voltage level to enable PMODE pin
Min
Typ
9.4
−
Max
Unit
V
V
8.0
10.5
VB,PMODE
V
PMODE high−level output voltage, I
= −50 mA
V
DD
−
V
DD
V
PMODE,OH
PMODE
0.3
V
PMODE low−level output voltage , I
= 50 mA
0
−
0.3
V
PMODE,OL
PMODE
24.All voltages are referenced to GND
Table 14. 2WLPM and 3WLPM INPUT CHARACTERISTICS (Note 25)
Symbol
Parameter
Min
Typ
Max
Unit
I
I
2WLPM / 3WLPM pull−down current, (voltage range: 0.2 to 3.3 V)
2
uA
2WLPM,IL
3WLPM,IL
V
V
2WLPM / 3WLPM low−level input voltage
2WLPM / 3WLPM high−level input voltage
0
−
−
0.2 x
VDD
V
V
2WLPM,IL
3WLPM,IL
V
V
0.8 x
VDD
VDD
2WLPM,IH
3WLPM,IH
25.All voltages are referenced to GND
Table 15. 2WLPM, 3WLPM, and OD TRUTH TABLE
2WLPM
3WLPM
Operating Mode
M−Bus
OD
L
L
L
HiZ
H
3 Wire Low Power Mode
Space (Note 26) state: Low
Mark (Note 27) state: HiZ
H
H
L
2 Wire Low Power Mode
Not Valid (Note 28)
High Impedance
H
Space state: Low
Mark state: HiZ
26.“Space” state means RX “0” or RXI “1”
27.“Mark” state means RX “1” or RXI “0”
28.Note 2WLPM and 3WLPM both High is not a valid combination. This state is not destructive for the NCN5151 device, but the communication
will fail
www.onsemi.com
7
NCN5151
APPLICATION SCHEMATICS − M−BUS APPLICATION ONLY
CVDD
VIO
VDD
16
13
PMODE
2WLPM
3WLPM
PF
5
10
15
8
OD
19
RBUS1
BUSL1
VB
NCN5151
2
4
3
TX
12
11
17
18
mC
TXI
RX
TVS1
M−BUS
RXI
BUSL2
20
9
1
7
6
RBUS2
RIS
SC
GND RIDD STC
RIDD CSTC
CSC
R
IS
PC20130419.4
Figure 3. General Application Schematic
CVDD
VIO
VDD
16
13
PMODE
2WLPM
3WLPM
PF
5
10
15
8
OD
19
RBUS1
BUSL1
VB
NCN5151
2
4
3
TX
12
11
17
18
mC
TXI
RX
TVS
1
M−BUS
RXI
BUSL2
20
9
1
7
6
RBUS2
RIS
SC
GND RIDD STC
CSTC
CSC
R
R
IS
IDD
PC2010419.5
Figure 4. Application Schematic with External Power Supply
www.onsemi.com
8
NCN5151
VBB
VDD
CVDD
VIO
13
VDD
16
PMODE
VSTC
5
2WLPM
3WLPM
PF
10
15
8
OD
19
RBUS1
BUSL1
VB
NCN5151
2
4
3
TX
12
11
VDD
VBB
TXI
RX
TVS
1
M−BUS
mC
17
18
RXI
20
9
1
7
6
RBUS2
BUSL2
RIS
SC
GND RIDD STC
VSTC
CSC
R
CSTC
IDD
R
IS
PC20130419.6
Figure 5. Optically Isolated Application Schematic
Table 16. TYPICAL BILL OF MATERIALS − M−BUS MODE
Reference Designator
Value (Typical)
Tolerance
Manufacturer
ON Semiconductor
ON Semiconductor
Part Number
U
NCN5151
1
TVS
C
40 V
1SMA40CAT3G
1
≥1 mF
−20%,
+80%
VDD
R
100W
1%
IS
C
220 nF
−20%,
+80%
SC
R
, R
220 W
30 kW
10%
1%
BUS1
BUS2
R
1 UL
2 UL
IDD
13 kW
1%
3 UL (Note 29)
4 UL (Note 29)
5 UL (Note 29)
6 UL (Note 29)
1 UL
8.45 kW
6.19 kW
4.87 kW
4.02 kW
<330 mF
<680 mF
<1000 mF
<1500 mF
<2200 mF
<2200 mF
1%
1%
1%
1%
C
10%
10%
10%
10%
10%
10%
STC
2 UL
3 UL (Note 29)
4 UL (Note 29)
5 UL (Note 29)
6 UL (Note 29)
29.3−6 UL configurations are only possible for the NQFP variant.
