ATMEL ATA6621

Features
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Supply Voltage up to 40V
Operating Voltage VS = 5V to 18V
Slew Rate Control according to LIN Specification 2.0
Supply Current during Sleep Mode Typically 10 µA
Supply Current in Silent Mode Typically 40 µA
Linear Low-drop Voltage Regulator:
– Normal Mode: VCC = 5V ±2%/50 mA
– Silent Mode: VCC = 5V ±7%/50 mA
– Sleep Mode: VCC is Switched Off
VCC Undervoltage Detection (10 ms Reset time) and Watchdog Reset Logically
Combined at Output NRES
Possibility of Boosting the Voltage Regulator with an External NPN Transistor
LIN Physical Layer according to LIN Specification 2.0
Wake-up Capability via LIN Bus or WAKE Pin
Wake-up Recognition
TXD Time-out Timer
60V Load Dump Protection at LIN Pin
Bus Pin is Overtemperature and Short Circuit Protected versus GND and Battery
Adjustable Watchdog Time via External Resistor
Positive and Negative Trigger Input for Watchdog
5V CMOS Compatible I/O Pins to MCU
Analog Temperature Monitor Output
High EMC and ESD Level
Package: QFN 5 × 5 with 20 Pins
LIN Transceiver
with 5V
Regulator and
Watchdog
ATA6621
1. Description
The ATA6621 is a fully integrated LIN transceiver, complying with the LIN specification, and with a low-drop voltage regulator for 5V/50 mA output and a window
watchdog adjustable via an external resistor. In this QFN20 package, the voltage regulator is able to source 50 mA at VS = 18V even at an ambient temperature of 105°C.
The output current of the regulator can be boosted by using an external NPN transistor. This combination makes it possible to develop simple, but powerful and cheap,
slave nodes in LIN bus systems. ATA6621 is designed to handle the low speed data
communication in vehicles, for example, in convenience electronics. Improved slope
control at the LIN driver ensures secure data communication up to 20 kBaud. The bus
output is capable of withstanding 60V. Sleep Mode and Silent Mode guarantee a very
low current consumption.
Rev. 4887B–AUTO–01/06
Figure 1-1.
Block Diagram
20
VCC
9
VS
Normal
Mode
Receiver
RXD
7
VS
Filter
LIN
4
WAKE
Wake-up Bus Timer
VCC
Slew Rate Control
TXD
Time-out
Timer
11
TXD
Short Circuit and
Overtemperature
Protection
Control Unit
EN
GND
TEMP
1
5
Debounce
Time
Standby Mode
VCC
Normal Mode
5V ± 2%/50 mA
Silent Mode
5V ± 7%/50 mA
19
Undervoltage
Reset
12
18
VCC
PVCC
NRES
17
16
GND
Internal Testing
Unit
OUT
Watchdog
Adjustable
Watchdog
Oscillator
13
WD_OSC
VCC
15
MODE
2
14
2
TM
PTRIG
3
NTRIG
ATA6621
4887B–AUTO–01/06
ATA6621
2. Pin Configuration
EN
VCC
PVCC
TEMP
GND
Pinning QFN20
VS
Figure 2-1.
20
19
18
17
16
1
15
MODE
14
TM
13
WD_OSC
12
NRES
11
TXD
ATA6621
Table 2-1.
4
GND
5
6
7
8
9
10
NC
WAKE
MLP 5 mm × 5 mm
0.65 mm pitch
20 lead
RXD
3
NC
NTRIG
LIN
2
NC
PTRIG
Pin Description
Pin
Symbol
1
EN
Function
Enables the device into Normal Mode
2
PTRIG
High-level watchdog trigger input from microcontroller; if not needed, leave open or connect to GND
3
NTRIG
Low-level watchdog trigger input from microcontroller; if not needed, leave open or connect to VCC
4
WAKE
High-voltage input for local wake-up request; if not needed, connect to VS
5
GND
System ground
6
NC
Not connected
7
LIN
LIN bus line input/output
8
NC
Not connected
9
RXD
Receive data output
10
NC
Not connected
11
TXD
Transmit data input; active low output (strong pull down) after a local wake-up request
12
NRES
13
WD_OSC
Output undervoltage and watchdog reset
Watchdog oscillator
14
TM
For factory testing only (tie to ground)
15
MODE
For factory testing only (tie to ground)
16
GND
Additional ground
17
TEMP
Chip temperature output pin
18
PVCC
5V regulator sense input pin
19
VCC
5V regulator output/driver pin
20
VS
Backside
Battery supply
Heat slug is connected to GND (pin 5)
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3. Functional Description
3.1
Supply Pin (VS)
The LIN operating voltage is VS = 5V to 18V. An undervoltage detection is implemented to disable transmission if VS falls below 5V in order to avoid false bus messages. After switching on
VS, the IC starts with the Pre Normal Mode and the voltage regulator is switched on (that is,
5V/50 mA output capability).
The supply current in Sleep Mode is typically 10 µA, and 40 µA in Silent Mode.
3.2
Ground Pin (GND)
The IC is neutral on the LIN pin in case of GND disconnection; it can handle a ground shift up to
3V for supply voltage at the VS pin above 9V.
3.3
Voltage Regulator Output Pin (VCC)
The internal 5V voltage regulator is capable of driving loads with up to 50 mA of current consumption; it is able to supply the microcontroller and other ICs on the PCB. It is protected
against overloads by means of current limitation and overtemperature shutdown. Furthermore,
the output voltage is monitored and will cause a reset signal at the NRES output pin if the output
voltage drops below a defined threshold Vthun. To boost up the maximum load current, an external NPN transistor may be used with its base connected to the VCC pin and its emitter
connected to PVCC.
