Datasheet 14 Rev. 1.10
2019-12-11
TLD5542-1
H-Bridge DC/DC Controller with SPI Interface
Power Supply
5.1 Different Power States
TLD5542-1 has the following power states:
•SLEEP state
•IDLE state
•LIMP HOME state
•ACTIVE state
The transition between the power states is determined according to these variables after a filter time of max.
3 clock cycles:
•VIN level
•EN/INUVLO level
• IVCC level
• IVCC_EXT level
• VDD level
•LHI level
• DVCCTRL.IDLE bit state
The state diagram including the possible transitions is shown in Figure 6.
The Power-up condition is entered when the supply voltage V
VIN
exceed its minimum supply voltage threshold
V
VIN(ON)
.
SLEEP
When the device is powered it enters the SLEEP state, all outputs are OFF and the SPI registers are reset,
independently from the supply voltages at the pins VIN , VDD, IVCC, and IVCC_EXT. The current consumption
is low. Refer to parameters: I
VDD(SLEEP)
, and I
VIN(SLEEP)
.
The transition from SLEEP to ACTIVE state requires a specified time: t
ACTIVE
.
IDLE
In IDLE state, the current consumption of the device can reach the limits given by parameter I
VDD
(P_5.3.4). The
internal voltage regulator and IVCC linear regulator are working. Not all diagnosis functions are available
(refer to Chapter 10 for additional informations). In this state there is no switching activity, independently
from the supply voltages V
IN
, V
DD
, IVCC and IVCC_EXT. When V
DD
is available, the SPI registers are working and
SPI communication is possible.
Limp Home
The Limp Home state is beneficial to fulfill system safety requirements and provides the possibility to
maintain a defined current/voltage level on the output via a backup control circuitry. The backup control
circuitry turns on required loads during a malfunction of the µC. For detailed info, refer to Chapter 8.
When Limp Home state is entered, SPI registers are reset to their default values and SPI communication is
possible but only in read mode (SPI registers can be read but cannot be written). In order to regulate the
output current/voltage, it is necessary that V
IN
and IVCC_EXT are present and above their undervoltage
threshold.
ACTIVE
In active state the device will start switching activity to provide power at the output only when PWMI = HIGH.
To start the Highside gate drivers HSGD1,2 the voltage level V
BST1,2
- V
SWN1,2
needs to be above the threshold