Transcript
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IsoLoop Isolation Products Illustrative Applications
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Isolated Isolated Isolated Isolated Isolated
RS-485/PROFIBUS CANbus ADCs and DACs Serial Interfaces Power Interfaces
Isolated RS-485/PROFIBUS Single-Chip RS-485/PROFIBUS Isolated Transceivers NVE offers the industry’s broadest line of single-chip isolated RS-485 transceivers, including digital and passive input versions, fractional-load versions, and PROFIBUS-compliant versions. Termination resistors can be added to maximize speed and transmission length. Fail-safe resistors guarantee a known state on a terminated bus with no active transceivers. NVE transceivers are available with data rates are up to 40 Mbps. Parts are available in 0.3" and 0.15" 16-pin SOIC packages.
5V
5V
DE
DE V D
IL3585
R B RE
RFS
390R
RE
RT
B
A
110R
R
D RT
110R
A
RFS
390R
D
IL3585
IsoLoop logic isolators can also be used as part of multi-chip designs to isolate signals using particular non-isolated transceivers (see examples below).
V DD1
8
R
Single-Component RS-485 Receiver Using IL610 An IL610 can be used as a simple isolated RS-485/RS-422 receiver. No external resistors are required, and cabling is greatly simplified by eliminating the need to power the input side of the receiving board. The circuit is failsafe because the IL610 is guaranteed to switch to the high state when the coil input current is less than 500 µA. No current-limiting resistor is needed for a single receiver because it will draw less current than the driver maximum. There is also no need for line termination resistors in most IL610 line receiver applications below a data rate of about 10 Mbps because the IL610 coil resistance of approximately 70 Ohms is close to the characteristic impedance of most cables.
V DD2
ISL8485
1
47nF
8
IL610
B 7
D
3
4 2
6
+
RE
7 6
47nF
R
5
A
5
GND1
A unique IL610 MSOP is available for space-critical boards.
GND2
VDD1
VDD2
8
C1
Isolated Fractional Load RS-485 Using IL614 NVE offers a broad line of single-chip isolated RS-485 transceivers, but the unique IL614 threechannel isolator can also be used as part of a multichip design with non-isolated transceivers. The IL614 provides 2.5 kVRMS isolation (1 minute) and 20 kV/µs transient immunity. The IL614-3 is in a narrow-body (0.15"-wide) package when board space is critical.
R Cboost
DE
ISL8487E
1 2 3 4
+ RE
16 15 14
Cboost
C3 390R
1
R 7
1K
5
+ -
13
+
11
12
6 Cboost
D 1K
7 8
C2
2
RE
3
DE
4
D
10 9
IL614
B
220R
6
A 390R
5
GND1
GND2
Isolated Controller Area Network
Isolating Standard CAN Transceivers Isolating CAN allows higher bus speed and more reliable operation by eliminating ground loops and reducing susceptibility to noise and EMI. This simple circuit works with any CAN transceiver with a TxD dominant timeout, which includes all of the current-generation transceivers, such as the ubiquitous Philips/NXP TJA1050.
3
ADR 0...7, CS
Tx0
TxD
1
XTAL1
Rx0
RxD
4
7
CANH
6
CANL
XTAL2 IL712/IL721
TJA1050
2
SJA1000
The IL700’s best-in-class propagation delay of 10 ns minimizes CAN loop delay and maximizes data rate over any given bus length.
+5V
Bus 50K 0.1µF
SN74F02 1µF
RST TX
2 3
1
5 6
8 9
RX
SJA1000
4
10
12 11
13
1
8
2
7
3
6
4
5
IL712
CANH
TXD RXD
CANL
PCA 82C250
Isolating Legacy CAN Transceivers Power-on reset circuitry allows an IL712 to isolate legacy transceivers that lack integrated TxD timeout, such as the Philips/NXP PCA82C250.
