Target Data

TLE 6286

Version 1.02

7

2001-10-15

In case the voltage regulator control input is not connected to INH output or the

microcontroller is active respectively, the TLE6286 can be set in normal operation mode

without a wake-up via the communication bus.

2.2

LIN Transceiver

The LIN Transceiver has already a pull up resistor of 30k

Ω as termination implemented.

There is also a diode in this path, to protect the circuit from feedback of voltages from

the bus line to the power supply. To configure the TLE 6286 as a master node, an

additional external termination resistor of 1k

Ω is required. To avoid reverse currents from

the bus line into the battery supply line in case of an unpowered node, it is also

recommended to place a diode in series to the external pull up. For small systems (low

bus capacitance) the EMC performance of the system is supported by an additional

capacitor of at least 1nF in the master node (see figure 6, application circuit).

combination with the required reverse polarity diode this prevents the device from

detecting power down conditions in case of negative transients on the supply line.

2.3

Voltage Regulator

The control amplifier compares a reference voltage, which is kept highly accurate by

resistance adjustment, to a voltage that is proportional to the output voltage and drives

the base of the series transistor via a buffer. Saturation control as a function of the load

current prevents any over-saturation of the power element. If the externally scaled down

output voltage at the reset threshold input drops below 1.35 V, the external reset delay

capacitor is discharged by the reset generator. When the voltage of the capacitor

reaches the lower threshold

V

until the upper threshold

V

GND, reset is triggered at an output voltage of typ. 4.65 V. A connected microcontroller

will be monitored through the watchdog logic. In case of missing pulses at pin W, the

reset output is set to low. The pulse sequence time can be set in a wide range with the

reset delay capacitor. The IC can be switched at the TTL-compatible, low-active inhibit

input. The IC also incorporates a number of internal circuits for protection against

overload, overtemperature, reverse polarity

2.4

Input Capacitor

The input capacitor

C

of approx. 1

input capacitance can be damped. The output capacitor is necessary for the stability of

the regulating circuit. Stability is guaranteed at values

≥ 22 µF and an ESR of ≤ 3 Ω

within the operating temperature range. For small tolerances of the reset delay the

spread of the capacitance of the delay capacitor and its temperature coefficient should

be noted.