www.onsemi.com
9
NCN5151
APPLICATION INFORMATION − M−BUS MODE
This section provides some information related to M−bus
mode application.
1.5 mA called unit loads. Table 5 lists the different values of
programming resistors needed for different unit loads, as
The NCN5151 is a slave transceiver for use in the M−Bus
protocol. The bus connection is fully polarity independent.
The transceiver will translate the bus voltage modulation
from master−to−slave communication to TTL UART
communication, and in the other direction translate UART
voltage levels to bus current modulation. The transceiver
also integrates a voltage regulator for utilizing the current
drawn in this way from the bus, and an early power fail
warning. The transceiver also supports an external power
supply and the I/O high level can be set to match the slave
sensor circuit. A complete block diagram is shown in
Figure 2. Each section will be explained in more detail
below.
well as the current drawn from the bus (I
) and the current
BUS
that can be drawn from the STC pin (I ). I
is slightly
STC STC
less than I
to account for the internal power consumption
BUS
of the NCN5151.
The resistors R
used must be at least 1% accurate. Note
IDD
that using 5 and 6 Unit Loads is not covered by the M−BUS
standard.
When the voltage on the STC pin reaches V
the LDO is turned on, and will regulate the voltage on the
VDD pin to 3.3 V, drawing current from the storage
capacitor. A decoupling capacitor of minimum 1 mF is
required on the VDD pin for stability of the regulator. On the
STC pin, a minimum capacitance of 10 mF is required.
STC,VDDON
Furthermore, the ratio C /C
The voltage on the STC pin is clamped to V
must be larger than 9.
STC VDD
M−Bus Protocol
by a shunt
STC
M−BUS is a European standard for communication and
powering of utility meters and other sensors.
Communication from master to slave is achieved by
voltage−level signaling. The master will apply a nominal
+36 V to the bus in idle state, or when transmitting a logical
1 (“mark”). When transmitting a logical 0 (“space”), the
master will drop the bus voltage to a nominal +24 V.
Communication from the slave to the master is achieved by
current modulation. In idle mode or when transmitting a
logical 1 (“mark”), the slave will draw a fixed current from
the bus. When transmitting a logical 0 (“space”), the slave
will draw an extra nominal 15 mA from the bus. M−BUS
uses a half−duplex 11−bit UART frame format, with 1 start
bit, 8 data bits, 1 even parity bit and a stop bit.
Communication speeds allowed by the M−BUS standard are
300, 600, 2400, 4800, 9600, 19200 and 38400 baud, all of
which are supported by the NCN5151.
regulator which will dissipate any excess current that is not
used by the NCN5151 or external circuits.
Slave Power Supply (External Battery)
In case the external sensor circuit consumes more than the
allowed bus current or the sensor should be kept operational
when the bus is not present, an external power supply, such
as a battery, is required (Figure 4).
When the external circuitry uses different logical voltage
levels, simply connect the power supply of that voltage level
to VIO, so that the RX, RXI, TX, TXI and PF pins will
respond to the correct voltage levels. The NCN5151 will still
be powered from the bus, but all communication will be
translated to the voltage level of VIO.
Contrary to the NCN5150, the NCN5151 does not support
the remote supply/Battery support because of the
V
level which has been lowered below 3.3 V for
STC,VDDOFF
low bus voltage operation.
Bus Connection and Rectification
The bus should be connected to the pins BUSL1 and
BUSL2 through series resistors to limit the current drawn
from the bus in case of failure (according to the M−BUS
standard). Typically, two 220 W resistors are used for this
purpose.
