Gain Control

DEVICE PROTECTION SYSTEM

Short-Circuit Protection

Overtemperature Protection

Undervoltage Protection (UVP) and Power-On Reset (POR)

TAS5701

The gain of the DAP is selected via two external gain pins (GAIN_0 and GAIN_1). Table 2 lists the corresponding

channel gain (for ALL channels) for GAIN_0 and GAIN_1 settings. Individual channel gain is not possible.

Changes to the GAIN_x terminals are latched in immediately on a rising edge of RESET. Changes to the

GAIN_x terminals while RESET is high are not allowed.

Table 2. Gain Control

GAIN_1

GAIN_0

CHANNEL GAIN (dB)

0

0

0

0

1

6

1

0

12

1

1

18

The TAS5701 contains advanced protection circuitry carefully designed to facilitate system integration and ease

of use, as well as to safeguard the device from permanent failure due to a wide range of fault conditions such as

short circuits, overtemperature, and undervoltage. The TAS5701 responds to a fault by immediately setting the

power stage in a high-impedance (Hi-Z) state and reporting the error on the FAULT pin (FAULT = 0); the device

automatically recovers when the fault condition has been removed.

The device has independent, fast-reacting current detectors on all high-side and low-side power-stage FETs. The

detector outputs are closely monitored by a protection system. If a high-current condition situation exists, i.e., the

power stage outputs are shorted, the protection system triggers a latching shutdown, resulting in the power stage

being set in the high-impedance (Hi-Z) state and FAULT going low. Overcurrent protection is not independent for

half-bridges A and B and, respectively, C and D. That is, if the bridge-tied load between half-bridges A and B

causes an overcurrent fault, half-bridges A, B, C, and D are shut down.

If the device junction temperature exceeds 150°C (nominal), the device is put into thermal shutdown, resulting in

all half-bridge outputs being set in the high-impedance (Hi-Z) state and FAULT going low. Once the temperature

decreases 30°C (typical), the device resumes normal operation.

The UVP and POR circuits of the TAS5701 fully protect the device in any power-up/down and brownout situation.

While powering up, the POR circuit resets the protection circuitry and ensures that all circuits are fully operational

when the VDD and GVDD_X supply voltages reach 9.6 V (typical). Although GVDD_x and VDD pins are

independently monitored, a supply voltage drop below the UVP threshold on any VDD or GVDD_x pin results in

all outputs immediately being set in the high-impedence (Hi-Z) state and FAULT pin being asserted low. The

device automatically resumes operation when all supply voltages have increased above the UVP threshold.

20

Submit Documentation Feedback

Copyright © 2008, Texas Instruments Incorporated

Product Folder Link(s): TAS5701