Isolated A/D and D/A Converters Bridge Bias
Sampling A/D
Delta Sigma A/D
ADS8513
CS5532
Bridge Bias
Delta Sigma A/D CS5532 Isolation Boundary
Isolation Boundary
Analog Ch 1
Channel 1
Serial Data Out
Bridge + Bridge -
Iso SD Out
Serial Data In
Iso DS In
Data Clock
Iso Data Clo
Chip Select
Iso SD Out
SD Out
Iso SD Out
SD Out
Iso SD In
SD In
Iso Busy 1
Busy 1
Iso Data Clock
Data Clock
Iso Data Clock
Data Clock
Iso CS
CS
Iso CS 1
CS1
Iso SD In
SD In
Iso CS OSC 1
IL262
IL261
Sampling A/D
IL717 Bridge Bias
Delta Sigma A/D
ADS8513 Clock Generator
CS5532
Analog Ch 2
Single-Channel Isolated SPI Delta-Sigma A/D Converter Using IL717 This circuit illustrates a typical single-channel delta-sigma isolated ADC SPI interface. The A/D is located on the bridge with no signal conditioning electronics between the bridge sensor and the ADC. In this case, the IL717 is the best choice for isolation. It isolates the control bus from the microcontroller. The system clock is located on the isolated side of the system.
Channel n Iso SD Out
SD Out
Iso SD In
SD In
Iso Data Clock
Data Clock
Iso CS
CS
Iso SD Out
SD Out
Iso Busy 2
Busy 2
Iso Data Clock
Data Clock
Iso CS2
CS2
Iso SD In
SD In IL262
OSC n
IL261
Multi-Channel Isolated Delta-Sigma A/D Converter Using IL261s This circuit illustrates multiple ADCs configured in a channel-tochannel isolation configuration. The problem for designers is how to control clock jitter and edge placement accuracy of the system clock for each ADC. The best solution is to use a single clock on the system side and distribute this to each ADC. The IL261 adds a fifth channel to the IL717. This fifth channel is used to distribute a single, isolated clock to multiple ADCs.
Isolated Multi-Channel A/D Sampling With IL262s A multi-channel sampling system with separate A/D cells. The IL262 is used to control the SPI lines and send back ADC BUSY commands to the host, allowing efficient interruptdriven sampling. The BUSY line may also be used as a Frame Synchronization signal in video applications.
Isolation Boundary
Sampling ADC
Analog Power Supply
Digital Power Supply
ADS7825 Analog Ch 0
Multi-Channel Isolated Sampling A/D Converter Using IL261 The IL261 is ideal for isolating multi-channel sampling ADCs. Isolated channels A0 and A1 control the analog channel being sampled, while the three remaining I/O lines on the IL261 isolate the SPI interface.
Audio DAC IL260
Analog Ch 1 Analog Ch 2
Isolation Boundary
Analog Ch 3 Serial Data Out
Iso SD Out
R/C
Iso Read/Conv
Data Clock
Iso Data Clock
Channel A0
Iso Ch A0
Channel A1
Iso Ch A1 IL261
Isolated Audio DAC Using Two IL260s Isolation ensures the best DAC performance by eliminating much of the digital noise that tends to find its way onto the analog output. The unique five-channel IL260 isolator series allows ten channels of isolation with just two narrow-body or wide-body ICs.
MC
IMC
MS
IMS
PCM1681 L R
MD
IMD
SCK
ISCK
LF
LRCK
ILRCK
RF
BCK
IBCK
DATA1
IDATA1
RS
DATA2
IDATA2
CEN
DATA3
IDATA3
DATA4
IDATA4 IL260
LS
SUB
Isolated Serial Interfaces V DD1
V DD2 1
ISL8490
RS-422 Receiver Using IL610 An IL610 can be used as a simple isolated RS-422 receiver. Cabling is greatly simplified by eliminating the need to power the input side of the receiving board. A similar circuit can be used for RS-485 networks.
C1
8
IL610 6
D
Z
3
3
R 5
Y
2
7
+
6
RE C2
The IL610 provides 2500 VRMS isolation (one minute), and 20 kV/µs transient immunity. The IL610-1 is a unique MSOP isolator for space-critical boards.
R
5 Cboost
4
Notes: Cboost is application specific All other capacitors are 47 nF ceramic
GND1
GND2
5V
5V 2K2
Isolated I²C Using IL612A This circuit provides bidirectional isolation of I²C bus signals with no restrictions on data rate and none of the I²C bus latch-up problems common with other isolation circuits.
10K
750R
½ P82B96 8
SDA
1
270 pF
3 750R
2
C3
1 3
VDD2
C2 4
2 4
SDA_iso
7 8
VDD1
5 6
16 pF
750R
IL612A C1
GND1
GND2
Notes: C1, C2, and C3 are 47nF ceramic Resistor values change for 3 V operation
V DD1
V DD2 16
1 0.1 µF
IL712
0.1 µF
0.1 µF
3 4
V+
5
V-
2
6 0.1 µF
TD
T1OUT 14
11 T1 IN C3
RD
12
1
R1OUT
R1IN
C1
6
13
RD RTS TD CTS
RTS C4
10 T2 IN 9
CTS
T2 OUT
R2IN
C2
IL712 HIN232A 15
Note: C1 to C4 are 47 nF ceramic
9
7 5
R2OUT
8
Isolated RS-232 Using IL712s IL712s provide 2500 VRMS isolation (one minute) and 30 kV/µs typical commonmode transient immunity. The IL712-1 is a unique eight-pin MSOP dual-channel isolator to shrink board space.