Communication, Master to Slave
M−BUS communication from master to slave is based on
voltage level signaling. To differentiate between master
signaling and voltage drop caused by the signaling of
another slave over cabling resistance, etc., the mark level
Since the M−BUS connection is polarity independent, the
NCN5151 will first rectify the bus voltage through a
semi−active bridge rectifier.
V
is stored, and only when the bus voltage drops to
MARK
less than V will the NCN5151 detect communication. A
T
simplified schematic of the receiver is shown in Figure 7.
The received data is transmitted on the pins TX and TXI, as
shown in the waveforms in Figure 6.
An external capacitor must be connected to the SC pin to
store the mark voltage level. This capacitor is charged to V .
Discharging of this capacitor is typically 40x slower, so
that the voltage on SC drops only a little during the time the
master is transmitting a space. The value of C must be
Slave Power Supply (Bus Powered)
A slave device can be powered by the M−BUS or from an
external supply. The M−BUS standard requires the slave to
draw a fixed current from the bus. This is accomplished by
the constant current source CS1. This current is used to
S
charge the external storage capacitor C . The current
STC
SC
drawn from the bus is defined by the programming resistor
chosen in the range of 100 nF − 330 nF.
R
IDD
. The bus current can be chosen in increments of
www.onsemi.com
10
NCN5151
V
V
RX
BUS
V
V
MARK
IO
V
0
T
V
T
= 21 … 42 V
MARK
V
V
= V
− 6 V
MARK
MARK
= V
V
SPACE
− 12 V
I
SPACE
BUS
I
I
I
= I
+ 15 mA
SPACE
SPACE
MARK
V
TX
V
IO
= N unit loads
MARK
I
MARK
0
PC20130514.5
V
TXI
V
Figure 8. Slave to Master Communication Driving RX
IO
V
RX
0
V
IO
PC20130419.1
0
Figure 6. Master to Slave Communication
I
BUS
CSC
I
SPACE
I
I
= I
+ 15 mA
SPACE
MARK
PC20130516.2
SC
= N unit loads
I
MARK
MARK
9
VB_INT
NCN5151
PC20130514.6
VIO_BUF
ICHARGE
Figure 9. Slave to Master Communication Driving RXI
12
11
TX
A
B
Encoding
IDISCHARGE
A: M−Bus Mode
B: 2&3Wire LPM
TXI
VIO_BUF
17
LP_CTL
ECHO
Figure 7. Receiver Block
ECHO
LP_TX
LP_CTL
VB_IN
RX
A: M−Bus/2WLP Mode
B: 3−Wire LP Mode
B
Decoding
18
Communication, Slave to Master
RXI
A
M−BUS communication from slave to master uses bus
current level modulation while the voltage remains constant.
This current modulation can be controlled from either the
RX or RXI pin as shown in Figures 8 and 9. When
transmitting a space (“0”), the current modulator will draw
an additional current from the bus. This current can be set
CS_TX
M−Bus: 1.5V
2−Wire LP: 1V
with a programming resistor R . To achieve the space
RIS
current required the M−BUS standard, R
should be
RIS
100 W. A simplified schematic of the transmitter is shown in
Figure 10.
NCN5151
20
RIS
PC20130516.1
RIS
Because the M−BUS protocol is specified as half−duplex,
an echo function will cause the transmitted signal on RX or
RXI to appear on the receiver outputs TX and TXI. Should
the master attempt to send at the same time, the bitwise
added signal of both sources will appear on these pins,
resulting in invalid data.
Figure 10. Transmitter Block
www.onsemi.com
11
NCN5151
200
150
100
50
be used to dimension the value of the bulk C
taking into account that the M−BUS standard requires t to
be less than 3 s.
For certain applications where the power drawn from the
bus is not used in external circuits, the storage capacitor
value can be much lower. The NCN5151 requires a
needed,
STC
on
minimum STC capacitance of 10 mF (and C /C
> 9)
STC VDD
to ensure that the bus current regulation is stable under all
conditions.