3.4
Voltage Regulator Sense Pin (PVCC)
This is the sense input pin of the 5V voltage regulator. For normal applications (that is, when
only using the internal output transistor), this pin is connected to the VCC pin. If an external
boosting transistor is used, the PVCC pin must be connected to the output of this transistor, its
emitter terminal.
3.5
Bus Pin (LIN)
A low side driver with internal current limitation and thermal shutdown, and an internal pull-up
resistor in compliance with LIN specification 2.0 is implemented. This is a self-adapting current
limitation; that is, during current limitation, as the chip temperature increases, the current
decreases. The allowed voltage range is between –40V and +60V. Reverse currents from the
LIN bus to VS are suppressed, even in case of ground shifts or battery disconnection. LIN
receiver thresholds are compatible to the LIN protocol specification. The fall time from recessive
bus state to dominant, and the rise time from dominant bus state to recessive are slope
controlled.
3.6
Input Pin (TXD)
This pin is the microcontroller interface to control the state of the LIN output. TXD must be pulled
to ground in order to have the LIN bus low. If TXD is high, the LIN output transistor is turned off
and the bus is in the recessive state, pulled up by the internal resistor.
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ATA6621
3.7
TXD Dominant Time-out Function
The TXD input has an internal pull-up resistor. An internal timer prevents the bus line from being
driven permanently in the dominant state. If TXD is forced to low longer than tDOM > 20 ms, the
LIN bus driver is switched to the recessive state.
3.8
Output Pin (RXD)
This pin reports the state of the LIN bus to the microcontroller. LIN high (recessive state) is
reported by a high level at RXD, LIN low (dominant state) is reported by a low level at RXD. The
output has an internal pull-up structure with typically 5 kΩ to VCC. The AC characteristics can be
defined with an external load capacitor of 20 pF.
The output is short-circuit protected. In Unpowered Mode (that is, VS = 0V), RXD is switched off.
3.9
Enable Input Pin (EN)
This pin controls the operation mode of the interface. If EN is high, the interface is in Normal
Mode, with transmission paths from TXD to LIN and from LIN to RXD both being active. The VCC
voltage regulator is operating with 5V ±2%/50 mA output capability.
If EN is switched to low while TXD is still high, the device is forced to Silent Mode. No data transmission is then possible and the current consumption is reduced to IVS = 50 µA. The current
capability of the VCC regulator is also 50 mA, but the VCC tolerance is between 4.65V and 5.35V.
If EN is switched to low while TXD is low, the device is forced to Sleep Mode. No data transmission is possible and the voltage regulator is switched off.
3.10
Wake Input Pin (WAKE)
This pin is a high voltage input used to wake the device up from Sleep Mode. It is usually connected to an external switch in the application to generate a local wake-up. A pull-up current
source with typically 10 µA is implemented.
If you don’t need a local wake-up in your application, connect pin WAKE directly to pin VS.
3.11
MODE and TM Input Pins
These inputs are used for a special test mode of the watchdog in final production measurement
at Atmel. In the application, they are always connected to GND.
Wake-up events from Sleep Mode:
• LIN bus
• WAKE pin
• EN pin
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4887B–AUTO–01/06
3.12
Modes of Operation
Figure 3-1.
Modes of Operation
Unpowered Mode, VBat = 0V
b
a
b
b
Pre Normal Mode
VCC: 5V/50 mA with undervoltage reset
c+d
b
Communication: OFF
EN = 1
c+d
EN = 0
Go to silent command
TXD = 1
Local wake-up event
Normal Mode
VCC: 5V ±2%/50 mA
with undervoltage
reset
Communication: On
EN = 0
EN = 0
Normal Mode
VCC: 5V ±7%/50 mA
with undervoltage reset
Communication: OFF
Go to sleep command
TXD = 0
Local wake-up event
Sleep Mode
VCC: switched off
Communication: Off
EN = 1
a: VS > 5V
b: VS < 4V
c: Bus wake-up event
d: Wake-up from wake-up switch
3.12.1
Normal Mode
This is the normal transmitting and receiving mode. The voltage regulator is in normal mode and
can source 50 mA. The undervoltage detection is activated. The watchdog needs a trigger signal
from PTRIG or NTRIG to avoid resets at NRES.
3.12.2
Silent Mode
A falling edge at EN while TXD is high switches the IC into Silent Mode. The TXD signal has to
be logic high during the Mode Select window (Figure 3-2 on page 7). For EN and TXD either two
independent outputs can be used, or two outputs from the same microcontroller port; in the second case, the mode change is only one command. In Silent Mode, the transmission path is
disabled. Supply current from VBat is typically IVSsi = 40 µA with no load at the VCC regulator.
The overall supply current from VBat is the addition of 40 µA plus the VCC regulator output current
IVCCs.
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ATA6621
4887B–AUTO–01/06
ATA6621
In Silent Mode, the 5V regulator is in low tolerance mode (4.65V to 5.35V) and can source up to
50 mA. The internal slave termination between pin LIN and pin VS is disabled to minimize the
power dissipation in case pin LIN is shorted to GND. Only a weak pull-up current (typically
10 µA) between pin LIN and pin VS is present.
The Silent Mode voltage tolerance is sufficient to run the internal timers of the microcontroller.
