TCD6001 Datasheet, PDF (41/43 Pages) Tripath Technology Inc. – 6 CHANNEL CLASS-T DIGITAL AUDIO PROCESSOR USING DIGITAL POWER PROCESSINGTM TECHNOLOGY

Tripath Technology, Inc. – Preliminary Technical Information
Figure 4 shows the proper connection for the Over / Under voltage sense circuit for both the VPPSENSE
and VNNSENSE pins.
V5
VNN
R_VNN2
V5
R_VPP1
R_VNN1
VPP
R_VPP1
VNNSENSE
VPPSENSE
Figure 4 - Over / Under voltage sense circuit
The equation for calculating R_VPP1 is as follows:
R VPP1 = ^VPP
I VPPSENSE
Set R VPP2 = R VPP1 .
The equation for calculating R_VNNSENSE is as follows:
R VNN1 = ^VNN
IVNNSENSE
Set R VNN2 = 3 × R VNN1 .
I_VPPSENSE or I_VNNSENSE can be any of the currents shown in the Electrical Characteristics table for
VPPSENSE and VNNSENSE, respectively.
The two resistors, R_VPP2 and R_VNN2 compensate for the internal bias points. Thus, R_VPP1 and R_VNN1 can be
used for the direct calculation of the actual VPP and VNN trip voltages without considering the effect of
R_VPP2 and R_VNN2.
Using the resistor values from above, the actual minimum over voltage turn off points will be:
VPP = R × I MIN_OV_TUR N_OFF
VPP1 VPPSENSE (MIN_OV_TU RN_OFF)
VNN = −(R × I ) MIN_OV_TUR N_OFF
VNN1 VNNSENSE (MIN_OV_TU RN_OFF)
The other three trip points can be calculated using the same formula but inserting the appropriate I_VPPSENSE
(or I_VNNSENSE) current value. As stated earlier, the usable supply range is the difference between the
minimum overvoltage turn off and maximum under voltage turn-off for both the VPP and VNN supplies.
VPP RANGE = VPP MIN_OV_TUR N_OFF - VPP MAX_UV_TUR N_OFF
VNN RANGE = VNN MIN_OV_TUR N_OFF - VNN MAX_UV_TUR N_OFF
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TCD6001 – JL/Rev. 0.9/07.05