V
BUS
V
= V
STC
+ 0.6
B
V
B,min
5
10
15
20
25
I
(mA)
MC
V
STC
Figure 11. Typical Modulation Current and RIS
Resistor
V
STC,CLAMP
V
STC,VDD ON
V
STC,VDD OFF
0
Power On/Off Sequence and Power Fail Indicator
The power-on and power-off sequence of the NCN5150
is shown in Figure 12. Shown also in Figure 12 is the
operation of the PF pin. This pin is used to give an early
warning to the microcontroller that the bus power is
collapsing, allowing the microcontroller to save its data and
t
t
OFF
ON
V
DD
0
V
PF
V
IO
shut down gracefully. The times t and t can be
on
off
approximated by the following formulas:
0
PC20130419.3
CSTC
Figure 12. Power−on and Power−off
ton
+
VSTC,VDDON
ISTC
CSTC
Thermal Shutdown
ǒ
Ǔ
toff
+
VSTC,CLAMP * VSTC,VDDOFF
IDD ) ISTC
The NCN5151 includes a thermal shutdown function
disabling the transmitter in case of excessive junction
temperature.
Where I
is the internal current consumption of the
CC
NCN5151 and I
is the current consumed by external
DD
circuits drawn from either VDD or STC. These formulas can
www.onsemi.com
12
NCN5151
APPLICATION SCHEMATICS
LOW−POWER MODE and M−BUS APPLICATIONS
CVDD
VOD
PF
VOD
VIO
VDD
16
13
8
RF−MODULE
PMODE
2WLPM
ROD
5
OD
19
Data IN
“0”
“1”
10
15
12
11
TVS
1
3WLPM
Sensor
System
RBUS1LP
BUSL1
VB
NCN5151
2
4
3
TX
TXI
DC
Supply
+
TVS
D1
2
RX
17
18
D2
ON/OFF
Keying
TVS3
RXI
BUSL2
20
9
1
7
6
RBUS2LP
RIS
SC
GND RIDD STC
RIDD CSTC
CSC
BAT_RF
RIS
Min: 4.75 V
Max: 9 V
4.75 .. 9 V
0 V
PC20130419.9
Figure 13. 3−Wire Low Power Mode and M−Bus Application Schematic
4.75 .. 9 V
C
VDD
V
V
OD
OD
PF
0 V
VIO
VDD
13
16
8
MODULE
PMODE
2WLPM
R
OD
5
OD
19
“1”
“0”
10
15
12
11
TVS
TVS
1
2
3WLPM
TX
Sensor
System
R
BUS1LP
BUSL1
VB
NCN5151
2
4
DC
Supply
+
D
1
TXI
RX
17
18
D
R
2
ON/OFF
Keying
TVS
3
RXI
3
6
BUSL2
20
9
1
7
BUS2LP
RIS
SC
GND RIDD
STC
BAT
C
SC
R
C
IDD
R
STC
IS
Min: 4,75 V
Max: 9 V
PC20130419.7
Figure 14. 2−Wire Low Power Mode and M−Bus Application Schematic
www.onsemi.com
13
NCN5151
Table 17. TYPICAL BILL OF MATERIALS − LOW POWER MODE
Reference
Designator
Value
(Typical)
Tolerance
Manufacturer
Part Number
NCN5151
Note
U
ON Semiconductor
ON Semiconductor
ON Semiconductor
ON Semiconductor
1
TVS
TVS
40 V
30 V
1SMA40AT3G
1SMA30AT3G
BAS70LT1G
1
2
D1, D2
Absolute maximum reverse
voltage >40 V
C
≥1 mF
100 W
220 nF
33 W
−20%, +80%
1%
VDD
R
IS
C
−20%, +80%
SC
R
R
,
Murata
PRG18B330MB1RB
Over−current protection resistor
type are recommended for Low
Power Modes
BUS1LP
BUS2LP
R
560 W
30 kW
10%
1%
OD
R
C
1 U
2 U
1 U
2 U
IDD
L
L
L
L
13 kW
1%
<330 mF
<680 mF
10%
10%
Min : 22 mF with C
/ C
> 9
STC
STC
VDD
APPLICATION INFORMATION − LOW POWER MODE
3−Wire LP Mode − RF Module − Bidirectional
This section provides some information related to the
NCN5151 operating in Low Power mode. As depicted in
Figure 13, the NCN5151 also offers the possibility to build
an extremely low power communication with an external RF
Module.
between 4.75 and 9 V; two 3 V lithium batteries are normally
used in a system like this.