The undervoltage reset is now VccthS < 4.4V. If an undervoltage condition occurs, the NRES is
switched to low and the ATA6621 changes state to Pre Normal Mode.
A falling edge at pin LIN followed by a dominant bus level maintained for a certain time period
(Tbus) results in a remote wake-up request. The device switches from Silent Mode to Pre Normal
Mode. The internal LIN slave termination resistor is switched on. The remote wake-up request is
indicated by a low level at pin RXD to interrupt the microcontroller. (Figure 3-5 on page 10)
With EN high, you can switch directly from Silent Mode to Normal Mode.
Figure 3-2.
Switch to Silent Mode
Sleep Mode
EN
TXD
Mode Select window
Td = 3.2 µs
NRES
VCC
Delay time Sleep Mode
Td_sleep = maximum 20 µs
LIN
LIN switches directly to recessive mode
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4887B–AUTO–01/06
Figure 3-3.
LIN Wake-up Waveform Diagram (from Silent Mode)
Pre Normal Mode
Normal Mode
LIN bus
RXD
High
Low
High
Bus wake-up filtering time
Tbus
VCC
Voltage
Regulator
Silent Mode 4.5V to 5.5V/50 mA
Pre normal Mode 5V/50 mA
Regulator Wake-up time
EN
NRES
3.12.3
Normal Mode
5V/50 mA
EN High
Node In Silent Mode
If undervoltage, switch to Prenormal Mode
Undervoltage detection active
Sleep Mode
A falling edge at EN while TXD is low switches the IC into Sleep Mode. The TXD Signal has to
be logic low during the Mode Select window (Figure 3-4 on page 9), see section “Silent Mode”
on page 6.
In Sleep Mode the transmission path is disabled. Supply current from V Bat is typically
IVSsleep = 10 µA. The VCC regulator is switched off. NRES and RXD are low. The internal slave
termination between pin LIN and pin VS is disabled to minimize the power dissipation in case pin
LIN is shorted to GND. Only a weak pull-up current (typically 10 µA) between pin LIN and pin VS
is present.
A falling edge at pin LIN followed by a dominant bus level maintained for a certain time period
(Tbus) results in a remote wake-up request. The device switches from Sleep Mode to Pre Normal
Mode. The VCC regulator is activated and the internal LIN slave termination resistor is switched
on. The remote wake-up request is indicated by a low level at pin RXD to interrupt the microcontroller. (Figure 3-5 on page 10)
With EN high you can switch directly from Silent Mode to Normal Mode. In the application where
the ATA6621 supplies the microcontroller, wake-up from Sleep Mode is only possible via LIN or
pin WAKE.
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4887B–AUTO–01/06
ATA6621
Figure 3-4.
Switch to Sleep Mode
Sleep Mode
EN
TXD
Mode Select window
Td = 3.2 µs
NRES
VCC
Delay time Sleep Mode
Td_sleep = maximum 20 µs
LIN
LIN switches directly to recessive mode
3.12.4
Pre Normal Mode
At system power-up the device automatically switches to Pre Normal Mode. The voltage regulator is switched on VCC = 5V ±2%/50 mA (see Figure 3-6 on page 12). The NRES output switches
to low for tres = 10 ms and sends a reset to the microcontroller. LIN communication is switched
off and the watchdog is active. The ATA6621 stays in this mode until EN is switched to high.
If VBattery (VS < 4V) is powered down during Silent Mode or Sleep Mode, the IC powers up into
Pre Normal Mode.
3.12.5
Unpowered Mode
If you connect battery voltage to the application circuit, the voltage at the VS pin increases due
to the block capacitor (Figure 3-6 on page 12). When VS becomes higher than the VS undervoltage threshold VS_th, the IC mode changes from Unpowered Mode to Pre Normal Mode. The VCC
output voltage reaches its nominal value after tVCC. This time depends on the VCC capacitor and
the load.
The NRES is low for the reset time delay treset. During this time, no mode change is possible.
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4887B–AUTO–01/06
Figure 3-5.
LIN Wake-up Waveform Diagram from Sleep Mode
Pre Normal Mode
Normal Mode
LIN bus
RXD
Low
Low or floating
High
Bus wake-up filtering time
Tbus
VCC
Voltage
Regulator
On state
Off state
Node ln
operation
Regulator Wake-up time
EN High
EN
Node In Silent Mode
Reset
time
NRES
Low or floating
Microcontroller
start-up time delay
Table 3-1.
10
Table of Modes
Mode of
Operation
Transceiver
VCC
WD_OSC
TEMP
RXD
LIN
Pre Normal
Off
5V
2.5V
2V
5V
RECESSIVE
Normal
On
5V
2.5V
2V
5V
RECESSIVE
Silent
Off
5V
0V
0V
5V
RECESSIVE
Sleep
Off
0V
0V
0V
0V
RECESSIVE
ATA6621
4887B–AUTO–01/06
ATA6621
3.13
Wake-up Scenarios
3.13.1
Remote Wake-up via Dominant Bus State
A falling edge at pin LIN followed by a dominant bus level maintained for a certain time period
(TBUS) results in a remote wake-up request. The device switches to Pre Normal Mode. The VCC
voltage regulator is activated, and the internal slave termination resistor is switched on. The
remote wake-up request is indicated by a low level at pin RXD to generate an interrupt in the
microcontroller. The watchdog needs a trigger signal from PTRIG or NTRIG within the lead time
tD to avoid resets at NRES. (Figure 3-2 on page 7)
3.13.2
Local Wake-up via Pin Wake
A falling edge at pin WAKE followed by a low level maintained for a certain time period (TWAKE)
results in a local wake-up request. The extra long wake-up time (TWAKE) ensures that no transients as defined in ISO7637 create a wake-up. The device switches to Pre Normal Mode. The
internal slave termination resistor is switched on. The local wake-up request is indicated by a low
level at pin RXD to generate an interrupt in the microcontroller. The watchdog needs a trigger
signal from PTRIG or NTRIG within the lead time tD to avoid resets at NRES.
