TDA7572TR STMicroelectronics, TDA7572TR Datasheet - Page 46

• Manufacturer Part Number: TDA7572TR
• Description: IC AMP PWM 200W BRIDGE 64HIQUAD
• Manufacturer: STMicroelectronics
• Type: Class Dr

Specifications of TDA7572TR

• Output Type: 1-Channel (Mono)
• Voltage - Supply: 8 V ~ 58 V
• Features: Digital Inputs, I²C, I²S, Mute, Short-Circuit and Thermal Protection, Standby
• Mounting Type: Surface Mount
• Package / Case: 64-HiQUAD
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Max Output Power X Channels @ Load: -

Step-up
9
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Step-up
A current boost controller is provided to allow high power operation in the 14V automotive
environment. This is a clocked PWM, current mode control block that drives an external
NFET. Following is present the application circuits.
Figure 10. Step-up application diagram
In the Step-up implemented is present a current control loop and a voltage one to fix the
output voltage. On the pin BSTVSense is reported the voltage VSP except for the gain of
Step-up, here imposed by the ratio R1 and R2. To improve stability, response time and
inductor requirements, an inner current control loop has been implemented. The inductor
parasitic resistance will be an adequate current sensor, and it is expected that with an RC
could be cancelled the zero of the boost inductor. Instead of use the parasitic resistor of
inductor a series sensing resistor could be used. The current sensing is take out by the pins
V14Sense and Csense.
To avoid destructive startup currents, soft startup is provided which functions by increasing
the allowed current limit using 4 steps roughly 4ms apart.
An overcurrent condition is declared if there is an extended period of high current.
Excessive current is detected (by monitoring the voltage across Csense and V14Sense
pins) for a period exceeding 20ms, which are considered to be caused by a fault condition,
are detected as Csense exceeding a voltage threshold and are handled by forcing a restart
of the soft start sequence when over-current is declared. Following are reported the
threshold of current limiting.
14V
Regulator
Step-Up
VSM
VSP
V14Sense
CSense
BSTGate
BSTVSense
BSTSource
VSM
+14V
Coil
R2
R1
AC00022
TDA7572