tda2500 Tripath Technology Inc., tda2500 Datasheet - Page 25

• Manufacturer Part Number: tda2500
• Description: Stereo Class-t Digital Audio Amplifier Driver Using Digital Power Processing Dpp
• Manufacturer: Tripath Technology Inc.

applications used the TA0105A in applications that had used the TA0102A, TA0103A and TA0104A,
prior.
It is recommended that customers using the TA0105A for low impedance drive convert to the TDA2500.
The main reason for this is improved over-current circuit linearity, especially at lower supply voltages as
well as the possibility of implementing an external over-current circuit to augment the internal half-wave
detection circuit.
For a given TA0105A low impedance application, the only components that require changing are the R
values. The values of R
compared to a TDA2500 design.
The procedure to determine the TDA2500 ROCR value is as follows:
1) Calculate the I
2) Calculate the required R
E MU LAT ING L EGAC Y TR I PA TH M ODUL E S U S ING A TDA2 500 MODU L E
The TDA2500 is structurally very similar to legacy hybrid modules such as TA0102A, TA0103A and
TA0104A. All of these modules employ the same block diagram. Items such as modulator gain and
supply range were fixed on the TA0102A, TA0103A and TA0104A. These items are adjustable on the
TDA2500. Thus, by choosing the proper value of external components that control these features, the
TDA2500 can emulate any of the legacy modules.
components are 200V, thus operating at lower voltages does not cause any problem assuming that the
external, user selectable, components are properly chosen.
For ease of use, the “voltage shifting” components are external to the TDA2500, allowing the user to
choose the voltage range, depending on the specific application. The most typical application is emulating
a TA0104A with its associated gain and voltage range. Below is a list of instructions along with diagrams
of the modifications needed to implement a “TA0104A” design.
intermediate range is needed, that the feedback and overvoltage/undervoltage resistors can be adjusted
based on the equations given in previous sections of the Application Information.
25
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For example, given R
Given I
operation)
Change the feedback resistors, R
channel) as both the FDBKNx and GNDKELVINx nodes need to have the series resistors
OC
I
(formula from the TA0105A data sheet)
I
R
(formula from the TDA2500 data sheet)
R
Use nearest 1% resistor value for R
For this example, the proper choice is 13.0k:, 1%.
OC
OC
OC
OCR
OCR
= 20.10A, R
= 4990 x (V
= 4990 x (0.97V – 15PA * (9100: + 8450:)) / ((9100: + 8450:) * 0.01:) = 20.10 A
point of the TA0105A design using R
= (4990 x V
= (4990 x 0.97V)/(20.10A * 0.01:+ 4990 * 34.5uA) = 12.97k:
FB
, R
OCR
VPP1
OCR
S
value for the TDA2500 using the TA0105A I
TOC
= 0.01:, V
, R
TOC
= 8.45K: and R
– I
VPP2
) / (I
BIAS
, R
OC
* (9100+R
VNN1
TOC
* R
FB
, to 18.7K, 1/4W. This requires a total of four resistors (2 per
, and R
= 0.97V and I
S
+ 4990 * I
S
= 0.01:
OCR
OCR
VNN2
)) / ((9100+R
.
OCR
BIAS
T r i p a t h T e c h n o l o g y , I n c . - T e c h n i c a l I n f o r m a t i o n
are constant for a given TA0105A design as
The voltage rating on the TDA2500 hybrid
BIAS
, R
)
S
= 34.5uA (bias value assumes +/-90V
, V
TOC
OCR
= 0.97V and I
It should be noted that if some
) * R
TDA2500 – KL/ Rev. 0.9/05.05
OC
S
)
value from step 1.
BIAS
of 15uA.
OCR