On semiconductor Ncv7425evb User manual

Semiconductor Components Industries, LLC, 2011

November, 2011 −Rev. 0

1Publication Order Number:

EVBUM2045/D

NCV7425EVB

NCV7425 LIN Transceiver

with Voltage Regulator and

Reset Pin Evaluation Board

User's Manual

Introduction

This document describes the NCV7425EVB board for the

ON Semiconductor NCV7425 LIN Transceiver with

Voltage Regulator and Reset pin. The functionality and

major parameters can be evaluated with the NCV7425EVB

board.

The NCV7425 is a fully featured local interconnect

network (LIN) transceiver designed to interface between a

LIN protocol controller and the physical bus.

The NCV7425 LIN device is a member of the in-vehicle

networking (IVN) transceiver family of ON Semiconductor

that integrates a LIN v2.1 physical transceiver and a

low-drop voltage regulator. It is designed to work in harsh

automotive environment and is submitted to the TS16949

qualification flow.

Evaluation Board Features

One-row Pin Header Connecting to all Circuit Signals

Enables Easy Insertion of the Evaluation Board into a

more Complex Application Setup. The Header can be

Alternatively Assembled either Perpendicular or

Parallel with the Board Plane

Oscilloscope Test-points on All Circuit Signals

Reverse Protection and Decoupling on the Main

(Battery) Supply

Decoupling on VCC Regulator Output

Additional Pull-up Resistor on the RSTN Open-drain

Output

Filtering Circuit on the Switch-monitoring WAKE

Input

On-board Local Wakeup Switch

LIN-bus Termination and Optional ESD Protection

Good Thermal Connection of the Circuit’s Exposed Pad

to the Bottom Ground Plane

NCV7425 Key Features

LIN-Bus Transceiver

LIN Compliant to Specification Revision 2.1

(Backward Compatible to Versions 2.0 and 1.3)

and SAE J2602

Bus Voltage 45 V

Transmission Rate up to 20 kBaud

Integrated Slope Control for Improved EMI

Compatibility

Protection

Thermal Shutdown

Indefinite Short-circuit Protection on Pins LIN

and WAKE Towards Supply and Ground

Load Dump Protection (45 V)

Bus Pins Protected against Transients in an

Automotive Environment

ESD Protection Level for LIN, INH, WAKE and

Vbb up to 10 kV

Voltage Regulator

Two Device Versions: Output Voltage 3.3 V or 5 V

for Loads up to 150 mA

Under-voltage Detector with a Reset Output to the

Supplied Microcontroller

Over-current Limitation

INH Output for Auxiliary Purposes (Switching of an

External Pull-up or Resistive Divider towards

Battery, Control of an External Voltage Regulator

etc.)

Typical Applications

Automotive

Industrial Network

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EVAL BOARD USER’S MANUAL

NCV7425EVB

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Figure 1. NCV7425EVB

NCV7425

1VCC

VBB

710

LIN

GND

WAKE

INH

OTP_SUP

RxD

TxD

RSTN

STB

TEST

SOIC−16 LEAD

WIDE BODY

EXPOSED PAD

CASE 751AG

NCV7425 PIN CONNECTIONS

N.C.

Getting Started

Master/Slave Configuration

The NCV7425 evaluation board can be configured as

Master or Slave node. Furthermore, Master node LIN bus

pull-up resistance (RLIN) can be tied to VBB supply line or

to INH pin (See the figures below).

The EMC immunity of the Master-node device can be

further enhanced by adding a capacitor between the LIN

output and ground (CLIN). The optimum value of this

capacitor is determined by the length and capacitance of the

LIN bus, the number and capacitance of Slave devices, the

pull-up resistance of all devices (Master and Slave), and the

required time constant of the system.

VBB

LIN Bus

NCV7425

VBB

INH

LIN

RLIN

CLIN

VBB

LIN Bus

NCV7425

VBB

INH

LIN

RLIN

CLIN

VBB

LIN Bus

NCV7425

VBB

INH

LIN

CLIN

Figure 2. Master with Pull-up to VBB Figure 3. Master with Pull-up to INH Figure 4. Slave Configuration

Basic Connection

A simple LIN network configuration is shown in the

figure below. One Master and one Slave node is required

(Master/Slave Configuration).

MASTER Node

VBAT

SLAVE Node

LIN

GND

MCU

GND

VCC MASTER

MCU

GND

VCC SLAVE

Figure 5. NCV7425 Evaluation Setup Connection

NCV7425EVB

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Functional Description

Overall Functional Description

NCV7425 is designed as a master or slave node for the

LIN communication interface with an integrated 3.3 V or

5 V voltage regulator having a current capability up to

150 mA for supplying any external components

(microcontroller, CAN node, etc.).

NCV7425 contains the LIN transmitter, LIN receiver,

voltage regulator, power-on-reset (POR) circuits and

thermal shutdown (TSD). The LIN transmitter is optimized

for the maximum specified transmission speed of 20 kBaud

with EMC performance due to reduced slew rate of the LIN

output.

The junction temperature is monitored via a thermal

shutdown circuit that switches the LIN transmitter and

voltage regulator off when temperature exceeds the TSD

trigger level.

NCV7425 has four operating states (normal mode, low

slope mode, stand-by mode, and sleep mode) that are

determined by the input signals EN, WAKE, STB, and TxD.

Operating States

NCV7425 provides four operating states, two modes for

normal operation with communication, one stand-by

without communication and one low power mode with very

low current consumption - see Figure 6 and Table 1.