Figure 17 illustrates this bidirectional communication in
3−wire LP mode.
The OD pin has to be protected against surge transients
with a TVS and a series resistor R . This resistor acts also
OD
This topology uses a 3−wire interface: the regular bus
lines (BUSL1, BUSL2) and the open drain pin (OD).
This three−wire interface is designed in such a way that
when the system is switched on, the Sensor System detects
as a current limiter in case of a short between the 9V battery
module and the wire “Data_In” going to the OD connector,
while 3WLPM and RX/RXI are active. The current through
the OD pin is limited to 20 mA. Therefore a typical R
OD
via the third contact V whether any direct connection with
resistor of 560 W is recommended. (Note that the internal
OD switch has a typical R of 50 W)
OD
the external battery module exists. If this is the case, the
Sensor System enables the 3WLPM (three−wire low power
mode) pin. The low power logic changes the operating mode
of the transmitter block (Figures 2 and 10). The
communication from slave to RF module does not take place
via energy−intensive current modulation, but instead by
means of a purely digital signal on the OD pin. This enables
extremely energy−saving communication with the master.
As with the M−Bus, the RF module signals the data to the
NCN5151 through voltage modulation but in this case this
is purely ON/OFF keying. This means the power supply
(maximum of 9 V) is simply switched on and off. As
illustrated in Figure 7 the receiver threshold switches to a
level referenced to ground instead of the mark state. The
sensor system has to make sure that it has sufficient energy
to send data and save enough energy in a capacitor for this
purpose. During communication from the RF module to the
sensor, the sensor system must also have sufficient energy
and buffer this if necessary. The power supply can be
DS(on)
2−Wire LP Mode − SCR − Bidirectional
The second low power mode works with a 2−wire
interface also called SCR (System for meter
Communication and Readout for powerless meters) which
is enabled with the 2WLPM input pin (see Figure 14).
The communication from master to slave is done with
ON/OFF keying similar to 3−wire LP mode, but the
communication from slave to master uses current
modulation similar to the current modulation used in the
M−Bus protocol. In order to handle the low supply voltage
(down to 4.75 V) and limit voltage losses, the current
modulation amplitude is reduced with 33% (10 mA vs
15 mA) as illustrated in Figure 10.
Figure 18 illustrates the bidirectional communication in
2−wire LP mode.
Precautions regarding the stored energy during ON/OFF
keying are also valid for this mode
www.onsemi.com
14
NCN5151
MBUS and Low Power Mode Recognition
This current limit in low power mode is double compared
to the M−BUS mode (Table 6, Figures 15 and 16). This
The NCN5151 includes a VB voltage monitor with an
output pin PMODE (Power Mode) indicating whether VB
voltage is above 9.5 V typical. This information is sent to the
sensor system which determines the relevant mode (using
the OD state pin): M−Bus, 2−wire or 3−wire low power
mode. The sensor system then signals the NCN5151 the
chosen operating mode using 2WLPM and 3WLPM pins
(see Figures 15 and 16). During 2WLPM or 3WLPM the PF
output is disabled and pulled to ground.
By keeping the selection mode mechanism outside the
NCN5151, the user can enhance the meter application
robustness and its reliability through the sensor system
firmware based on their application environment.
allows a faster recharge of C
a duty cycle close to 50%.
during ON/OFF keying and
STC
Low Power Mode and Minimum Operating Voltage
The user should take several precautions when using the
low power modes in order to maximize the voltage seen by
the NCN5151 circuitry.