3.13.3
Wake-up Source Recognition
The device can distinguish between a local wake-up request (pin WAKE) and a remote wake-up
request (dominant LIN bus state). The wake-up source can be read on pin TXD in Pre Normal
Mode. If an external pull-up resistor (typically 5 kΩ) on pin TXD to the power supply of the microcontroller has been added, a high level indicates a remote wake-up request (weak pull down at
pin TXD) and a low level indicates a local wake-up request (strong pull down at pin TXD). The
wake-up request flag (signalled on pin RXD) as well as the wake-up source flag (signalled on pin
TXD) are reset immediately, if the microcontroller sets pin EN to high (Figure 3-2 on page 7 and
Figure 3-3 on page 8).
3.14
Fail-safe Features
• During a short circuit at LIN, the output limits the output current to IBUS_LIM. Due to the power
dissipation, the chip temperature exceeds TLINoff and the LIN output is switched off. The chip
cools down and after a hysteresis of Thys, switches the output on again. During LIN
overtemperature switch-off, the VCC regulator works independently.
• The reverse current at pin LIN is very low (< 3 µA) during loss of VBAT or GND. This is optimal
behavior for bus systems where some slave modes are supplied from battery or ignition.
• During a short circuit at VCC, the output limits the output current to IVCCn. Because of
undervoltage, NRES switches to low and sends a reset to the microcontroller. The IC
switches into Pre Normal Mode. If the chip temperature exceeds the value TVCCoff, the VCC
output switches off. The chip cools down and after a hysteresis of Thys, switches the output on
again. Because of Pre Normal Mode, the VCC voltage will switch on again although EN is
switched off from the microcontroller. The microcontroller can start its normal operation.
• Pin EN provides a pull-down resistor to force the transceiver into recessive mode if EN is
disconnected.
• Pin RXD is set floating if VBat is disconnected.
• Pin TXD provides a pull-up resistor to force the transceiver into recessive mode if TXD is
disconnected.
• If the WD_OSC pin has a short circuit to GND or the resistor is disconnected, the watchdog
oscillator runs with a high frequency and guarantees a reset in any condition.
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4887B–AUTO–01/06
• The WD_OSC pin is a constant voltage regulator which supplies 2.5V for the external resistor
ROSC to adjust the watchdog timing. This output is short circuit protected. A short circuit to
GND causes a reset a pin NRES after typically 4 ms. An open circuit causes a reset at pin
NRES after typically 7 ms.
3.15
Voltage Regulator
The voltage regulator needs an external capacitor for compensation and to smooth the disturbances from the microcontroller. It is recommend to use an electrolytic capacitor with C > 1.8 µF
and a tantalum capacitor with C = 100 nF. The values of these capacitors can be varied by the
customer, depending on the application.
During mode change from Silent to Normal Mode, the voltage regulator ramps up to 6V for only
a few microseconds before it drops back to 5V. This behavior depends on the value of the load
capacitor. With 4.7 µF, the overshoot voltage has its greatest value. This voltage decreases with
higher or lower load capacitors.
The main power dissipation of the IC is created from the VCC output current IVCC , which is
needed for the application.
In Figure 3-7 on page 13 you see the safe operating range of the ATA6621.
Figure 3-6.
VCC Voltage Regulator: Ramp Up and Undervoltage
VS
12V
5.5V
3V
t
VCC
5V
Vthun
tvcc
tres
tres_f
t
NRES
5V
t
12
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4887B–AUTO–01/06
ATA6621
Figure 3-7.
Power Dissipation: Safe Operating Area versus VCC Output Current and Supply
Voltage VS at Different Ambient Temperatures
55
Tamb = 105˚C
50
45
IVCC (mA)
40
Tamb = 125˚C
35
30
25
20
15
10
5
0
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
VS (V)
3.16
Watchdog
The watchdog anticipates a trigger signal from the microcontroller at the NTRIG (negative edge)
or the PTRIG (positive edge) input within a period time window of Twd. The trigger signal must
exceed a minimum time ttrigmin > 3 µs. If a triggering signal is not received, a reset signal will be
generated at output NRES. The timing basis of the watchdog is provided by the internal oscillator, of which the time period Tosc is adjustable via the external resistor Rwd_osc (10 kΩ to 120 kΩ).
In Silent or Sleep Mode, the watchdog is switched off to reduce current consumption.
Minimum time for first watchdog pulse is required after the undervoltage reset at NRES disappears and is defined as lead time td.
3.16.1
Typical Timing Sequence with Rwd_osc = 51 kΩ
The trigger signal Twd is adjustable between 2.9 ms and 33 ms via the external resistor Rwd_osc.