Table 1. MODE SELECTION

Mode Vcc RxD INH

LIN

Transceiver

30 kW

on LIN RSTN

Normal – Slope

(Note 1)

ON Low = Dominant State

High = Recessive State

High if STB = High

during State Transition;

Floating Otherwise

Normal Slope ON High

Normal – Low Slope

(Note 2)

ON Low = Dominant State

High = Recessive State

High if STB = High

during State Transition;

Floating Otherwise

Low Slope ON High

Stand-by (Note 3) ON Low after LIN Wakeup,

High Otherwise (Note 4)

Floating OFF OFF Controlled by VCC

Under-voltage

Monitor

Sleep OFF Clamped to Vcc (Note 4) Floating OFF OFF Low

1. The normal slope mode is entered when pin EN goes HIGH while TxD is in HIGH state during EN transition.

2. The low slope mode is entered when pin EN goes HIGH while TxD is in LOW state during EN transition. LIN transmitter gets on only after

TxD returns to high after the state transition.

3. The stand-by mode is entered automatically after power-up.

4. In Stand-by and Sleep mode, the High state is achieved by internal pull-up resistor to VCC.

Figure 6. NCV7425 State Diagram

−VCC: On

−LIN TRX: Off

−INH: Floating

−LIN Term.: Current Source

−RxD Pin: High/Low

−RSTN Pin: VCC_UV

Standby Mode

Vbb Power-up

VCC Under-voltage

EN Changes 1 −> 0 while STB = 1

EN Changes 0 −> 1 while TxD = 1

−VCC: On

−LIN TRX: On

−INH: High/Floating

−LIN Term.: 30 kW

−RxD Pin: LIN Data

−RSTN Pin: High

Normal Mode

(Normal Slope)

EN Changes 1 −> 0 while STB = 0

VCC Under-voltage

EN Changes 1 −> 0 while STB = 1

EN Changes 0 −> 1 while TxD = 0

EN Changes 1 −> 0 while STB = 0

Normal Mode

(Low Slope)

−VCC: On

−LIN TRX: On

−INH: High/Floating

−LIN Term.: 30 kW

−RxD Pin: LIN Data

−RSTN Pin: High

Sleep Mode

−VCC: Off

−LIN TRX: Off

−INH: Floating

−LIN Term.: Current Source

−RxD Pin: at VCC

−RSTN Pin: Low

PD20090610.01

LIN or Local Wake-up

Additional details of the NCV7425 operation and parameters can be found in the corresponding datasheet [1].

NCV7425EVB

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Schematic

Figure 7. NCV7425 LIN Transceiver with Voltage Regulator and Reset Pin Evaluation Board Schematic

Bill of Materials

Table 2. NCV7425 Evaluation Board Bill of Materials

Designator Description Value Footprint Manufacturer Manufacturer Part

Number

C1 Capacitor SMD 1.0 nF CAP0805 PHYCOMP 2238 580 15623

R1, R2 Resistor SMD 2.0 kW1206

0.25 W R1206 WELWYN WCR 1206 2K 2%

R3, R5 Resistor SMD 10 kWR0805 MULTICOMP MC 0.1 W 0805 1% 10K

C7 Capacitor SMD 10 nF CAP0603 EPCOS B37931K5103K60

C5 Capacitor SMD X7R 10 mF 10 V X7R CAP1206 KEMET C1206C106K8RAC

C3 Electrolytic Capacitor SMD 10 mF 50 V 6.3 x 6.3 SMD NICHICON UUD1H100MCL1GS

R4 Resistor SMD 33 kWR0805 MULTICOMP MC 0.1 W 0805 1% 33K

C4 Capacitor SMD 100 nF CAP0603 KEMET C0603C104K5RAC

C2 Capacitor SMD (Optional) (Optional) CAP0805 (Optional) (Optional)

D1 Diode SMD MRA4003 SMA ON Semiconductor MRA4003T3G

D4 LIN bus ESD protection diode ESD LIN SOD323 (Optional) (Optional)

L1 Resistor SMD

(Optional Ferrite) 0R R0805 MULTICOMP MC 0.1W 0805 0R

J1 SIL HEADER 12 pins

Right Angle HEADER 1X12 HDR1x12 MOLEX 90121-0772

D2, D3 Switching Diode SMD MMSD4148 SOD123 ON Semiconductor MMSD4148T1G

U1 LIN Transceiver with 3.3 V

or 5 V Voltage Regulator NCV7425 SOIC16_WB_

EP ON Semiconductor 3.3 V: NCV7425DW0R2G

5 V: NCV7425DW5R2G

SCOPEGND SCOPEGND; Wire Bridge SCOPEGND SCOPEGND - -

SW1 SWITCH SMD SPNO

6x6mm SMD SWITCH PB300 TYCO

ELECTRONICS FSM2JSMA

FT1, FT2, FT3,

FT4

Rubber feet

12,7 x 12,7 x 5,8 SUPPORT FEET FEET

12,7 x 12,7 3M SJ5018BLACK

TP1, TP2, TP4,

TP5, TP7, TP8,

TP9, TP10,

TP11, TP12

Testpin 200 SER.

Hole 1.0 Black

TP S200 H1.0

BLACK TESTPIN2 VERO 20-2137

NCV7425EVB

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PCB Drawings

Assembly Drawings

Figure 8. NCV7425EVB PCB

Top Assembly Drawing

Figure 9. NCV7425EVB PCB

Bottom Assembly Drawing

Composite Drawings

Figure 10. NCV7425EVB PCB

Top Composite Drawing

Figure 11. NCV7425EVB PCB

Bottom Composite Drawing (Mirrored)

PCB Preview

Figure 12. NCV7425EVB PCB Top Side View Figure 13. NCV7425EVB PCB Bottom Side View

NCV7425EVB

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References

[1] On Semiconductor, NCV7425 Product Preview Revision P0, August 2011.

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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

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