T6819 ATMEL Corporation, T6819 Datasheet - Page 6

• Manufacturer Part Number: T6819
• Description: (T6819 / T6829) Dual Triple DMOS Output Driver
• Manufacturer: ATMEL Corporation

Power-supply Fail
Open-load Detection
Overtemperature
Protection
Short-circuit Protection
Inhibit
6
T6819/T6829
In case of undervoltage at Pin VS, the Power-Supply Fail bit (PSF) in the output register
is set and all outputs are disabled. To detect an undervoltage, its duration has to last
longer than the undervoltage detection delay time t
ately when supply voltage recovers normal operation value. The PSF bit stays high until
it is reset by the SRR bit in the input register.
If the open-load detection bit (OLD) is set to low, a pull-up current for each high-side
switch and a pull-down current for each low-side switch is turned on (open-load detec-
tion current I
load detection current, the corresponding bit of the output in the output register is set to
high.
Switching on an output stage with OLD bit set to low disables the open-load function for
this output.
If the junction temperature of one ore more output stages exceeds the thermal prewarn-
ing threshold, T
When the temperature falls below the thermal prewarning threshold, T
is reset. The TP bit can be read without transferring a complete 16-bit data word. The
status of TP is available at Pin DO with the falling edge of CS. After the microcontroller
has read this information, CS is set high and the data transfer is interrupted without
affecting the status of input and output registers.
If the junction temperature of an output stage exceeds the thermal shutdown threshold,
T
is set to low. Additional the overload detection bit (OVL) in the output register is set. The
output can be enabled again when the temperature falls below the thermal shutdown
threshold, T
mal prewarning and shutdown threshold avoids oscillations.
The output currents are limited by a current regulator. Overcurrent detection is activated
by writing a high to the OCS bit in the input register. When the current in an output stage
exceeds the overcurrent limitation and shut-down threshold, it is switched off after a
delay time (t
bit in the output register is set to low. For OCS = low the overcurrent shutdown is inac-
tive and the OVL bit is not set by an overcurrent. By writing a high to the SRR bit in the
input register the OVL bit is reset and the disabled outputs are enabled.
The SI bit in the input register has to be set to zero to inhibit the T6819/T6829.
All output stages are then turned off but the serial interface stays active. The current
consumption is reduced to less than 5 µA at Pin VS and less than 100 µA at Pin VCC.
The output stages can be activated again by bit SI = 1.
j switch off
, the affected output is disabled and the corresponding bit in the output register
jswitch on
dSd
OUT1-3
). The over-load detection bit (OVL) is set and the corresponding status
jPW set
). If the current through the external load does not reach the open-
and the SRR bit in the input register is set to high. Hysteresis of ther-
, the temperature prewarning bit (TP) in the output register is set.
dUV
. The outputs are enabled immedi-
jPW reset
4531A–BCD–10/02
, the Bit TP