Isolated Power Interfaces +5 V RL V1 3 Sensor 1
1K
8
IL610A
2
C1 6
+
Multi-channel Isolated Alarm Monitor Using IL610As IL600A-Series Isolators’ open-drain outputs can be wire-OR connected. Inputs can be configured for inverting or non-inverting operation, and a very wide input voltage range is possible. This illustrative circuit using IL610As to provide a fail-safe output (logic high output for zero coil current), 2500 VRMS isolation, and 20 kV/µs transient immunity. Typical logic output sink current is 10 mA for each isolator. Unlike optocouplers, IsoLoop Isolators do not degrade over time and have unlimited life.
5
Cboost
V2 3 Sensor 2
1K
2
System Error
8
IL610A
C2 6
+
5
Cboost
V3 3 Sensor 3
1K
8
IL610A
2
C3 6
+
5
Cboost
Notes: Cboost is application specific All other capacitors are 47 nF ceramic
GND1 +5 V
10-20 V 2
600 V max..
LM309H 1
3
Isolated Power Control Using IL610s The fail-safe output (logic high output for zero coil current) of IL610 Isolators ensures the power FETs will be off on power-up. The IL610 inputs can be configured for inverting or noninverting operation (see the IL600 Product Data Sheet). IL600-Series Isolators provide 2500 VRMS isolation (one minute), and 20 kV/µs transient immunity.
IL610
8 1 C1
3 Hi-Drive
1K
+
2
2 5
IL610
8
2
HIN
HO
LIN
VS
CAPP
3
7
6 To Load
C2
3 1K
VB 8
6
C boost
Lo-Drive
IR2102 VCC
+
6 5
4
COM
LO
5
C boost
GND1
GND2
Notes: Cboost is 16 pF CAPP is application specific All other capacitors are 47 nF ceramic
D
10 Vdc
G
MOSFET2
S
D
D
S
S
MOSFET3 MOSFET1 G
Microcontroller
IL511/IL611/IL711
G
Intelligent DC-DC Converter With Synchronous Rectification A typical primary-side controller uses a IL511, IL611 or IL711 isolator to drive the synchronous rectification signals from primary side to secondary side. IsoLoop pulse-width distortion as low as 0.3 ns typical minimizes MOSFET dead time and maximizes system efficiency. Ultra-small isolator packages (including two-channel MSOP-8s), allow the designer to squeeze more into less board area.
Visit www.IsoLoop.com NVE’s Website has more illustrative IsoLoop Isolator applications. NVE customers are constantly finding new, innovative applications for these remarkable devices.
About NVE An ISO 9001 Certified Company NVE Corporation manufactures innovative products based on unique spintronic Giant Magnetoresistive (GMR) technology. Products include Magnetic Field Sensors, Magnetic Field Gradient Sensors (Gradiometers), Digital Magnetic Field Sensors, Digital Signal Isolators, and Isolated Bus Transceivers. NVE pioneered spintronics and in 1994 introduced the world’s first products using GMR material, a line of ultra-precise magnetic sensors for position, magnetic media, gear speed and current sensing. NVE Corporation 11409 Valley View Road Eden Prairie, MN 55344-3617 USA Telephone: (952) 829-9217 Fax: (952) 829-9189 Internet: www.nve.com e-mail:
[email protected]
Worldwide Distribution NVE has a worldwide network of expert distributors ready to assist you. Visit the “Isolator Sales” section of www.nve.com for the nearest distributor.
The information provided by NVE Corporation is believed to be accurate. However, no responsibility is assumed by NVE Corporation for its use, nor for any infringement of patents, nor rights or licenses granted to third parties, which may result from its use. No license is granted by implication, or otherwise, under any patent or patent rights of NVE Corporation. NVE Corporation does not authorize, nor warrant, any NVE Corporation product for use in life support devices or systems or other critical applications, without the express written approval of the President of NVE Corporation. Specifications are subject to change without notice.
ISB-CB-002-03C January 2010