For example, with an external resistor of Rwd_oscSC = 51 kΩ ±1%, the typical parameters of the
watchdog come out as follows:
tOSC = 12.5 µs due to 51 kΩ
td = 3922 × 12.5 µs = 49 ms
t1 = 800 × 12.5 µs = 10 ms
t2 = 840 × 12.5 µs = 10.5 ms
tnres = 157 × 12.5 µs = 1.96 ms
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4887B–AUTO–01/06
After ramping up the battery voltage, the 5V regulator is switched on. The reset output NRES
stays low for the time treset (typically 10 ms), then it switches to high and the watchdog waits for
the watchdog sequence from the microcontroller. This lead time td follows after the reset and is
td = 49 ms. In this time, the first watchdog pulse from the microcontroller is required. If the trigger
pulse NTRIG (or PTRIG, as the case may be) occurs during this time, the time t1 starts immediately. If no trigger signal occurs during the time td, a watchdog reset with tNRES = 1.96 ms will
reset the microcontroller after td = 49 ms. The times t1 and t2 have a fixed relationship with each
other. A triggering signal from the microcontroller is anticipated within the time frame of
t2 = 10.5 ms. To avoid false triggering from glitches, the trigger pulse must be longer than
ttrigg > 3 µs. This slope serves to restart the watchdog sequence. Should the triggering signal fail
in this open window t2, the NRES output will be drawn to ground after t2. A triggering signal during the closed window t1 causes NRES to immediately switch low.
Figure 3-8.
Timing Sequence with RWD_OSC = 51 kΩ
VCC = 5V
Undervoltage Reset
NRES
Watchdog Reset
treset = 10 ms
tnres = 1.9 ms
td = 49 ms
t1
t1 = 10 ms
t2
t2 = 10.5 ms
twd
NTRIG
PTRIG
ttrigg > 3 µs
3.16.2
Worst Case Calculation with RWO_OSC = 51 kΩ
The internal oscillator has a tolerance of ±20%. This means that t1 and t2 can also vary by ±20%.
The worst case calculation for the watchdog period Twd the microcontroller has to provide is calculated as follows.
The ideal watchdog time Twd is between (t1maximum) and (t1 minimum plus t2 minimum).
t1,min = 0.8 × t1 = 8 ms, t1,max = 1.2 × t1 = 12 ms
t2,min = 0.8 × t2 = 8.4 ms, t2,max = 1.2 × t2 = 12.6 ms
Twdmax = t1min + t2min = 8 ms + 8.4 ms = 16.4 ms
Twdmin = t1max = 12 ms
Twd = 14.2 ms ±2.2 ms (±15%)
A microcontroller with an oscillator tolerance of ±15% is sufficient to supply the trigger inputs
correctly within the time period of Twd = 14.2 ms (±15%) in an application with Rwd_osc = 51 kΩ.
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Table 3-2.
3.17
Table of Watchdog Timings
Rwd_osc
kΩ
Oscillator
Period
tosc/µs
Lead
Time
td/ms
Closed
Window
t1/ms
Open Window
t2/ms
Trigger Period from
microcontroller
Reset time
twd/ms
tnres/ms
10
2.6
10.2
2.08
2.18
51
12.5
49.4
10
10.5
14.2
1.96
91
22.4
87.8
17.92
18.82
25.45
3.52
120
29
113.7
23.2
24.36
32.94
4.55
2.90
0.41
Temperature Monitor at Pin TEMP
In addition to the internal temperature monitoring of the voltage regulator, an additional sensor
measures the junction temperature and provides a linearized voltage at the TEMP pin. Together
with the analog functions of the microcontroller (for example, the analog comparator and the
Analog-to-digital converter (ADC)), this enables the application to detect overload conditions
and to take corresponding measures in order to prevent damage. An external capacitor buffers
the voltage due to the input current of the ADC.
The sensor itself is built out of three diodes which are supplied by an internal BIAS current in Pre
Normal Mode and Normal Mode. The typical voltage at T = 27°C is Vtemp = 2.2V with a typical
negative temperature coefficient of VTC,TEMP = –5.4 mV/k.
Figure 3-9.
Temperature Monitor
VCC
20 µA
TEMP
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4. Absolute Maximum Ratings
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating
only and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of this
specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
Parameters
Symbol
Max
Unit
–0.3
+40
+44
V
–40
–150
+40
+100
V
–0.3
+6.5
V
LIN
- DC voltage
- Transient voltage
–40
–150
+60
+100
V
VCC
DC voltage
–0.3
6.5
V
VS
- Continuous supply voltage
- Transient voltage (load dump)
WAKE DC and transient voltage
(with 33 kΩ serial resistor)
Transient voltage due to ISO7637 (coupling 1 nF)
Logic pins (RXD, TXD, EN, NRES, PTRIG, NTRIG,
PVCC, WD_OSC, TEMP)
Min
Typ
ESD (DIN EN 6100-4-2)
According LIN EMC Test Specification 1.3
- Pin VS, LIN to GND
- Pin WAKE (33 kΩ serial resistor)
±6
±5
KV
KV
ESD HBM
- All pins according to ESD S 5.1
±2
KV
CDM ESD STM 5.3.1-1999
- All pins
±1
KV
Junction temperature
Tj
–40
+150
°C
Storage temperature
Ts
–55
+150
°C
Operating ambient temperature
Ta
–40
+125
°C
10
K/W
Thermal resistance junction to heat slug
Rthjc
Thermal resistance junction to ambient, where
heat slug is soldered to PCB
Rthja
35
K/W
Thermal shutdown of VCC regulator
150
165
170
°C
Thermal shutdown of LIN output
150
165
170
°C
Thermal shutdown hysteresis
16
10
°C
ATA6621
4887B–AUTO–01/06
ATA6621
5. Electrical Characteristics
5V < VS < 18V, Tamb = –40°C to +125°C
No.