It is required to replace the 220 W bus resistors with
current limiting resistor (33 W typ, PTC type with rapid
operation). This will significantly reduce the voltage drop,
especially during current modulation (slave to master) in
2WLPM and guarantee sufficient short protection.
An external Schottky (with forward voltage of 0.3 V max)
is also required between BUSL1/BUSL2 and the VB pin in
order to reduce the overall voltage drop on the internal diode
bridge.
Table 15 gives an overview of the low power pin truth
table. Note that both 2WLPM and 3WLPM pins enabled is
not allowed. This combination is safe for the NCN5151 but
the communication with the master may fail.
These adaptations allow the NCN5151 to operate in low
power mode with a minimum battery voltage of 4.75 V.
As mentioned in both low power mode sections, it is
important to maintain a minimum voltage level on the STC
pin during the ON/OFF keying. Below 3.8 V on STC, the
low dropout regulator may not be able to regulate the VDD
supply pin correctly.
CS1 Current Source and STC Clamp
Contrary to M−BUS mode, in low power mode the
NCN5151 does not behave as a constant current load. The
STC clamp level (V ) is increased higher than
STC,CLAMP,LP
the low power mode supply (9.5 V typical) in order to never
trigger it under normal operating range. Thus the CS1 will
only act as current limiter during startup and ON/OFF
keying and in steady state the CS1 block will be pinched off
between STC and VB.
www.onsemi.com
15
NCN5151
V
VBUS
5 V
VSTC
VSTC,VDDON
VPOR,ON
VDD
1
1
2
V
release
DD
0
Drop of I
due to clamping of STC to V
BUS
IBUS
BUS
IBUS_MAX= 2 x f(RIDD
)
3
4
Detection and enabling 3−wire low power
mode by the external mC/sensor
2
Increases of bus current limit (x2) and
increase of STC clamp level
IBUS_MAX= f(RIDD
)
ICC + ISENSOR
0
VOD
4
0
VPMODE
0
V2WLPM
0
V3WLPM
3
0.8 V
DD
0
VTX
V
IO
0
VTXI
0
PC20130514.1
Figure 15. Startup Sequence in 3−Wire Low Power Mode
www.onsemi.com
16
NCN5151
V
VBUS
5 V
VSTC
VSTC,VDDON
VPOR,ON
VDD
1
1
2
V
release
DD
0
Drop of I
due to clamping of STC to V
BUS
IBUS
BUS
IBUS_MAX = 2 x f(RIDD
)
Detection and enabling 2−wire low power
mode by the external mC/sensor
3
4
2
Increases of bus current limit (x2) and
increase of STC clamp level
IBUS_MAX = f(RIDD
)
ICC + ISENSOR
0
VOD
4
0
VPMODE
0
V2WLPM
0.8 VDD
0
V3WLPM
3
0
VTX
V
IO
0
VTXI
0
PC20130514.2
Figure 16. Startup Sequence in 2−Wire Low Power Mode
www.onsemi.com
17
NCN5151
Master to Slave
Slave to Master
V
VBUS
VSTC
VTH,LP
VTL,LP
0
IBUS
IBUS_MAX= 2 x f(R
)
IDD
ICC + ISENSOR
0
VOD
V
IO
0
VRX
VDD
0
VTX
V
IO
0
VTXI
V
IO
0
V2WLPM
VDD
0
V3WLPM
VDD
PC20130514.3
0
Figure 17. Communication in 3−wire Low Power Mode
www.onsemi.com
18
NCN5151
Master to Slave
Slave to Master
V
VBUS
VSTC
VTH,LP
VTL,LP
0
IBUS
ITX,2WLPM
IBUS_MAX= 2xf(R
)
IDD
ICC
+
ISENSOR
0
VOD
V
IO
0
VRX
V
IO
0
VTX
V
IO
0
VTXI
V
IO
0
V2WLPM
VDD
0
V3WLPM
VDD
0
PC20130514.4
Figure 18. Communication in 2−wire Low Power Mode
Table 18. ORDERING INFORMATION
†
Device
Package
Shipping
2500 / Tape & Reel
NCN5151MNTWG
NQFP20, 4x4
(Pb-free)
†For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging
Specifications Brochure, BRD8011/D.
www.onsemi.com
19
NCN5151
PACKAGE DIMENSIONS
QFN20, 4x4, 0.5P
CASE 485E
ISSUE B
NOTES:
1. DIMENSIONING AND TOLERANCING PER ASME
Y14.5M, 1994.