1
Parameters
Test Conditions
Pin
Symbol
Min
VS
5
Typ
Max
Unit
Type*
18
V
A
VS Pin
1.1
Nominal DC voltage
range
1.2
Supply current in Sleep
Mode
Sleep Mode
Vlin >VBat – 0.5V
VBat < 14V (25°C to 125°C)
IVSsleep
10
20
µA
A
1.3
Supply current in Silent
Mode
Bus recessive;
VBat < 14V (25°C to 125°C)
Without load at VCC
IVSsi
40
55
µA
A
1.4
Supply current in Normal Bus recessive
Mode
Without load at VCC
IVSrec
4
mA
A
1.5
Supply current in Normal Bus dominant
Mode
VCC load current 50 mA
IVSdom
55
mA
A
1.6
VS undervoltage
threshold
5
V
A
1.7
VS undervoltage
threshold hysteresis
V
A
8
mA
A
0.4
V
A
2
VSth
4.0
VSth_hys
4.5
0.2
RXD Output Pin
Normal Mode; VLIN = 0V
VRXD = 0.4V
2.1
Low-level input current
2.2
Low-level output voltage IRXD = 1 mA
VRXDL
2.3
Internal 5 kΩ resistor to
VCC
RRXD
3
7
kΩ
A
3
IRXD
2
5
TXD Input Pin
3.1
Low-level voltage input
VTXDL
–0.3
+1.5
V
A
3.2
High-level voltage input
VTXDH
3.5
VCC +
0.3V
V
A
3.3
Pull-up resistor
VTXD = 0V
RTXD
125
600
kΩ
A
3.4
High-level leakage
current
VTXD = 5V
ITXD
–3
+3
µA
A
3.5
Pre Normal Mode;
Low-level input current at VLIN = VBattery
VWAKE = 0V
local wake-up request
VTXD = 0.4V
ITXDwake
2
8
mA
A
250
5
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter
17
4887B–AUTO–01/06
5. Electrical Characteristics (Continued)
5V < VS < 18V, Tamb = –40°C to +125°C
No.
Parameters
4
EN Input Pin
4.1
Test Conditions
Pin
Low-level voltage input
Symbol
Min
VENL
Max
Unit
Type*
–0.3
+1.5
V
A
VENH
3.5
VCC +
0.3V
V
A
600
kΩ
A
+3
µA
A
V
A
4.2
High-level voltage input
4.3
Pull-down resistor
VEN = 5V
REN
125
4.4
Low-level input current
VEN = 0V
IEN
–3
4.2
5
Typ
250
NRES Output Pin
5.1
High-level output voltage
VS ≥ 5.5V;
Inres = –1 mA
VNRESH
5.2
Low-level output voltage
VS ≥ 5.5V;
Inres = –1 mA
VNRESL
0.4
V
A
5.3
Low-level output low
10 kΩ to VCC;
VCC = 0.8V
VNRESLL
0.3
V
A
5.4
Undervoltage reset time
VVS ≥ 5.5V
CNRES = 20 pF
treset
13
ms
A
5.5
Reset debounce time for VVS ≥ 5.5V
CNRES = 20 pF
falling edge
tres_f
5
µs
A
6
7
Voltage Regulator VCC Pin in Normal and Pre Normal Mode
6.1
Output voltage VCC
5.5V < VS < 18V
(0 mA to 50 mA)
VCCnor
4.9
5.1
V
A
6.2
Output voltage VCC at
low VS
3.3V < VS < 5.5V
VCClow
VVS
– VD
5.1
V
A
6.3
Regulator drop voltage
VS > 4.0V, IVCC = –20 mA
VD1
250
mV
A
6.4
Regulator drop voltage
VS > 4.0V, IVCC = –50 mA
VD2
500
mV
A
6.5
Regulator drop voltage
VS > 3.3V, IVCC = –15 mA
VD3
200
mV
A
6.6
Output current
VS > 3V
IVCC
–50
mA
A
6.7
Output current limitation VS > 0V
IVCCs
–200
–130
mA
A
6.8
Load capacity
1Ω < ESR < 5Ω
Cload
1.8
2.2
µF
D
6.9
VCC undervoltage
threshold
Referred to VCC
VS > 5.5V
VthunN
4.4
V
A
6.10
Hysteresis of
undervoltage threshold
Referred to VCC
VS > 5.5V
Vhysthun
40
mV
A
6.11
Ramp up time VS > 5.5V CVCC = 2.2 µF
to VCC > 4.9V
Rload at VCC: 100Ω
2
ms
A
7
Voltage Regulator VCC Pin in Silent Mode
4.8
1
tVCC
7.1
Output voltage VCC
5.5V < VS < 18V
(0 mA to 50 mA)
VCCnor
4.65
5.35
V
A
7.2
Output voltage VCC at
low VS
3.3V < VS < 5.5V
VCClow
VVS
– VD
5.1
V
A
7.3
Regulator drop voltage
VS > 3.3V, IVCC = –15 mA
200
mV
A
VD
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter
18
ATA6621
4887B–AUTO–01/06
ATA6621
5. Electrical Characteristics (Continued)
5V < VS < 18V, Tamb = –40°C to +125°C
No.
Parameters
Test Conditions
7.4
At VCC undervoltage
threshold the state
switches back to Pre
Normal Mode
7.5
Hysteresis of
undervoltage threshold
7.6
Output current limitation VS > 0V
8
Pin
Symbol
Min
Referred to VCC
VS > 5.5
VthunS
3.9
Referred to VCC
VS > 5.5V
Vhysthun
40
IVCCs
–200
Typ
Max
Unit
Type*
4.4
V
A
mV
D
mA
A
VS
V
A
–130
LIN Bus Driver: Bus Load Conditions:
Load1 (Small): 1 nF, 1 kΩ; Load2 (Large): 10 nF, 500Ω; RRXD = 5 kΩ; CRXD = 20 pF
10.5, 10.6 and 10.7 Specify the Timing Parameters for Proper Operation at 20 Kbps
8.1
Driver recessive output
voltage
Load1 / Load2
VBUSrec
8.2
Driver dominant voltage
VVS = 7V
Rload = 500Ω
V_LoSUP
1.2
V
A
8.3
Driver dominant voltage
VVS = 18V
Rload = 500Ω
V_HiSUP
2
V
A
8.4
Driver dominant voltage
VBUSdom_DRV_LoSUP
VVS = 7V
Rload = 1000Ω
V_LoSUP_1k
0.6
V
A
8.5
Driver dominant voltage
VVS = 18V
Rload = 1000Ω
V_HiSUP_1k_
0.8
V
A
8.6
Pull-up resistor to VS
The serial diode is mandatory
RLIN
20
60
kΩ
A
8.7
Self-adapting current
limitation
VBus = VBatt_max
Tj = 125°C
Tj = 27°C
Tj = –40°C
IBUS_LIM
52
80
120
110
170
230
mA
mA
mA
A
8.8
Input leakage current at
the receiver including
pull-up resistor as
specified
Input leakage current
Driver off
VBUS = 0V
VBattery = 12V
IBUS_PAS_dom
–1
mA
A
8.9
Leakage current LIN
recessive
Driver off
8V < VBattery < 18V
8V < VBUS < 18V
VBUS ≥ VBatt
IBUS_PAS_rec
8.10
Leakage current when
control unit disconnected
GNDDevice = VS
from ground. Loss of
VBattery = 12V
local ground must not
0V < VBUS < 18V
affect communication in
the residual network
8.11
Node has to sustain the
current that can flow
VBattery disconnected
under this condition. Bus VSUP_Device = GND
must remain operational 0V < VBUS < 18V
under this condition
IBUS_NO_gnd
IBUS
0.9 VS
–10
30
15
20
µA
A
0.5
10
µA
A
0.5
3
µA
A
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter
19
4887B–AUTO–01/06
5. Electrical Characteristics (Continued)
5V < VS < 18V, Tamb = –40°C to +125°C
No.
Parameters
Test Conditions
Pin
Symbol
Min
Typ
Max
Unit
Type*
VBUS_CNT
0.475 VS
0.5
VS
0.525 –
VS
V
A
9
LIN Bus Receiver
9.1
Center of receiver
threshold
9.2
Receiver dominant state VEN = 5V
VBUSdom
–27
0.4 VS
V
A
9.3
Receiver recessive state VEN = 5V
VBUSrec
0.6 VS
40
V
A
9.4
Receiver input hysteresis VHYS = Vth_rec – Vth_dom
VBUShys
0.028 VS
0.175 VS
V
A
9.5
Wake detection LIN
High-level input voltage
VLINH
VS – 1V
VS + 0.3V
V
A
9.6
Wake detection LIN
Low-level input voltage
VLINL
–27
VS – 3.3V
V
A
10
Internal Timers
VBUS_CNT =
(Vth_dom + Vth_rec) / 2
Initializes a wake-up signal
0.1 VS
10.1
Dominant time for wakeVLIN = 0V
up via LIN bus
Tbus
30
90
150
µs
A
10.2
Time delay for mode
change from Pre Normal
VEN = 5V
to Normal Mode via pin
EN
Tnorm
5
15
20
µs
A
10.3
Time delay for mode
change from Normal into VEN = 0V
Sleep Mode via pin EN
Tsleep
2
7
12
µs
A
10.4
TXD dominant time-out
timer
VTXD = 0V
Tdom
5
10
20
ms
A
Duty cycle 1
THRec(max) = 0.744 × VS;
THDom(max) = 0.581 × VS;
VS = 7.0V to 18V; tBit = 50 µs
D1 = tbus_rec(min) / (2 × tBit)
D1
0.396
10.6
Duty cycle 2
THRec(min) = 0.422 × VS;
THDom(min) = 0.284 × VS;
VS = 7.0V to 18V; tBit = 50 µs
D2 = tbus_rec(max) / (2 × tBit)
D2
10.7
Slope time falling and
rising edge at LIN
Slope time dominant and
recessive edges
10.8
Time of low pulse for
wake-up via pin WAKE
VWAKE = 0V
10.5
11
A
0.581
TSLOPE_fall
TSLOPE_rise
3.5
TWAKE
60
130
A
22.5
µs
A
200
µs
A
Internal Receiver Electrical AC Parameters of the LIN Physical Layer LIN Receiver, RXD Load Conditions (CRXD): 20 pF
11.1
Propagation delay of
receiver (Figure 5-1 on
page 22)
11.2
Symmetry of receiver
propagation delay rising trx_sym = trx_pdr – trx_pdf
edge minus falling edge
trec_pd = max(trx_pdr, trx_pdf)
trx_pd
trx_sym
–2
6
µs
A
2
µs
A
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter
20
ATA6621
4887B–AUTO–01/06
ATA6621
5. Electrical Characteristics (Continued)
5V < VS < 18V, Tamb = –40°C to +125°C
No.