2. CONTROLLING DIMENSION: MILLIMETERS.
3. DIMENSION b APPLIES TO PLATED TERMINAL
AND IS MEASURED BETWEEN 0.15 AND 0.30 MM
FROM THE TERMINAL TIP.
A
B
D
A3
EXPOSED Cu
MOLD CMPD
PIN ONE
REFERENCE
4. COPLANARITY APPLIES TO THE EXPOSED PAD
AS WELL AS THE TERMINALS.
E
A1
2X
MILLIMETERS
DETAIL B
OPTIONAL CONSTRUCTIONS
DIM MIN
MAX
1.00
0.05
0.15
C
A
A1
A3
b
0.80
---
2X
0.20 REF
0.15
C
0.20
0.30
L
L
TOP VIEW
D
4.00 BSC
D2
E
2.60
2.60
2.90
4.00 BSC
(A3)
DETAIL B
L1
A
E2
e
2.90
0.10
C
0.50 BSC
0.20 REF
K
DETAIL A
OPTIONAL CONSTRUCTIONS
L
0.35
0.00
0.45
0.15
0.08
C
L1
SEATING
PLANE
A1
C
SIDE VIEW
SOLDERING FOOTPRINT*
0.10 C A B
4.30
20X
D2
DETAIL A
0.58
20X L
6
2.88
0.10 C A B
11
E2
1
1
2.88
4.30
20
K
20X b
e
0.10 C A B
0.05
C
NOTE 3
PKG
OUTLINE
BOTTOM VIEW
20X
0.35
0.50
PITCH
DIMENSIONS: MILLIMETERS
*For additional information on our Pb-free strategy and soldering
details, please download the ON Semiconductor Soldering and
Mounting Techniques Reference Manual, SOLDERRM/D.
ON Semiconductor and
are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC owns the rights to a number of patents, trademarks,
copyrights, trade secrets, and other intellectual property. A listing of SCILLC’s product/patent coverage may be accessed at www.onsemi.com/site/pdf/Patent−Marking.pdf. SCILLC
reserves the right to make changes without further notice to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any
particular purpose, nor does SCILLC assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without
limitation special, consequential or incidental damages. “Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications
and actual performance may vary over time. All operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. SCILLC
does not convey any license under its patent rights nor the rights of others. SCILLC products are not designed, intended, or authorized for use as components in systems intended for
surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where
personal injury or death may occur. Should Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and
its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly,
any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was negligent regarding the design or manufacture
of the part. SCILLC is an Equal Opportunity/Affirmative Action Employer. This literature is subject to all applicable copyright laws and is not for resale in any manner.
PUBLICATION ORDERING INFORMATION
LITERATURE FULFILLMENT:
N. American Technical Support: 800−282−9855 Toll Free
USA/Canada
Europe, Middle East and Africa Technical Support:
Phone: 421 33 790 2910
Japan Customer Focus Center
Phone: 81−3−5817−1050
ON Semiconductor Website: www.onsemi.com
Order Literature: http://www.onsemi.com/orderlit
Literature Distribution Center for ON Semiconductor
P.O. Box 5163, Denver, Colorado 80217 USA
Phone: 303−675−2175 or 800−344−3860 Toll Free USA/Canada
Fax: 303−675−2176 or 800−344−3867 Toll Free USA/Canada
Email: orderlit@onsemi.com
For additional information, please contact your local
Sales Representative
NCN5151/D
相关型号：
©2020 ICPDF网 联系我们和版权申明