Parameters
Test Conditions
12
Watchdog Input PTRIG and NTRIG
Pin
Symbol
Min
3.5
12.1
Watchdog input highlevel threshold
V_HPTRIG
12.2
Watchdog input low
threshold
V_LPTRIG
12.3
Internal pull down PTRIG
Internal pull down PTRIG
RpdPTRIG
RpuNTRIG
125
VWD_OSC
2.3
ROSC
10
2.1
Typ
Max
Unit
Type*
V
A
1.5
V
A
200
kΩ
A
2.7
V
A
120
kΩ
A
3.1
µs
A
13
Watchdog Oscillator
13.1
Voltage at WD_OSC in
Normal Mode
13.2
Possible values of
resistor
13.3
Oscillator period
ROSC = 10 kΩ
tOSC
13.4
Oscillator period
ROSC = 51 kΩ
tOSC
10
12.5
15
µs
A
13.5
Oscillator period
ROSC = 91 kΩ
tOSC
17.9
22.4
26.8
µs
A
13.6
Oscillator period
ROSC = 120 kΩ
tOSC
23.2
29
34.8
µs
A
14
IWD_OSC = –250 µA
2.5
2.6
Watchdog Timing Relative to tOSC
14.1
Watchdog lead time after
reset
td
3922
cycles
A
14.2
Watchdog closed
window
t1
800
cycles
A
14.3
Watchdog open window
t2
840
cycles
A
14.4
Watchdog reset time
NRES
tnres
157
cycles
A
15
Temperature Monitor at Pin TEMP
15.1
Voltage at TEMP in
Normal Mode
(T = –40°C)
ITEMP = ±3 µA
VTEMP
2.35
2.7
V
A
15.1
Voltage at TEMP in
= ±3 µA
I
Normal Mode (T = 27°C) TEMP
VTEMP
2.0
2.35
V
A
15.1
Voltage at TEMP in
Normal Mode
(T = 125°C)
ITEMP = ±3 µA
VTEMP
1.4
1.9
V
A
15.2
Short current at TEMP
VTEMP = 0V
ITEMP
–30
15.3
Temperature gradient
16
16.1
–15
–5.4
VTC,TEMP
µA
A
mV/k
C
V
A
Wake Pin
High-level input voltage
VWAKEH
VS – 1V
16.2
Low-level input voltage
Initializes a wake-up signal
VWAKEL
–27
16.3
Wake pull-up current
VS < 27V, VWake = 0V
IWAKE
–30
16.4
High-level leakage
current
VS = 27V; VWake = 27V
IWAKEL
–5
VS + 0.3V
VS – 3.3V
–10
+5
V
A
µA
A
µA
A
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter
21
4887B–AUTO–01/06
Figure 5-1.
Definition of Bus Timing Parameters
tBit
tBit
tBit
TXD
(input to transmitting node)
tBus_dom(max)
tBus_rec(min)
Thresholds of
receiving node1
THRec(max)
VS
(Transceiver supply
of transmitting node)
THDom(max)
LIN Bus Signal
Thresholds of
receiving node2
THRec(min)
THDom(min)
tBus_dom(min)
tBus_rec(max)
RXD
(output of receiving node1)
trx_pdf(1)
trx_pdr(1)
RXD
(output of receiving node2)
trx_pdr(2)
22
trx_pdf(2)
ATA6621
4887B–AUTO–01/06
ATA6621
Figure 5-2.
Application Circuit
VBattery
22 µF
Master node
pull-up
100 nF
+
VCC
PTRIG
NTRIG
Microcontroller
33 kΩ
WAKE
GND
EN
Wake-up
switch
19
18
GND
17
1 kΩ
16
1
15
ATA6621
2
14
MLP 5 mm × 5 mm
0.65 mm pitch
20 lead
3
4
13
12
5
11
6
7
8
9
MODE
TM
WD_OSC
NRES
10 kΩ
LIN sub bus
20
EN
TEMP
10 kΩ
PVCC
+ 10 µF
VCC
100 nF
VS
1 nF
TXD
10
RXD
NC
RXD
NC
LIN
NTRIG
NC
PTRIG
220 pF
TXD
RESET
23
4887B–AUTO–01/06
Figure 5-3.
Application Circuit with External NPN
VBattery
100 nF
Master node
pull-up
MJD31C
+
1 nF
VS
20
EN
VCC
PTRIG
NTRIG
Microcontroller
33 kΩ
WAKE
GND
EN
Wake-up
switch
19
18
1 kΩ
GND
3Ω
10 kΩ
TEMP
+ 10 µF
VCC
100 nF
PVCC
2.2 µF
17
16
1
15
ATA6621
2
14
MLP 5 mm × 5 mm
0.65 mm pitch
20 lead
3
4
13
12
5
11
6
7
8
9
MODE
TM
WD_OSC
NRES
10 kΩ
LIN sub bus
100 µF +
TXD
10
RXD
NC
RXD
NC
LIN
NTRIG
NC
PTRIG
220 pF
TXD
RESET
24
ATA6621
4887B–AUTO–01/06
ATA6621
6. Ordering Information
Extended Type Number
ATA6621-PGQW
Package
Remarks
QFN20
Pb-free
7. Package Information
25
4887B–AUTO–01/06
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4887B–AUTO–01/06